1bad91Z

iTrader: (1)

To Mike Crew's -

Where ya at? Any new developments? How's the car running?


400cidZ28 -

first off (and be realistic), how much $$$ is in your budget? Let me know and I can help you put together the best bang for the buck. Mid to low 12's can be built pretty easily, it's when you want to go faster than that, then your looking to spend some dough! :lala:

Mike (1bad91Z)

DAVECS1

iTrader: (2)

Well I guess I will jump into this super large post. After reading the whole thing my eyes are bloodshot. Well first off you all left me hanging. What cam!!!!!? I like the verfied numbers from Crews.
To clarify why I have subjected my self to reading this whole thing,, I have a motor on the stand that is similar to most in these post.

SDPC GM block 4 bolt mains 1 pc seal
LT1 powdered metal rods
Scat Crank filleted and radiused
TRW Forged pistons 2V relief
SDPC modified vortec heads
1.52 Comp roller tip rockers
Headman 1 5/8 headers
SDPC intake
Ported SLP runners
Stock Plenum

Why is it still on the Stand!!!? I cannot figure out what cam to use?

I am an electrical/mechanical engineer. On the side I fuel inject cars. My last was an 89 countach. I have tuned in some wild cams, but the results are less than lack luster at the strip. That is why I want my cam choic to be on the money. Since those of you IN THIS THREAD have given so much info on this subject I would like to give back.

Hear is the deal. I burn chips all the time. I will burn chips for you guys for the cost of shipping. Here are the stipulations

1. you must be in this thread before this post
2. I will only supply chips until my supply gets low then we recycle
3. The changes will be small.
4. The changes must be recommended by the owner ( i would be happy to discuss the changes you think need to be made)
5. I will not be held responsible for a damaged motor.
6. I will do the chips as I get to them and I can refuse service when I want.
7. I will not modify parameters that I have no idea about.

I felt that since we all do some good work here we should get something out of it. I am not doing this cause I am just a nice guy. I am doing it because I got some good info from this thread. The only thing I could ask is that someone pic one of these cams and dyno it!!!! If you have a request PM me

1bad91Z

iTrader: (1)

To DaveCS1 -

For your setup, I would recommend Comp Cams XR269HR-12 (The one Mike Crews is going with).

How to pick the right cam:

First, it's all about how much your intake and heads flow. After any port work etc.. you need to have your heads flow benched. Once you know what increment of lift that it flows it's peak cfm, pick a cam that has the closest possible lift. Example, If your heads flow peak cfm at .550 lift, you need a cam that has close to a .550 lift. If the heads only flowed 220 cfm or lower, (intake also flowing the same), you dont need that much duration (for heads that flow peak 220 cfm at .500 lift, you only need about 215-220 duration @ .050. The bigger the LSA (lobe separation angle) the better emissions the motor will make and it will be more streetable and idle friendly, however it will also hinder performance. The stock L98 cam has a 115* LSA.

112* LSA is still some what emission's friendly and it is a happy medium for performance, streetablity and idle quality. Also keep in mind that the heads' flow numbers are only as good as the intake supplying them with air. In an ideal heads/intake combo, the intake will flow as much as or close to what the heads flow.

This may not be the perfect technological explanation for choosing a cam, but this is how it was explained to me long ago.


Although I dont have a 383ci like Mike Crews, (Mine is a 355ci) , I went with the bigger Comp Cam (XR276HR-12) Slightly more lift and more duration.

Reasons why I chose my cam:

Since I have done Extensive porting/shaping to my complete intake setup, I will be utilizing more RPM's (my cam is good upto 5,800r's (the XR269 is good upto 5,500r's). Also, Mike Crews' heads dont have nearly the ammount of work that went into mine. With a higher flowing intake and higher flowing heads, the added duration of my cam will just make that much more power. If you dont have all the work that has been done to my heads/intake, I would go with the XR269 because with out all that extra port work, the XR276 would be overkill and may hinder performance. If you know some machinist that is bada$$ at porting, do everything that I had done to my heads. If not, you cant go wrong with the XR269 (it's still a really nice cam!) My heads outflowed AFR 190's on the flow bench when they were through porting them, bowl job, bigger exhaust valve, radius valve job, etc..... People think my cam is way to big for a LTR intake, but I have a good feeling that alot of people will be shocked. I hope this helps with your cam dilema!

