Hello fellow F-buddys,
I have a simple question that I think most of u will be able to help me with. I am rebuilding my 305 motor out of my 1984 Z28 vin code"G". I have been looking all over the net for a place to buy a master rebuild kit. I have found a ton of places that sell them but I am looking for the best price. Prices range dramaticly from place to place. I am looking for a mild increase not a high proformance rebuild. I know I can go real cheap with parts i.e. rings pistons, but I do not want a motor that last 20,0000 miles. I know some one must know of a reliable place that sells kits cheap. Another thing I have heard that the 305 and the 350 have alot of interchangable parts why is it the price for a rebuild on a 350 is so much less than on a 305. I thank u all for your input
Thanks Kelly

 

only differance in a 305 and 350 would be rings most all other parts would be the same. i never look for a "kit" i buy the parts i want and when i have all the parts in one place it becomes a "kit". to some people, and you appear to be one of them, price is the over riding factor when it comes to building an engine. northern would be the first place i looked if i were buying on line for OEM type parts. for preformance parts i'd look at jegs or doug herbert.

 

It's beyond merely foolish to buy engine rebuild parts for your own car on the sole basis of price. I'd suggest giving a little more weight in your decision-making matrix to what you're getting.

Like ede said, nobody "makes" "kits". They take a box of these pistons, those rings, some other bearings, gaskets from whoever, etc. etc. and put them in a box, and call it a "kit". So, the thing you really need to be doing, instead of looking for the "cheapest" "kit" that somebody "makes", is picking out parts that fit your needs and budget, and then shopping for those parts.

Obviously if you're looking to simply rebuild a "H" motor, you're not aiming for the highest performance thing that you can find; so you don't need to waste money on romantic-sounding high-dollar racing parts. On the other hand, you don't want a motor that runs even slower than what it already does, burns oil uncontrollably in 10,000 miles, and has to be replaced again next year, which is what you risk ending up with if you limit yourself to the "cheapest" "kit" you can find.

For the closest thing to one-stop shopping that you're going to find, I'd suggest looking in Summit and getting Sterling H534P hypereutectic pistons (flat-top like the HO motor, rather than dished like the low-perf LG4 you have.... instant free HP), Speed Pro standard-gap moly rings, Speed Pro / Federal Mogul (preferably NOT Clevite) bearings, a Fel Pro complete engine gasket set, and a Mr Gasket 26 oil pump pressure relief spring. Then go to Auto Zone and get a Melling M55 oil pump, a 55S screen for it, and a IS-55E oil pump drive rod.

Have your block bored and honed with a torque plate at a racing shop, not yerbasic "cheapest" place that claims to be able to enlarge the holes; and get your stock crank turned.

Heads are a different matter. They're not subject to a "kit" at all. They are where power is made, and where a little more money on better parts and machine work can REALLY pay off in driving satisfaction, if chosen wisely. Great block machine work won't really make the car any faster, but poorly done block work can sure create an unreliable, short-lived piece of garbage. Good head work is the difference between a car that runs the same as everybody else's otherwise same car, and the one that walks off and leaves the others, lasts longer, and gets better gas mileage doing it.

 

I like what I am reading. By the way I do have the H.O. motor in my car. I was thinking the "kits that summit and others sell were just a little easier, but I do understand what u are saying. I wasn't looking for the cheapist parts, I was looking for parts that are good and cheap;-). I guess I can't have it both ways. I liike the input. As u prolly already guess I am a novist. I have never had a project car before. I have worked on my cars all my life but I have never gone this far. I want to do it myself. I have a lot of people who are helping but none of them have f-bodys. thats why I like this site. Can u tell me what I should be paying for my machine work on the block. I have no idea what the going rate is on the job. I am not porting just going .30 over. Thanks guys for all the info and help.

 

Does any one have an idea of a good Cam for my car. I want to go a little more aggressive but with out rough idle and gas milage.Thanks again guys

 

Assuming you have the 7004r transmission (you say 700f?) in the info to the right, youre going to want to pay attention to stall speed. If the engine is out, depending on how couragous you feel, you may feel the urge to bump up the stall speed a hare. However, this is not entirely necissary.

