Guest

I am thinking on pulling my Vortec heads (L31 crate motor heads with 1.94i/ 1.50e and .420 SAFE max lift springs) and going to clean them up. I live in So Cal so I have to hide this application from the smog ****'s.

What I first have plans to do is to pull them down to bare and slightly port (mainly debur the port casting and polish the exhaust sides.

I am then going to send them over to have the valves and seats remachined for 2.02/1.60 and spring pockets checked for higher lift spring installs.

Now, MY MAIN GOAL is to lighten the valve train since I do have a hydrualic roller cam currently in the motor. This cam is a .414/.428 and 111 lobe sep. I am buying is just Crane Cams extuded Gold 1.6 rockers and leaving the existing cam which will yeild .442/.457.
What I am trying to acheve is just a very radical lightweeight valvetrain so as to pull a little higher rpm's without lifter collapse. THIS IS A DAILY DRIVER MOTOR! I have a single plane MPFI manifold that I have run on it and this motor will spin nicely pulling hard currently to 5500 rpms but will sometimes collapse lifters. I currently have the TBI dualplane maifold back onto it for smog and it will only spin about 47-4800rpms with this intake.

I do not mind spending the money for an exotic valvetrain. anyone have some imput as to what valves, locks, retainers, seals, seats, and I also want to thread the rocker studs to 3/8" which I hear I can safely do and get rid of the crappy press in 3/8" studs.

I was thinking something along the lines of hollow stem alloy valves with titanium retainers and spring pressures to withstand about .525 lift IN CASE I DO DECIDE TO LATER boost the cam lift a tad more, I just do not want too much unneeded pressure by installing .575 springs

Any imput , feedback, or criticizm to what i am doing is greatly appreciated. I am currious if anyone has worked over a set of Vortec L31 heads other than simply buying slightly better RHS heads. I want alot better valvetrain than the E-tecs and RHS heads.

Dean

ps- Part #'s on suggestions would be greatly appreciated. I am currently looking at Manley Extreme duty valves undercut, but am wondering if there is something lighter I can use since I do not need that radical of heat temp and strength in valves- I just need lightness and flow.

305sbc

iTrader: (3)

https://www.thirdgen.org/forums/tech...tec-heads.html

Guest

Thank, but that link does not help my needs. As stated, I am not looking to mickeymouse something, I do not mind spending the money to do things correctly. I want the proper parts----correct valve lengths, no shims, good seals that do not need to be cut down. I am not looking to save a buck over doing things the best.

What I did read off of that and was one reason I was asking for critisizm is someeone their did say to leave the 1.94 intake sizes and just go to larger exhaust vlave sizes. I was looking at flow # and the intake numbers are strong up to .500 with the 1.94, the exhaust sides drop in comparison to the 160cc range compared to other similar heads with the 180 range like TrickFlows.
I do not want to use GM parts, I would rather go more percise aftermarket in springs so the LS stuff does not interest me at all. That post says they are wider 8mm stems and longer so those alone will add weight to the valve, plus they have to be shimmed in some cases.

Now with that said, I AM NO EXPERT on cylinder head machining or its requirements in a marraige of componant fitment (I am a chassis expert in suspension geometry) ....SO, I am asking for some solid advice on this wonderful tech forum (I have been around this site for 10 years but this is my first post ever on the engine forum, would appreciate some soild help from the more experienced veterans so I can spend my money and time ONCE wisely. Please jsut don't send me off on some link for used parts.

So now, lets say I keep the 1.94 valve size but go with NEW performance undercut valves, will I still need to change or grind the seats different based on a valve choice?

it really is the valves, guides, retainers and keepers I am lost on marraige of componants, the spring length, width, seat pressure and installed heights I know how to figure as long as I know what valve. I will just have a machinist work the spring pockets tot he exact installed hieghts I need for the spring choice I decide. I really am asking opinions on Valves brands, retainers I would like to go to Titanium of some brand, who makes the best reliable seals for street use that will fit this intended application, what lightweight locks and keepers will work best (what angle, what grooves etc- this is the stuff I do not know)

Can someone give me good accurate data on a high end build with good hollow stem valves 1.94/1.6, where to get seats (or will a machine shop handle this part- low down time of this vehicle is important, this is why I want to order things first and not have headaches), where to buy seals, locks, retainers, who is the best you recommend. I do not do this sort of thing daily, I would like info from someone who does. Every set of heads I have ever bought were over the counter performance heads exept fot he heads on my Vette were done through my father's knowledge 30 years ago at Blairs speed shop and are still working our needs today over 8500prms in a 327 SBC.

Help me get the best application I can for my desires discribed in my opening post, thank you.

It is a daily driver build, not a weekend garage queen so reliability is of the essence. I do not need this car with some .600 lift cam, just with a little extra umps now and then when I raise the rpms witht he combo I have so I do not get lifter collapse.