Dave, you may have to wait a month before I get my car to the dyno. I should have it running in a week 1/2 to 2 weeks. Then I'm going to put 500 easy miles on the car to break in the new motor and give my ECM a chance to go through it's "learning curves". Then, it's off to the dyno, but rest assured, I'll post all the numbers (good or bad).

Mike (1bad91Z)

DAVECS1

iTrader: (2)

Thanks for the response. 1Bad91. My GTA is a 91. I agree with what you have said about cam selection. I am going with the SDPC modified heads. Maxium flow occurs around .505 stock, from what I have seen in the past and the motor SDPC put together. I have ported many heads, but I have not tried my hand at the vortecs yet and I no longer have access to an accurate flow bench, so I am not going to do much to them, I have studied the vortecs and I think there is some flow to be picked up behind the valve as long as you don't increase the throat to big and kill the air velocity. I have cleaned my heads up, but no serious porting. I then port matched from the heads to the plenum, siemiesing the entrance to the plenum. I think I am going with the XR269, and here is my .02 cents on the subject. With the LTR setup you are fighting a battle of surface area and friction. What I mean by this is as your air flow velocity increases the friction between the walls of the intake runners and the air increases creating a boundry layer that essentially shrinks your runner diameter, which in return ups your air velocity to a point. In a LTR setup the runner tract is long enough that you acually fully develop this boundry layer. The key is to reduce the length of this boundry layer by not introducing to much cam duration and opening up the runners with porting. Another secret I use is to never fully polish any runner surface. Just like a drag slick this increases friction and creates a bigger boundry layer, little imperfections will decrease the boundry layer without to much turbulance. If the runner track becomes to large you loose velocity and air will not fill the cylinder, this is when more duration is needed. LT1, mini ram, and SRs are effective because they create that happy medium of velocity and volume, by reducing runner surface area enough to retain velocity without creating much boundry layer interferance.

So basically what all this babble boils down to is the XR269 looks like a good choice because the duration looks about right to not create a boundry layer bottle neck, but still retain the velocity and volume of air that will make the combustion chambers work efficiently in the Vortec heads.

400cidz28

Very interesting info Dave. I've heard several people mention a vortec motor that SDPC built, is there a site where I can read about this motor? Is there any documentation? Thanks.

400cidz28

1bad91z,

I'm not sure how much $$$ is going to be in my budget. Heres the plan...I'm selling my truck to pay off the rest of my car and however much cash is left is going into the new motor. I figured anywhere between. 1,000 - 2,000. Keep in mind I already have the 400sbc with crank, rods and pistons, I may need to change the pistons depending on the heads I choose. I think I can get the heads for dealer cost if they're GM, so that saves some money. Feel free to give any suggestions.

Mike Crews

Hey Guys,

This is a tough time of the year for me - not much spare time around. Between work and hunting season, I don't have much time to get on the computer (or to work on my car). I have already started buying parts for the cam swap (cam, intake gaskets, intake bolts, etc.). I don't really know when I am actually going to get to the swap. To work on the IROC, I have to take my ZR1 out of the garage and leave it over at a friend's house/garage (we only have room for "1.5" cars in our garage), so his schedule affects my schedule. But I'll get to it as soon as I can (yes - including dyno numbers & track times).

DAVECS1, that's a very generous offer on the chip burning issue - Thank You. I will give that some thought. I'm going to use my curent chip (Crews8) as the starting point with the new cam (XR269).

I'm too am still "dying" to see you dyno numbers Mike (1bad91Z) -Good Luck!

Later Guys,

Mike.........

DAVECS1

iTrader: (2)

sorry double post

DAVECS1

iTrader: (2)

I actually had my mind made up on the LPE 211/219 cam until I read this post. I went ahead and purchased the XR269 cam. So I guess we will see what happens. I move into a new house in december so my engine swap may not be done till February. Nothing like moving in the middle of an engine build.
I have a question that maybe one of you can answer. I am contemplating powdercoating my intake, do you think this will inhibit heat transfer enough to make a noticeable difference on power.

Mike Crews

Hey DAVECS1, I don't think that powder coating your intake will make any appreciable difference in performance due to reduced heat transfer. This is just my opinion, and is not based on any quantifiable data. My intake is coated with LPE silver/grey ZR1 engine paint (left over from painting several ZR1 engines).

Later,

Mike......

DownUnderIROC

I've decided to go for the Comp Cams XR264-12 in my LTR Vortec headed 350.