Assuming stock stall for now, unless you want to to the retro-roller setup, which in the end would probably cost you more than the budget engine build, i would suggest staying with the hydraulic flat tappet design. If the stock stall is used, a cam like the Xe262h or possibly the Xe268h could be used. Keep in mind, any cam used will act a tad bit 'larger; in a 305 than the 350. With either of those cams you will have more power than stock, yet you will have a fairly decent idle quality. both cams should pull enough vacuum to operate the vacuum accessories, i.e. brakes. if you are going to rebuild the heads, which i would suggest, i would get new valve springs and associated hardware as well. If you dont feel like mixing and matching components, Comp offeres their "k kits" which include the timing set, camshaft, lifters, springs, retainers, locks, and valve seals. They also include a tube of assembly lube. If i recall, the K kit for the 262 or 268 was around $350. The nice thing about the kit is everything has been matched from Comp cams for you. you just make sure theres proper clearance issues (although, with either of those two camshafts, i doubt clearance will present much of an issue). The only thing you would need are possibly pushrods and rocker arms. You might be able to reuse your pushrods. If youre not using guideplates, a budget part is the Melling replacement pushrod. I believe they are .99c each. Comp also sells a set that has been hardeded for use with guideplates and retails at around $30. Rocker arms pose another interesting issue. The factory rubber rockers arent the best, as we all know. Aluminum rockers are cheap yes. However their fatigue/stress rating is very low and early failure has been documented by several members. Some have failed as early as 30,000 miles. Comp, again, offers a very good alternative. They offer Magnum rocker arms. Not to be confused with their Pro Magnum series, the Magnums are simply a roller tip, rather than the full roller fulcrum design, such as the Pro Magnums. These are around $150 or so for the 1.5 ratio rockers for the 3/8" studs.

fabrication wise, another option is the LT1 camshaft. However, the LT1 cam is a factory roller design and would require either machining to the block to allow useage of factory roller parts or the use of retro fit roller lifters with the link bar design. They also utilize the 87-up factory roller timing set design due to the cam retainer plate. but the specs on the cam are about right.

Porting is for the cylinder heads. Boring the cylinders over (.030" in your case) is for the block. Which brings me to another point. You most likely have the #416 casting cylinder heads. When port and or/bowl work is done, these heads have some very decent flow characteristics. If you have the skills and the time to do this, i would look into it. It is not 100% called for, just a nice way to accentuate the larger cam that you will adding to the cylinder head. It isnt very hard to do port work. Just go to a local machine shop, ask for some junk head and have at the ports and bowls to get yourself used to the motions and whatnot. Then, after the heads get back from the shop, if you send them there, have at them. F-BIRD'88 and Sitting Bull both have very good articles/data on 416 cylinder heads. Another thing is the factory studs. "pull out" design as dubbed by a few members here. If the heads go into the shop, you may want to consider looking into the price of having them replaced with 3/8" screw in studs. As you increase spring pressure, you increase the amount of force that is being applied to the rocker stud as the valve is lifting. Under certain circumstances this pressure can literally yank the the stud out of the head as they are merely pressed in. Although, with a cam like the 262 or 268 and the lifts and spring pressures they present, i dont think it would be the top of your concern. That all swings back to the question of what can you fit in your budget.

Sending the block in for details (checking the deck, boring out, etc) and sending the heads in at the same time is what i did with my little 355. I asked that the heads were done first and returned to me first. I worked on the heads while the block was in the shop. By time the block was returned to me, i was a good chunk into porting my own #416's. In combination with a decent cam, that would put a little bit of umph into your 305.

 

I LLLLLLLLLIke it. I liked that piece of info. I am learning as I go. I had an idea that some of this stuff needed to be done but I wasn't sure . You have confirmed what I have been looking at on summit. I was looking at those two cams. I just get concerned about my idle. I hate a rough idle vehicle especially when its only a 305. If it was a big block or even a high pro form 350 that would be ok. Anyways thats my opinion. does not mean anything. If it was up to me I would not have a budget on the job. Its the fact that I have 2 children and a wife to suport that keeps me on a budget. I know if I skimp on doing something or on a part I may pay for it in the end. Thats why I need the input so not to make the mistakes that some have made. Thanks again for the help.