Dean

skinny z

I've installed the Comp beehive springs. With the reduced mass of the spring as well as the smaller retainer the result is a lighter and more stable valvetrain. With the addition of the titanium retainer and the hollow stem valves you suggest, you will certainly have a lightened pile of components.

http://www.compperformancegroupstore...Category_Code=



There is an added benefit of reduced harmonics with regard to valve float too. Typically the harmonics will now occur higher up in the RPM range, out of range for TYPICAL street driven performance engines.
While at the machine shop, the studs were replaced with the screw in type as well as guide plates. This excluded the use of the Vortec rail or self guiding rocker. With the addition of a 1.6 ratio Pro Magnum rocker, the push rod holes were enlarged. This also ensured there would be no binding between the head and the new guide plates.
Not sure if any of this is of any use, however it is real world experience. With this combo and a XR276HR cam, my 350 pulls well past it's peak horsepower rpm of 5700+/-. I've bounced off 7000rpm more than once with no ill effects. The original (stock) valvetrain bent an exhaust valve on a missed shift (6500+).

five7kid

iTrader: (14)

The intake ports are fine as they are. The 2.02" valves won't help.

The exhaust is what needs work. 1.60" valves will help, along with the usual port clean-up, guide airfoiling, polishing, etc.

In general, Vortec ports are much cleaner cast than older SBC castings, and the short side radius is much smoother.

Beehives are pretty good springs. With titanium retainers and the Manley valves, you should be in good shape. With no more lift than you're doing, you shouldn't have any problems with valve float or harmonics.

DeathStarr89

iTrader: (1)

I run the Comp Cams 26915's (LSx springs) at .549 lift and spin to 7K with a roller cam. Never had any valve float or collapsed lifters. Beehives are a good investment.


If you use Comp hardware (retainers and locks) make sure to check the installed height for every spring. Comp has put out some bad batches of locks that cause the retainers to sit a little high in some applications. I had a rocker rubbing one for 3K miles before i found it.

Guest

As I appreciate the input those of you have given, nobody yet has read my questions and answered them. I do not need help on springs, I asked what valves would anyone recommend, not the ones you would not recommend. Who has the best valves, locks, retainers and keepers. If I can mix and match companies for best results I am game for that.

Culd somebody re read my questions above and answer those? I would tend to believe SOMEONE on here is educated enough to give me part #'s and professional advice. I asked specific questions.

Dean

I am looking on websites and catalogs and the info between bvarious companies and componants are vague.

I have checked Sumit, Jegs for generic results, and have looked a Ferrea, and Manley's sites. What else could anyone recommend I look at to educate myself since no one can answer my exact questions?

I KNOW what I am looking for result wise, I just need to know how to get there. I am well aware of the weights, lift, spring pressures and all that as I have already stated. The behive springs might be too much seat pressure for what I need- that is premature to look at until I find my valves, locks and retainers and seals and then see what kind of material I have to work with in the spring pockets. Thatks for the spring aadvice, but I already stated I do NOT need that info.

I see this kind of crap all day long on the suspension forum where people for some reason can not read the questions, I do not know how else to ask this for the 3rd time? If you do not have the answers for what I ask, please do not answer me with useless knowledge that I already know. I was specific in what I need.

Guest

fact1-I am not going to .549 lift
fact 2- I am not spinning 7K

Why do I need this info?

Guest

Thank you. I am aware of the clean castings and the need to just slightly deburr them. I had assumptions on the needlessness of the 2.02 vlave, so thank you that was addressed.

As for your quote above? I am not looking for good, I am looking for the best with part #'s in lightweight hollowstem valves and titanium Locks and retainers. Manley extreme valves are heavier than some of the others they sells, but are they worth the extra weight or is their better lighter recommendations. I am asking specific, not looking for generic answers that will remder me "Good, or "ok".
Could you please be more specific, So far I have no answers to my questions.
I also asked about the stock L31 intake seats? I had several questions I asked. SHould I re list them so everyone can read what I asked again?

Dean

3rdgenmaro

iTrader: (9)

Why dont you look around for one of the top engine builders in your area. Not many people on here are going to be able to answer your questions to the extent that you want.

You have nascar connections. Find a builder that also builds engines for steet cars.

just curious.

DeathStarr89

iTrader: (1)

You spoke of collapsing lifters at 5500, i was merely showing that with a more extreme cam and even higher RPM's the beehive springs perform well and i have no collapsing lifters and no float.


I was actually going to put up more info on how i modified my lifters to handle the abuse but decided against it. I'm also running sodium filled valves, forgot to post that as well.

Besides, you said..

five7kid

iTrader: (14)

To be honest with you, it sounds like overkill since you aren't going to .55" lift and spinning to 7k RPMs. The beehives will control harmonics throughout the RPM range (high RPMs isn't the only place harmonics rear their ugly heads). I only mentioned titanium retainers because you did. Heavy valves are more of a problem at high lift and RPMs, so I'd concentrate more on the flow improvements of the valves chosen.

Heavy roller lifters are best controlled by a rev kit. Much cheaper and more effective than trying to lighten up the rest of the valve train.

305sbc

iTrader: (3)

The spring pocket itself is already a known factor. You choose your valve, spring, and retainer combination based on the lift range that you want. Your installed height is the important factor and can be manipulated by using different retainers or locks, different valve length, machining the spring pockets deeper, or using spring cups or shims under the springs.