1bad91Z

iTrader: (1)

To Mike Crews - yea, I myself am dying to crank the beast up! Hopefully this weekend, that will become a reality!

To DownUnder - why did you choose the 264 cam? Not criticizing, just curious!

To All - powder coating the intake is a BAD idea! Powder coating is like a thick plastic heat resistant coating. Yes, it will resist heat from the outside, but it will also RETAIN heat on the inside (where you DONT want it)!! Think about it, It would be alot harder to disapate heat if you have a thick coated barrier keeping the heat in.

Just my $.02

Mike (1bad91Z)

DownUnderIROC

1bad, I chose the 264 for a number of reasons.....

I'll be running AS&M LTR's with stock -062 Vortec heads on my 350, so I think my best option is to choose a cam that builds on the awesome low-end & mid-range torque of the TPI system. I plan to add a stall converter of around 2500 RPM as well.

I like the idea of the agressive lobes in the CC XR series, they are current technology, unlike other TPI cams that have been around for sometime. The Accel 74211 is a proven choice with the LTR setup, but I like to go my own way and I saved a bunch with the 264... I think it will run OK. I reckon that hot-rodding and street machining is all about doing your own thing on a budget and getting a good result for your efforts. And its fun

I'm aiming for a reliable daily driver in Sydney, which is a city of around 4.5mil ppl and loads of traffic snarls. I hope to give 12.9 secs a nudge with my setup when its done, on street tyres and in full street trim.

Shagwell

It has to be official by now, this is the best, most informative, non-arguementative post ever! - I just finally finished reading all the posts. - Anyhow, I thought I would through in my $.02 on top of the $100 total of all the previous $.02. First off, I would love to see your dyno numbers Mike(1bad91Z). My 355 TPI has a little less intake work, less cam, and a crappy(but better than stock) chip, but really good vortec heads, and it pushed 302rwhp and 373 rwtq. The car has run a best of 13.2 @ 112 with a 1.81 60' time. I have sub-frame connectors and LCA's, but no adjustable toque arm, hence my crappy 60 foots. My cam is 278/296 .495/.495. Duration at .050 is around your CC XR276. I'm not sure exactally what the @ .050 duration is on it(I really hate not knowing for sure). I'm going to switch out the top end of the motor for a set of full ported and polished 993's, change the cam, pistons(get compression back from the 62cc vortecs) and put a carb and intake on it. I sold my TPI for an ungodly amount to a guy at the track who "..just had to have it". Anywho, I've got another 350 TPI set-up(the original off my car) and intend on building a mild vortec headed 383 LTR set-up for my full-size Blazer.

- Mike Crews, I think you'll be happy with your cam choice. Are you going to go ahead and put on the Hooker LT's? Also I would really recomend stepping up to full-on roller rockers. They are really worth the money, and as 1bad91Z said, most of the better brands will clear the stock valve covers. Harland Sharp claims 15-40 more hp between stock stamped steel rockers and true roller rockers. There is a lot of friction to be lost and a loss of valve train friction equates to an easier revving engine. I may not have a vast amount of experience at age 19, but my dad drag raced long before I was born, and still does to this day. He has moved on to blown cars, but his knowledge is in NA cars. He always said to me that if you don't have the money to do it right the first time, then do you have the money to do it again? So I have always gone the extra mile to build a really nice engine. I may not make the most horsepower, but mine will be making that horsepower for 150,000 miles. Thats how I build a motor.

It sounds to me like you both(Mike and Mike) have really good motors. No matter what anyone says about building it right the first time, you will always be changing things to see if you could have done better. - sorry this is so long, but this is a heck of a post to reply too. - good luck both of you, I'll keep in touch on here. I'm anxiously awaiting dyno results from both of you, and anyone who wants, feel free to shoot me a question or comment.

Shagwell

Another thing, I'm running 3.27's in a BW 9-bolt. My converter is a Dayco 2500-2800 stall. I was always told that a stall converter stalls when you flash it, meaning leave at an idle and mash the throttle. My 60' times were worse this way, but it was due to traction. The converter would stall higher, and it was more like dumping a clutch at around 2600. Excessive wheel spin, but the motor/car launched better this way. So, I usually left against my brakes at around 1700. While changing my engine configuration I will be putting in an new adjustable torque arm(finally) and now have much better tires than previously used, so hopefully my times, 1/4 and 60', will improve. - BTW, Mike you still got your 3.70's? If you do and want to sell them, how much? My carb motor will have a higher power band, and the 3.70's would really help me. - thanks guys for the great posts - the information in the post is irreplaceable.

- on another note, what ever happened to warbird? -

Mike Crews

Hi Shagwell,

Thanks for the vote of confidence on the new cam. I ordered the cam a few days ago, and they said it would take 2 weeks to get (bummer). My water pump also just went bad, and the new Stewart Stage 1 pump was on my doorstep tonight when I got home. I'm just going to let the car sit for two weeks until I get the cam, then do the cam change and the water pump at the same time to save some trouble.

Sorry, but I sold my gears a long time ago.

I am not doing the Hooker LT headers.

112 is a great mph, your car is running very good. You are only making a few more rwhp than me, but I can't get past 108 mph. Hopefully the new cam will change that.

Well, got to go.

Later,

Mike..........

Shagwell

Mike -

Yeah, my hp is there, but my torque isn't. The extra arm(stroke) you have has a lot to do with it, but my cam had too much duration . - Anyhow, good luck with the cam change. - Where did you get the water pump from, and how much? Mine is starting to act up, and I figure I should upgrade from the stock pump. Also, who makes gears for a 9-bolt? I wanted yours because I haven't been able to find anything for mine.

thanks,
Justin.......

1bad91Z

iTrader: (1)

To Mike Crews - Hey! Why are you scrapping the LT project? That's the tenth or two your missing! Oh well, I understand, it was a BIG pain in the a$$ when I put mine in! Let me know how the car runs with the new cam. I'm getting really close to finishing my project as well.



To Shagwell - Richmond makes the gears you need. Also, your cam has MORE duration than mine!! You could have made more HP with a smaller cam. You may want to invest in a better convertor (Vigilante or a yank) 2,800 lock-up stall. 112mph in the 1/4 is good for mid 12's! Somethings wrong with your traction and maybe launch technique. I ran a 12.92 @ 109mph in my friends 2001 Z-28 (LS-1 with exhaust and some bolt-ons) and his car is 3480 lbs. by itself!! I'm expecting to put arround 350 hp / 400 + ft. lbs. to the wheels (that's the best quess I have). But who knows, it could be a turd like the Magnum TPI car and only put 250 to the ground or by some freak chance, make 400 rwhp! Good or bad, I will post the numbers after it's broken in and all the bugs are lined out.

L8r,
Mike (1bad91Z)

Mike Crews

Shagwell - Regarding your gears, I also think there is also a guy on the board (9bolt.com and/or Differential Solutions) that sells all sorts of 9 bolt stuff. My clutches are starting to slip (imagine that with 130k miles and 500 + ft/lbs of flywheel tq), so I need to rebuild my rear end soon.

I got the water pump from Stewart. Just search for "water pump" in the Aftermarket Parts forum, and you will get all the info you need. I picked a Stewart Satge 1 pump, as it met my needs, and was only $92 shipped to my doorstep for the pump and a new hi flow thermostat ($69.95 just for the pump). I looked at the stage 2 pump, but I just didn't need it, and it was twice the cost. My car has always run very cool (even with the A/C on in traffic), and the Stewart pump will still flow way better that my old FlowKooler pump.

Hey Mike - No LTs right now. I'm just doing one thing at a time right now, mostly just due to the fact that I don't have a lot of "disposable income" laying around right (just bought my wife a new '03 Dodge Quad Cab Hemi truck) - that's what she wanted. Plus the cam swap is pretty easy, and I just don't have the energy to fool with and aggravating project right now.

Later - Mike.........

86IROCNJ

Hey Mike (Crews), great job if i have not already complimented previously! This is a great post too i should add, pretty informative. My main question is, if it has not been posted already, what type of intake are you running? I know about your LTRs, i am wondering about the "CAI". The only reason i ask is b/c it seems to be working and it seems not to be restrictive. That was one of the problems on that Magnum TPI car, the air intake. I am just curious to see what you are using since my motor is almost "plugged" in and i am using the stock intake for now with a "custom" ram air set up but i am still undecided on a really good intake. Any info would be great and once again, nice work! Lets just say i wish i was running low 12's. Later-Bryan

Shagwell

To 1bad91Z - I know my duration was bigger. It sucked too! That cam was crap for an LTR car. To much duration, too little lift. It made the HP, so my mph was good. Problem was that the torque came in in a funky power band, so it didn't put out to good of E.T.'s. I know traction was my main issue, but that should be solved with the adjustable torque arm. The stock one couldn't handle(duh). - thanks for the info on the gears to both Mikes.
As for the converter, I got it new from Dayco for $200, thats hard to beat. - it works for now

later, justin...