Valve float and collapsing lifters are not the same thing. The chance that you are collapsing lifters to the point of losing valvetrain control is pretty much zero.


The part of the screw-in stud that threads into the head is 7/16". They ALL are, even the ones that are 3/8" on the topside where the rocker goes on.

All valves are alloy.

An undercut Manley intake valve weighs 120 grams which is 64% heavier than a stock Z06 intake valve.
You said that 8mm is wider. I'm not sure what you're talking about there, but your stock valves are 11/32" diameter or 0.343".
An 8mm valve is 0.315" which is much thinner and lighter.
In fact, the undercut part of the Manley valve you mention is 8mm diameter.

In your posts I've seen you shun the idea of using a slightly longer valve, but talk about not wanting too much seat pressure.
A slightly longer valve-stem lowers seat pressure and increases available space for lift before the retainer contacts the guide or seal. Normal practice is to machine the top of the guide for clearance, but you criticized that as well.
FYI, it's the seat pressure that will most times save you from running into valve float. Over-the-nose pressure and lifter collapse are almost never a factor for a street driven engine.

The fact is that the GM LSX parts are lighter than what you have now, and likely lighter than what you plan to buy, to include titanium valves if you go that route. Most Ti valves are longer than stock by much more than the tiny amount of difference between SBC1 valves and LSX valves. They will not be lighter in weight than the steel Z06 valves.
As far as precision goes, that is in the machine work, and not the fact that the valves were made by either Manley or GM.

FYI, Ti valves generally have to have a coating on the stem to keep them from galling in the guide. This tendency and requirement make them a poor choice for street driven engines. The cost of Ti valves, machining of such, and the periodic reconditioning is extremely high in comparison to other options.

I prefer SBI seals - Viton with metal clamp.
You can download their online catalog to look up exact sizing. You'll need to know what the final O.D. size is on the top of your guide and the valve-stem diameter. You will need a slight interference fit at both places, so don't match to exact size.

You will not find (for your application) lighter valves than the hollow 8mm Z06 valves, the beehive springs, the stock LSX retainers, or the stock LSX locks mentioned in the links I gave. You can buy them new.
By the way keepers and locks are two names for the same thing.

One exception is the steel LSX retainer. If you want you can spend the extra money for the Ti versions from Comp Cams which will save you all of 4 grams each.

Seat inserts are normally for aluminum heads, unless your seats have been damaged, or you have to upgrade the material for durability/thermal reasons as with a high output turbo application. Your seats are in the base metal now and can just be opened up to the new size you need.

Maybe you're used to getting spoon-fed everything on the suspension forum, - I don't know, but from your posts it seems to me that you really didn't read all of the information at those links I posted.

I port and recondition cylinder heads. That's what I do. I'm not a mind-reader, but judging from things you've posted here, there is quite a bit of "useless" knowledge that you really do not know.

Maybe it's me, but you seem to come across as rude to the people offering you information. I can understand that you may not be a people-person, and have little understanding of setting up cylinder heads, so I'm just going to state that my best advice is to look at the information at those links thoroughly (because I'm not going to spoon-feed particulars to you), or you could just take your heads to machine shop specializing in this type of work and have them set everything up correctly.

Taking some advice from the web and combining that with your incomplete and sometimes faulty knowledge is just not going to work out for you.

Oh, and try to be nice to the person who will be doing your machine work and/or assembly.

Good luck with your project. I think you're going to need it.

Dustytrix

iTrader: (3)

Very well put, glad you stepped up to the plate.

Guest

I do not want to mickmouse things. I stated I want to use proper valves so I do not have to add shims. If I need more valve height I am not going that far with lift so I should easily be able to get more height if needed by having the spring pockets machined a little more in depth. I appreciate the info, but I did not ask for this, I have this covered. I can see lower in this post though that since the LS valves are lighter then this would be the only way to use them is with shims since they are taller. If they are in fact that much lighter then this is appealing and I will need to check into the safety and longevity of shims. I just like as few parts as possible- my opinion is there is less to fail that way.

Yes, I do know the difference between valve float and lifter colapse. I am not popping or backfiring, I am experiencing an occational sudden rpm loss that fluctuates between about 5200 and 5700 rpms when I have the single plane manifold on there. Most of the time I can pull no problem- but just occationally it would jusdt drop off funny at various rpms, not the same spot- but again, only on less occations but frequent enough to want to fix the problem. I am sure this valvetrain was not intended to see average of 5500 rpms on a factory L31 Vortec motor.




Thank you, I am aware of this since the press in studs are already 3/8" the tap woiuld have to be larger even though the topsides are still 3/8 for the rockers. But good info I guess to list for anyone welse looking at this post for the future- I will leave it at that.



The first answer in that post you linked, "Attilla the fun" said you can not use LS valves in a Vortec head because they are longer and you have different stem widths. you later state you can if you use different bronze guides but you do not state if there is machining involved- I guess yes this is my bad assuming the ls valves were wider also since they are longer. I did not go and search the convertion between 11/32 and 8mm, my appologise for stating this backwards, I was confused by what I read there by two different people.