86IROCNJ

I was going to go with a Dayco but found out from this site that they are not that much better than stock quality, so i decided on the Vigilante. A little pricey but it is worth it in the long run. From my experience it has been you pay for what you get. Sometimes i wonder if i could've went a different way but i just did not want to take a chance! Did you get an oil/tranny cooler too?

Mike Crews

86IROCNJ - Thanks for the compliment. When you say "CAI", I'm thinking that you mean cold air intake. My air intake is one that I bought years ago. It's the one that has two curved ducts that take cold air in from around the foglights and "rams" it straight into the two K&N filters (then though a modified Bosch MAF). It drops in and replaces the old plastic peice that hold the air folters. I've had it so long, I can't even remember who makes it. With the hood open, it appears as a stock IROC twin snorkel intake. I really don't know what I could do that would work any better.

You WILL like the Vigilante converter, it's a jam up peice, and is money well spent. I have no tranny cooler, as the folks at Precision (Vigilante) said that I didn't need one. I run Mobil 1 trans fluid, and have no trans problems at all.

Later - Mike.........

Shagwell

What did you guys pay for your Vigilante? It may be worth it someday, but not at the moment. After just building my new engine I'm a little spent for cash. My Dayco may not be great, but I haven't had a problem, and I drive pretty hard. Then again, if I do have a problem, I get it replaced for free(same connection getting it for $200). I do run a tranny cooler. I'm also running three fans. I have a factory dual fan, and one I put in underneath the front of the car blowing air in front of the rad. - to much stop and go in Florida temps. With the 'bird, the closed nose kills air flow. My cooler is placed on top of the third fan, laying horizontal in front of the air dam. -


later,

justin

Mike Crews

Hey Justin - I paid $699 for mine, and I ordered it right from Precision Industries. They were very helpful, professional, and a pleasure to deal with.

Later - Mike........

BlueByU

Mike Crews - I was wondering if the AS&M semi-siamesed runners have any huge welds on them like TPIS had. I can't find a picture of those anywhere.

slp_firehawk

just wondering how that magazine (forget which one did it) put vortec heads on a 350, along with lt4 hotcam, 1.6 rr, runners and i think 58 mm throttle body, i'm sure i'm missing a couple other things i don't have the article handy, but how'd they get close to 400 rwhp?

1bad91Z

iTrader: (1)

..............with a carb. A Holley 750 double pumper, I think.


Mike (1bad91Z)

87Formula391S/C

iTrader: (1)

Mike (either lol)
are the AS&M runners made by AZ Speed&Marine

thanks Sammy

86IROCNJ

Maybe he means another article with tpi. Last time i checked carbs didn't have 58mm tbs! Those numbers do sound realistic with a carb though. And 87Formula, i believe those are the runners you are thinking about, thats what those abriviations are! They are a pretty good company and make quality parts. They are a bit pricey though, no more than TPIS.

87Formula391S/C

iTrader: (1)

Thanks 86IROCNJ

Mike Crews

Hey Guys,

Yes - the AS&M SS runners are indeed Arizona Speed & Marine Semi-Siamesed Long (Large) Tube Runners (what a mouthful). They were $475 (ouch!). And yes, they have similar welds to the old TPIS siamesed runners, but I have only seen the TPIS siamesed runners in pictures. The AS&M SS runners are basically a set of AS&M Large Tube Runners that have been sectioned out and welded together for about 1/2 (maybe a bit less) of the total length. They are a very high quality peice. The welds are there, but they are "nice welds". I painted mine with LPE ZR1 engine paint, but you can still see the welds. I don't think they look bad at all. They come from AS&M with a nice silver finish on them, and look great just the way they come. I just wanted something a little different color. The AS&M website has pictures, but I don't know what you can really see in them. They knocked a full 0.1+ off of my 1/4 mile time (I swithed from AS&M "regular" LTRs).

STILL waiting for my new cam to arrive..........

Later,

Mike......

1bad91Z

iTrader: (1)

To Mike Crews -

I have a dumb question. Are Vortec head pushrods a different length than stock L98 pushrods? The comp cam push rods I have in my new motor said years 89 and up and they are the same length as my stock L98 pushrods. Do I have the right ones? The reason why I'm asking is due to the problems that I am having (in my post "I finally have all the parts needed to finish the motor").