I want to obtain the lowest spring pressure I can get away safely with. I do not want to use shims if I can avoid it(talked about this already above) Where did I ever critize the idea of machining the top of the guide? I in fact talked about getting my install height out of machining the spring pocket- is not the guide part of that pocke area?--Yes. I do not know where you are getting this misinterpetation from, I think you need to read better what I ask, I have been very polite and said a few times in my first posts "thank You". You are jumping to your own conclusions ill of what I really wrote.

I said from the start, I want the lightest valve assembly I can get- I did state "Hollow stem alloy valves, and titanium locks and retainers". My mistake on the alloy knowing that titanium is an alloy also- innocent mistake that you know what I ment and are staing an obvious small mistake in my typing, never the less, I should have listed "hollow stem stainless steel valves and titanium locks & retainers. I am NOT going to the outragious expense for titanium valves for this application. Money is not a problem, but spending for titanium valves on this appliction is just plain foolish.

This is great to hear of the ls valves being less weight. I did not know this and this info was not listed in that post link. The only thing talked about in LS valve weight was you quote, "You can use LS1 or the lighter LS6 valves. The retainers and keepers are the same no matter LS1 or LS6. I normally use used or take-out valves, retainers, keepers, and spring locators from LS1 heads." That quote doesd not compare the LS weights to the Vortec head weights. That post link lacks any education info on valve weights to a novice like me when comparing L31 setups to LS setups. It just talks that LS6 is lighter than LS1.

I addressed this already. I did not ask about titanium valve, only titanium retainers and locks.



This is fantastic and helpful. It answers one of my original questions

I will need to right now look into the beehive springs and see if I can gather info to compare their varoious install heights with my current setup and see if I can use all this without shims. As stated before, I just do not feel comforatable with extra parts if not necessary, just my opinion- yes it may be wrong the wrong opinion though, my gut alwayys tells me fewer parts is more realiable and less stuff to fail.


Thank you. Like I asked in my frist post, one of my questions was with the valves anyone recommends can, can you also tell me what locks I need in the way of degrees with the valves you are recommending? I am tryin gto learn stuff like whats the difference in quality and reliabilty between things like 7* and 10* locks? what the difference in single or double grooved valves? etc. It is confusing for a novice like me to match what valve with what keeper and why? Is there a better or worse? Maybe they both work?

Thank you! This is very helpful info and answers one of my questions
What is this about 30* grinding though? I have read it in that link. Should I ask for that and please tell me how I would ask for that phrased properly- I would like to learn the terms. What are my other options if there is anything I need to know that could help me better in flow smoothness, not necessarily volume- I do realise volume increases will decrease velocity so I do not need a response to this subject. I ask this more pertaining to eliminating turbulance.


Now as for the guy that asdked if I have connections in NASCAR, yes I do, I will not see those connections for a few more months. I am good aquiantances with Bill Thomas jr. who if any of you know is related to Bill Thomas of the GM Cheetah project back in the 60's. I will be asking Bill to do the work for me when I see him next, I just want to have all the parts bought and waiting so I can expidite this when mid april comes and he is back in town for the local race season.

In what I do in NASCAR is minor league stuff. We deal in spec motors. We have seals engines that can only be handles by one of 4 listed engine builders and sealed so we can not touch the internals. I have spec valve springs I change- with that said, we do not get into custom stuff here- it keeps costs down. I have my hands full in chassis work as well as drivetrain maintinace(rearends, trans, carb rebuilds, etc as well as constantly repairing and welding damge and bodywork and rejigging suspension squareness and baseline setups for next race day. This is not the 50million plus dollar a year big leagues. We do not have the major engine builders with all the state of the art technology, its the guys who all have connections and not necesarily knowledge being the best- the old political game of "its not what you know, but who you know" ALot of dynasty families in local AND national racing politics. Our motors are basically spec crate motors not tou=ched by these engine sources other than they are purchased solely through these 4 sources and sealed prior to us being able to accept them. All engine serial #'s are recorded by NASCAR officials. Any motor change needs to be re certified with officials prior to qualifying or race use.

Alot of people hear NASCAR and think everything is white glove, it is not. That is only the top two divisions of "Cup" and "Busch" cars. Divison 3 West and Arca cars and on down are more grass roots and limited budgets. I am a divison 4 Supertruck Crewcheif and have also done some Divison 3 crew work and live pitstops at a few given opportunities to fill in when extra help was needed. These positions are often taken by friends and family members over outside better experiences persons.---like I said, lots of politics in racing.

ps- my resume as a crewcheif in a 17 race history in Supertrucks is 2 wins and 5 3rd place finshes as well as taking my driver 3rd in championshippoints in 2008 out of 41 truck my rookie year. Last year we ran into finacial difficulties at the start of the year with the poor economy and the result of lost sponsorship funds. That team owner went belly up broke in 2009 and did not finish the year. We were in 2nd place 3 races into 2009 with one win already when I was told the money dried up and I was cut for a "new race car shop"sponsor that wanted to act as crewcheif. They finished that year in 9th with that racecar shops support- very frustrating for me. I hope more oportunities will come for me in the future.