Thanks,
Mike (1bad91Z)

Mike Crews

Hey Mike - I just read your full post last night. I have just been working so many hours, that I can't get on the computer like I used to.

Anyway, I used a new set of GMPP push rods that I bought from Jim Pace (PACEPARTS.com). I bought my heads at the same time, and Pace indicated that the GMPP push rods were fine for the vortec heads. The GM part number is 12371041 (for the kit), a single push rod # is 102411740. The hyraulic roller motors use a different push rod than a non roller motor, but I don't know exactly what the difference is. I accidentally almost bought a set that wasn't for a roller motor. So, to answer you question - I am running a normal set of GMPP L98 push rods, so I assume that they are normal L98 length. I know that standard length for non-roller push rods is 7.724", but I don't know if the roller pushrods are the same or not (I can't find it in my books, but I'll keep looking).

That's all I know to tell you right now. I'm going to re-read your post and see if I can muster any "intelligent" suggestions for you.

Later (good luck)

Mike........

kwikgta

The hydraulic roller motors use a 7.200" pushrod.

Mike Crews

kwikGTA - Thanks for the info. I never knew what the length of the roller motor pushrods was. I was wondering, as I was reading your sig. - how kwik are you (1/4)?

Thanks Again - Mike........

kwikgta

I haven't been to the track in about 1&1/2 yrs., but last time I went I was running in the high 12.50's. I actually have AS &M SS runners And not a SuperRam( I never installed it. I am in the process of gathering parts for a 6" rod 383, But I will stay with the sportsman II's (they are paid for).

HardCorps

Great thread.
Mike Crews, I like the setup of your motor. It is what I would like to build for TWO vehicles that I currently own. My 3rd Gen convert is dying for a new motor that is fast, that is driven DAILY and travels ALOT. What are you getting gas mileage now after all your mods since your first MPG post? Once you have your new cam in please post MPG as well. My other vehicle is a 67 Bronco whose drivetrain is now ALL chevy. The torque out of the 383 is perfect for offroading and turning my 36 x 14.50 tires. Also street driven AND drag raced at over 5200 pounds!
Anyone else around 12-13 seconds please post MPG as well.
One last request. Mike, please once you have time, post a detailed list breaking down your motor. You have done an excellent job so far at listing everything and detailing everything, but for us copycats out there it would be nice to have it all in one place. Thanks again!
Mike (yes..one more Mike to add to the confusion)

Mike Crews

kwikGTA - 12.5 is awesome! Maybe your 383 will put you into the 11s. I'm hoping for 11.99 (or less) when I get the new cam in. I'm confident that I'll be right there in the 12.1 - 11.9 range. But, you never really know until it's all said and done. The car could run slower with the new cam (but I hope not).

Hi Mike III (HardCorps). I haven't measured my gas milage since that first post. But it has seemed to be pretty consistent since then. I'm getting ready to pull the engine (maybe over the Thanksgiving Holidays), so the next mileage that I give will indeed be with the new cam. But, my new cam still is not here yet.

Mike (III) , please look closely at my sig, and see what other specific questions that you might have as far as my combo goes. I tried to be as specific as I could in the sig w/o making it too long. My motor is really nothing special. I just think that matching the combo and spending money where it really counts is why my car runs like it does. For example, I still have the stock 2 bolt block and stock rods (very cost effective/cheap), but I went big on my torque converter and suspension. I think the only things not in my sig are 1.6 intake, 1.5 exhaust, and a new/stock GM 400 balancer. Like I said, let me know what other specific questions that you have.

Later - Mike.........

Shagwell

As you await your cam, we all still await to here how it runs... I'd love to see some big dyno #'s and an 11 sec pass... good luck!

later, justin...

kwikgta

Mike C, I thought I would also mention that I have the same SLP cam in my car as the one you are looking at (makes good power). I will probably reuse it on the 383 to save money.

Mike Crews

kwikGTA - I'm assuming that you have the SLP 51006 cam?? I tried to buy that cam a month or so ago, but they have discontinued it. The SLP cam is 218/224 just like the XR269, but it is ground @ 114 LSA on a 114 intake centerline (0* ground in advance). The CC XR269 is 218/224, but is a 112 LSA on a 108 intake centerline (4* ground in advance). I guess I will install it straight up (if I ever get it). Did you install the SLP cam straight up, or did you maybe retard it a degree or so? I know that some people (like GMHTP) recommend installing cams in LTR cars 1* - 1.5* retarded. I installed my 74211 straight up (as LPE recommended). I'm thinking/hoping that this cam will work great in a 383.