Dean

Guest

There is nothing wrong with shims, in fact many times they came on heads from the factory. They're a complete non issue IMO. They rest on the head and are held in place by the spring and in use are not moving parts. I also would not try to run the lightest spring pressure possible, if anything I would err on the higher side. Chances are if you really have a valve float issue its because of the reason mentioned above, too little seat pressure. As far as locks, with what you are planning its not going to matter. The 10 degree locks have a wider angle as you are looking at the side of the valve stem and have less chance to pull through the retainer, but with your cam that should never happen anyway.

For what its worth, my dads car is running the stock 2.02/1.60 valves that came with the AFR heads (not exactly light valves either, pretty sure they were Manley not undercut), the double springs that were on them (not sure of the origins of these) and some Comp Cams Ti retainers because they came with the heads and I figured I may as well use them. They're shimmed, although I dont know how much exactly because I did not set them up myself. We're running what I personally consider to be a lot of pressure both on the seat and open, but thats what my machinist recommended and I trust him. I guess with the XFI profile and .576/.570 lift it was necessary. There is a 6800 RPM limiter on it, and its bounced off that a few times. So far, so good. Previously, I had some aluminum L98 heads on it that I set up myself, I had shims on it, stock valves, a single spring with very likely more closed and open pressure than you have, some Comp cams steel 7 degree retainers and locks, and at one point the same RPM limiter and no issues with that setup either.

I dont know if I'd go with LS components, but if you are only after reducing weight then maybe that is the best option. However, I dont know that there is much point or much to be gained in doing everything you can to reduce the weight of the valvetrain. I would follow the advice of running a larger exhaust valve, maybe the beehives shimmed appropriately, you will need retainers for those anyway (pick whichever you want 7 or 10, IMO its not going to matter for you), and have someone competent backcut the valves and machine the seats. There is a lot to be gained there, if its done correctly.

I would have posted up some actual numbers for you but my brain is completely fried today and I'm not even sure I can spell my name, besides tell you what shims and seat pressures I was using. I have an idea, but thats about it. I had to look up the lift values for the XFI cam, and on a normal day I could tell you what the as installed valve events were off the top of my head. So.... I'm sure someone else will give you a good number to go with. Your cam is fairly tame, its not going to take a whole lot more than a stock spring.

skinny z

.

3rdgenmaro

iTrader: (9)

That was me asking about the NASCAR stuff Dean. Wasnt sure what level you were in. Didnt know that you was running spec motors. Id love to do that stuff, but I dont have the knowledge, skill, or funding.

Best of luck. One request is to post back up what you end up doing and how it turns out. Im curious to this as well.

Guest

Thank guys for the responses.

As for me being short tolerance? I am a straight to the point person. I believe in facts. I type very direct (you should see me try and text- what a frikin joke that is) I am much more a people person where I talk to people face to face. Madmax (Chris) and his father have gotten to know that about me and we have become good friends in person- they really questioned my typing attitude at first also. I know I lack expression skills, I just like my questions answered directly as for just what I ask and nothing more.

I sometimes ask things wrong. When i realize that, I clean up my questions once I get a little feedback and see I am not being clear. It is so hard to read minds on here like 305sbc has stated- so lets me make my mind more clear.
I see now what I first wrote and will ask this one stand alone question- this is what I was first and formost after once I realised that yes I should just stick with the 1.94 intake valve (heck, it works and its lighter weight than the 2.02),........

....What are the weights of the L31 valves I currently have, and what options can people recommend for a replacement upgrade that is the lighest valves in stock length 1.94/1.6 valves?

I was and still am looking for grams weights. Manley has this info, but who else makes valves that I can find this info to compare to. I have tried to find Ferrea spec, Mildon, I checked Summits site and Jegs.... I am not having luck finding this info.


Chris, you know this vehicle, its no rocketship but it is very respectful for something 4800 lbs (Safty cage and frame completely welded for strength and carrying 4000lb bed payloads. It ill never be at the level of something like your dads car or my Vette. I will never build it to that. This truck- just like my Camaro build was for my ex wife as a daily driver grocery getter, will never see a drag strip. It just gets me across town sometimes as fast as I need. I want it bulletproof and realiable. I know a lightweight Valvetrain is what I need for what I have. This truck generaly see a full 34 gal tank of fuel a week.

When do I have this colapse problems. When I have loads in it and I am climbing hills with not only 4800lb vehicle weight, but also payload weights and I will be hammering it up steep hills like Knoll Ranch Rd in Anaheim Hills or the Imerial coming back south from 91fwy up that steep grade. If I stop at a light on the hill and then come off it, the motor will strain more throttling up hill longer in the gears and staying in the higher rpmrange through shifts. Tis is were I was experiencing lifter collapse. This is why I want to lighten the valve train and keep the spring pressure down lower (But a safe lower that will still handle the rpm and lift I need) so as to keep the most pressure OFF the lifters.

I also stated I am adding 1.6 rockers. I am having problems with collapsing right now with 1.5 rocker and ligher springs with less overall lift- this is why I want to go lighter. I want to keep the hydrualic roller lifters sice this tuck will probably see another 500,000 miles in the next 20 years like I got out of the last motor (hard miles- Thank you Synthetic oil)

My plan this year is to finish the brakes first (Z06 brakes will finish the theme of the 'Vetruck') and do these heads so I can get that single plane amnifold back onto there and oick back up the 75hp I am down. I went from a 13.4 1/4 to a 14.6 just switching back to this dual plan TBI setup from the 8 injector MPFI.
SO this leads to the biggy... I am gearing towards that TCI 6X aauto 6 speed trans with paddle shifters Once this is in, the motor will stay in the higher rpms under throttle...I want the valve train light, I do not want collapse problems nor do I want to change the longevity of the current hydrualic roller lifter. I am trying to get the best of both worlds for my more rare and specific need. My opinion is, I feel I know what I need, hence my direct questions.

So to reiterate my question above:
....What are the weights of the L31 valves I currently have, and what options can people recommend for a replacement upgrade that is the lighest valves in stock length 1.94/1.6 valves?

I was and still am looking for grams weights. Manley has this info, but who else makes valves that I can find this info to compare to. I have tried to find Ferrea spec, Mildon, I checked Summits site and Jegs.... I am not having luck finding this info.

Thank you, Dean
ps- Remeber, I stated I am NOT looking for titanium valves..TY.

skinny z

Fair enough.

305sbc

iTrader: (3)

I can only verify what I have posted in these threads.
If you follow the other link in my post here:
https://www.thirdgen.org/forums/tech...ml#post4432686

You will see the other info that I posted. This is why it seems to me that you did not read the info I had posted in the first link.

I found your Mickey Mouse remarks insulting. In the world of cylinder head machining it is actually more Mickey Mouse to machine spring pockets to differing heights in order to set at even seat pressure. The accepted and proven best way to set exact heights is by using shims. A shim will only have a problem if the bottom of the spring has burrs, which can be fixed by dressing the spring bottoms, or if the shim is made of a material that is too soft. There are many generic type shims out there, and most machine shops have found a type that work well for them. I prefer stainless shims from MSC Industrial. It is also to your advantage to use a shim with an inner spring locator, depending on the spring type you go with. The LSX type locators work well for beehive type springs.

There's nothing wrong with machining the spring pockets, but they should all have the same depth. Machining the top of the guides is considered a separate operation, though it can sometimes be done with the same cutter tool. Both the top and the O.D. of the guide can be machined, to include the guide boss when applicable. A spring pocket can be machined deeper and/or wider in some cases. In some cases a spring cup will be necessary.

When reconditioning or upgrading used heads, it is most common for the guides to be refreshed with sleeves/liners, or replaced to bring valve-stem to guide clearance back into spec. This is already a needed machining operation.
Without spending any more money, the right guide liners can be used to convert an 11/32" guide to fit an 8mm valve.
The part # I've used in the past is KLI851ST , also through SBI, but check with them for current part #.

I don't know if he's a sponsor here, but I get my Z06 valves from Shaun Carter at SMC Performance - valvegod@aol.com

I posted the link to the Z06 valve conversion information for you because it looks to me like a perfect all-around solution for what you want to do.
If it were my job to do, I'd use the following:

2002+ Z06 hollow steel valves int/exh 74grams/64grams
1998+ LSX stock retainers & locks 14grams retainer/lock combo
1998+ LSX stock inner spring locators (without integral seal)
CompCams # 26918 beehive valvesprings - will fit stock spring pocket O.D.
Comp 26918 spring is 73 grams

Valve seals - Viton with metal ring & band:
SBI # 122-1316 for 11/32" valves and 0.560" guide top O.D.
SBI # 122-1053 for 8mm valves and 0.500" guide top O.D.

I would have the guide tops machined about 0.100" lower, and to a 0.500" O.D. , then have the guides reamed for install of the bronze 8mm guide liners.

I don't have a Vortec V8 head in my shop right now but I have some Vortec V6 heads, so I did a quick mock up with LSX valves. These V6 heads have the 0.860" O.D. guide boss, and so would not need spring locators with the Comp 26918 springs. The Comp springs fit fine with no machining of the pocket or guide boss. If your guide bosses are smaller O.D., then I would machine the spring pockets deeper by 0.045" , and use a stock LSX inner spring locator/shim (0.035" thick).

Using these parts, (assuming spring locators not necessary) I would set the springs up with a 1.85" installed height, where the Comp 26918 springs give 130 lbs of seat pressure. This might require machining the spring pockets by about 0.045".

With 0.500" lift and 1.85" installed height, the spring clearance to bind would be 0.230". Without machining the guide top, the retainer to seal (0.150" seal height) clearance would be 0.700", and 0.800" with the 0.100" machining. There is no danger of part interference, with shims or not.