Oh yea, Mike III (HardCorps), I forgot one other little thing on my engine. I have a Milodon Diamond Stripper windage tray. It took a little "modification" to get it in (rod bolts were hitting it), but it fits now.

Later - Mike.........

kwikgta

Yea Mike that is the cam I've got, I didn't know that it had been discontinued though. I installed it straight up.
I am like you in the fact that I am going to retain the long runner set up, just because I like the looks of it! I've chosen to go with the 6" rods because I read in GMHTP that the long runner set ups respond better with longer rods .
I think that your set up runs awesome: retained the long runner set up, low buck approach, runs 12.30's. What more could someone ask for! Keep tuning, I think there is more left.

slp_firehawk

how do the SLP Runners fit on the L98, do any modifications have to be made? also what kind of gains should i expect from putting semi siamesed slp runners and fully porting the plenum to fit the runners, if i have full exhaust - headers, y pipe with no cats and slp 3 inch exhaust.

OMINOUS_87

slp_firehawk

Check the link below as they have mods that are very close to yours.

Mark

http://www.thirdgenresource.com/phot....html?cid=1049

Mike Crews

Hi slp_firehawk,

I was running SLP runners on my old 350, and they bolted right on, no problem. Some of the bolts were a bit difficult to get to, but not really a big problem if you use the extended 5/16 allen wrench supplied by SLP. As far as the AS&M SS runners go, I picked up 0.15 in the quarter, and about 1 -1 .5 mph (on my 383) when I switched from the AS&M "regular" LTRs to the semi-siamesed version, so they do help some (at least on my car). The car seems to pull harder on the top end with the SS runners. On the dyno, I picked up about 10 hp aross the entire rpm range, about 20 hp above 4500 rpm, and about 10 -15 ft/lbs of torque across the entire rpm range. So, like I said, they worked well on my car.

My new cam is still not in. Comp Cams was waiting on new cores. They received the cores right before Thanksgiving, and they said I should have my cam next week sometime.

Later - Mike..........

slp_firehawk

thanks mike, another thing, about how much did it cost to get your plenum ported? or did you do it yourself, i'm guessing around 100..? i have no clue. i'm hoping with the headers and taking out no cats, and the new runners with plenum i'll get down into high 13's....my last best time was a 14.43, think i'm asking for too much?

i'm pretty much going to go with the setup of sdpc intake, vortec heads, 52 mmtb, lt4 hot cam and 1.6 rr, along with the stuff i already have.

scoggin dickey claimed 350 hp and 400 ft lbs with that setup, but then again that's their products, but we'll see. i just want a streetable setup that will get me in mid 12's, i'd be very happy with that. oh and i have to get subframe connectors too, i have a full hotchkis suspension, besides those.

Mike Crews

Hey slp - I did my own plenum porting. If you have access to an air compressor and a die grinder, you can do it yourself as well. It's not that difficult. I think that TPIS charges around $90 to port the runner outlets to large tube size, and to do the throttle body inlets to 52 or 58mm. Like I said, try and do it yourself. Based solely on what I've seen at my local track, I think that headers, runners, and some pleunum porting should get you into the 14.0 to 13.8 range with no problem. The new setup that you describe should get you into the low 13s or high 12s, but mid 12s might be tough. However, you just never know until you do your mods and and take it to the track - there are so many other varibles that come into play (just my opinions).

Later - Mike.......

slp_firehawk

well, i'm just looking for a good setup right now that is faster than what it is for the time being...not really too picky on if its mid 12's yet, i'll get to that when i actually have the money.

another thing, my transmission is acting up, well it has 112k miles on it so i should be glad that it hasn't gone yet, but the shift from 1st to 2nd kinda slips into it....like it'll shift at 4500-5000, then rpms will hold at about 4300 for a fraction of a second then it will go down to whatever rpm it is, i forget, 3500 or so. i ended up buying a corvette servo cause i heard that firms up the 1-2 shift, but i have yet to install it cause i don't want to make it worse. have any ideas what it could be?

also, later down the road, how would you be able to change the shift points on the 700r4?

jason

Shagwell

Get that camshaft yet Mike?