For comparison, a normal sized Ti retainer weighs 15 grams alone, and between 20 and 25 grams with locks, depending on the type of locks used.
The stock steel LSX retainer & lock combo is 14 grams.
The top of a beehive spring is the part of the mass that counts, and is obviously much smaller than even a straight-wound 1.25" spring.

This isn't what I'd call a Mickey Mouse conversion or upgrade. It has significant advantages in many ways. The Z06 valves are back-cut from the factory and flow better than 11/32" valves due to their thinner stems. The quality of the metal is excellent. GM doesn't use cheap parts in its flagship corvette. The Comp 26918 is a pretty serious spring for street use, and especially so when combined with a valve&retainer weight of only 88 grams intake, and 78 grams for exhaust.

It sounds like you're using a factory camshaft. Factory cams are excellent for achieving stable high RPM capability with modified valvetrain. Factory cams have relatively lazy closing ramps for street longevity, and that makes it easier for the springs to control the valve motion. Regardless of where your engine combination peaks power at, or the physical RPM limitation of your bottom end, the light valvetrain I have described combined with 130 lbs of seat pressure have your RPM requirement more than covered with lots of room to spare. If you swap cams in the future and want more seat pressure you could shim the springs to 1.80" for 143 lbs, or to 1.77" for 150 lbs on the seat.

In low lift and mild camshaft applications, a 30* valve seat has some advantages due to increases in low lift air-flow. Factory style SBC1 heads with mild camshafts respond well. If done at the same time as increasing the valve head diameter, then it requires a little less machining to open up the throat area to match the new seat cut.
The Z06 valves are 2.00"/1.55" diameter. That's a small increase in diameter over what you have now and would require minimal machining in either case, so nothing wrong with you sticking with a standard 45* seat.

There is also the option to simply cut the 2.00" intake valve down to match your 1.94" valve seat you have currently, and same for the exhaust. The valves would lose another couple of grams in the process and valve shrouding would not be increased. This operation goes quickly with a carbide style valve cutter, but takes longer on a valve grinder.

Radiusing both the valves and seats to form a smooth venturi between the valve and seat gains a significant amount of low lift flow. This widens the power band at both ends, and allows a higher power output with a relatively smaller camshaft.

If for some reason after this valvetrain upgrade you still worried about the lifters collapsing, I would recommend upgrading to a CompCams model like the retro-fit hydraulic roller. They are heavy, but as I stated earlier the lifter weight is generally a non-factor for a street driven engine.

In my experience, most people having lifter problems in street engines do so because they run with too much lifter preload which will allow pump-up during (spring caused) valve float. There is a spring inside the lifter plunger. The more you compress that spring, the more pressure is taken away from your valvespring's seat pressure, which in turn can cause early valve float. Once valve float is happening, the clearance is taken up in the valvetrain by the lifter plunger pumping up to a higher position, which then keeps the valves from seating. The result is severe valve float & surge, and the possibility of catastrophic engine failure.

The easy fix is to run minimal preload on the lifter plunger. I try to keep my own to 0.005" or less. A strong beehive style spring like the Comp 24918 should keep you out of valve float with no other modification.

I lied. I said that I wouldn't provide particulars, but I got frustrated after seeing that you hadn't followed the other link.

305sbc

iTrader: (3)

The Vortec V6 heads in my shop have factory 1.94"/1.50" valves and should be the same as what you have, so I put them on my scale along with some other valves that were on or near the workbench for comparison.
All below are 11/32" stem dia.

Vortec Intake 1.94" - 110 grams
Exhaust 1.50" - 92g

Ferrea undercut Intake 2.08" - 125g
Exhaust 1.60" - 103g

Ferrea not undercut Intake 1.94" - 117g

Manley undercut Intake 2.02" - 120g
Exhaust 1.60" - 112g

Manley not undercut Exhaust 1.60" - 106g

Manley 1.25" steel retainer & locks - 25g

Elgin slightly undercut Exhaust 1.625" - 103g

Manley Titanium not undercut Intake 2.05" - 84g

Victory +0.100" Titanium slightly undercut Intake 2.02" - 103g

Besides lots of stock SBC1 and LSX stuff, that's all I have right now.

Guest

Already backcut and 74 grams. Well, that explains all the fanfare about the Z06 valves. I guess I've been away from engine stuff too long.

Guest

What was the other issue you were having, or was this it? I cant picture this being the cause of what is going on, it sounds like it is something else.

Guest

You know, sometimes acting arrogant and pissing people off so they prove a point pays off.

305sbc, you my friend are a god. that was the kind of high grade tech I was looking for.

Where do I send the donation check?

On a serious note, I think had I note come accross in that manor I do not think I would have gotten the advance info you gave me here, Please know that the time you took to write that info is VERY aprreciated and will not go in vain, I myself spend lots of hours typing responsse for people here mainly on the suspension forums, so I for one am VERY respectful of someone talking the time to do the same for me.

:cheers:

Dean

ps- you have sold me so much on your knowledge I wish you lived near me I would give you the job solely based on the level of education you provided me on this post.

Guest

I think you were refering to me having to pull the Edelbrock single plane MPFI setup off the truck to smog it. The system is running with decent power but not optimum tune since it runs off the TBI computer with only 2 drivers I have been told. Apparantly the TBI computer can only batch fire each bank of injectors so it ran durty on the smog rvrn though Edelcrock claims an EO statis on this truck with this intake. Their escape goat is the rest of the truck is too extensively modified and I would have to put everything else back to stock for their system to run clean (Asswipes)I pulled the system off to smog it last year when i got the truck back running after the accident. My next smog is this April only 15months later so I just left the TBI setup on their for now and am waiting to do head work and some new computer work after I just smog the TBI setup first. Then if I have troubles with it I have two years to work any new bugs out and have the guys over at Turbo City repin a new Vortec computer into it and run it off the crank trigger this L31 has stock.

Guest

It dawned on me the irony of this final outcome.

I never first mentioned until later down in this post these heads were for my truck, but what I did not say was this is a Z06 concept truck and the irony of now actually using a partial Z06 valvetrain in it of all the combinations that are out there

Vette Pewter Pearl metallic paint
Vette shark gill fenders
Vette Z06 hood cowl (Cervini Fiberglass)
Vette Z06 6piston brakes (about 50% finished)
Vette Z06 wheels
Vette Z06 floor mats

Whats the irony of z06 valvetrain of all things for you to recommend me for this vehicle....Cool

Dean

ps This truck would have a complete Vette rearend IF I did not have to use it for carrying loads- but then again if I did not need a truck I probable would have never built this. It has a Currie 9" and assited airride for loads in the rear with 4 front and 4 rear shocks. I cut the front suspension off, ground the chasis mounts, then rebuilt my own custom suspension with better camber gains, roll center, and anti dive. Front arms are custom HRP parts.

You can see more photos of it in my profile page

I have achieved 152mph in this thing downhill grade with the front splitter on it- not bad for an areodynamic brick. it won't get above 135-138 without the splitter.

Guest

Here's a video of me playing chase vehicle to a VW Karmann Ghia at Toyota Speedway drags.
4800 lb truck
L31 crate motor
Vortec TBI dual plane manifold (Down probably 70 hp with single plane mpfi manifold off currently)
electric waterpump
Thorley headers
lots of bolt on goodies, best of everything spark, fuel, etc. underdrive pulleys, billet distrubutor
Carbon fiber driveshaft
Currie 9" with detroit locker and 3.70's
Long story on the trans- lets just say my great DY700 is gone due to someone plugging th ecase and building the line pressure through the roof- current trans is a POS stocker with a shift kit.

Anyways, I have never run this truck in an 1/8 or 1/4 but realized when downloading footage of Gordons Ghia that I actually was hanging with the cars that run and had to lift when I started catching the right lane car. You can hear how this motor revs with the dual plane manifold. I put the single plane MPFI back onto there and I rev about 800rpms higher.

ps- This is a bad run for the Ghia. It usually goes 7.1x range @ 96. 2 stage box was set wrong limiting the car to 7k instead of 9500 thanks to his sons foulup.

Pretty funny when the chase vehicle becomes the 3rd drag car.
http://www.youtube.com/user/V6rsr#p/a/u/0/KKa8D_97UW8

3rdgenmaro

iTrader: (9)

Any updates Dean on how this project is going?

Guest

Sorry, I do not frequent this board and just saw this looking back for the info. I stil have plans for this, just that money has been tight and I have been out of work for months due to this lousy economy, lack of workshop, and a bad back injury.Thank god for family support.

A friend has been helping me get this truck up and running and we towed it out to the track for some testing. I let him drive it the second run, I drov the first and third runs. You can hear how see runs coming down the back straight at about 5400 rpms. This is the single plane manifold, but with only the TBI injectors being used and not the multiport system even thought the manifold installed with the 8 manifold based injectors unplugged electronically and no fuel feed.

The truck is just really siting collecting dust. Its really one big sleeper. Thiose little Miat'as on the first run are turning lap times of 47 sec range completely stripped to a racing weight of about 1500 lbs. I tip the scales at 4800 lbs and ran a 53 sec run my second run third in video, Nick drove the second run to 55.9 second laptime, my frst was a 54.9 with way too high of Tire pressure in the rears) after learning the course on the first run.

On the first lap, once I hit the left hairpin I brke the steering wormgear and the wheel was modulating locking as I pulled to to the left. mde things real interesting and hard to control. You see it takes forever in the video to get around to the left on that infeild hairpin, it jut would not turn.

Alot of fun though, I needed to get alittle aggression out- even though my back is still in pain, g forces hurt right now. Thise exotic seats I had in my Camaro were great for situations like this with the nice large sidebolsters. The seats in the truck- although custom, are no wheere near the support or comfort of the Momo seats in the Camaro, nor the price range. I was limited to space doing the 3 set thing out of the factory bench seat mount.

Anyways, turn up the volume- you gotta love the NASCAR boomtube muffler as it roars down the back straight.
http://www.youtube.com/watch?v=IMGiTsGLRUQ