 

I have been told if the spring and valves are not past the wear tollerancenes that I don't have to do head work. Its this true or is this a place to not try to save money. I have all the manuels and they all specifiy a wear tolerance and if they are ok then making sure the head is not warped is the only concern. I am looking another $400.00 in parts and labor if i have the heads done. Do i really need to revamp the heads if the are showing good wear specs?

 

head work and valve springs are two very different things. Although, they are tied together in many ways. it is possible to upgrade springs without touching the factory guide bosses or the spring pocket (two things that are generally referred to when 'head work' and 'valve springs' are mentioned together). There are many valve springs that are designed to be able to fit into the stock valve spring pocket (aka - direct replacement part). I know that the Comp 981 valve springs are designed as such. There are also springs offered by various other companies that can fit the factory valve spring seat.

With the valve springs, i am assuming you have the factory springs. If so, it isnt a matter of wear and tear (well it is, although thats not the biggest of concerns, assuming they are still reasonable), its more a matter of the spring being able to keep the valve planted to the seat once the valve shuts when the engine is in higher RPM. Is what happens is the engine is rotating at such a speed that the valves are closing with such velocity that the springs no longer possess the strength to hold them shut once they close. The valve will litterally bounce back open for a split second. This is called "valve float." Seat pressure or the amount of spring pressure present when the valve is shut is directly related to valve float. The less pressure, the easier it is for valve float to occur. If you have the factory springs, you have roughly 85 or so lbs of seat pressure. That isnt very much. If they are worn even in the least, you will naturally have even less. Most aftermarket springs, even the factory replacement ones (i.e. "Z28 springs") have at least 100 lbs of seat pressure. Some can go a bit higher. But you dont want to much, since it is hydraulic and collapsing a lifter is possible.

The other thing about factory equipent is the guide boss to retainer clearance. On factory setups, you are allotted around .480" of lift or so before the retainer comes into contact with the guide boss. The actual number is often times a it less because of the general practice to leave about .060" of clearance space. So, while the issue of factory springs isnt really based on are they in good condition verified by a rimac tester, is more or less do they have sufficent seat pressure to control the valve at higher RPMs and prevent valve float? And is there enough clearance between the guide boss and retainer? Besides, the 981 springs are only like $55 at Summit.

Like i said above, get the K-kit that corresponds with the cam you are desiring and get valve springs that have been matched to the cam. If you get the 262h or 268h, that will probably mean 981 springs.

 

Heads are where power comes from. There's ALOT more to them than just replacing stuff that's worn out. They will make the difference between a motor that's no better than it was when new, or one that outruns the original by 20% or more, essentially without any penalty (gas mileage, driveability, reliability, longevity, or anything else).

The springs especially are worn out. They were inadequate by anything other than mass-production standards when they were brand new, and they haven't improved since then. The valves may be OK to re-use, but again, for less than $150 a set, there's HUGE improvements available.

The worst thing about doing work to a set of heads, is that it tends to really pile up. Most of it will end up being labor. You can easily spend close to $1000 working up a set of stock heads. That's carrying everything to the extreme of course. But, you won't get the benefit of your motor rebuild without doing at least some of it; and about the worst thing you can do is to just trade them in as cores for a set at the parts store.

As part of a rebuild, you'll be buying a cam; instead of getting just the cam, get the kit with cam, lifters, timing set, valve springs, retainers, and keepers. It's far cheaper than buying all the parts separately. Each of those Comp cams is available that way, from Comp. Another thing that goes on top of them, but isn't really part of them, is the rocker arms; the stock ones might as well be rubber, they are so poor at transferring cam motion to valve motion. Again, Comp makes a relatively low $$$ rocker arm that is a vast improvement, their 1400 series of part #s ("Magnum" rockers).

The heads you have, with screw-in studs and guide plates; 1.94" intake valves (installed as part of the valve job) and stock size (1.5") exhaust valves from Manley; port work that you can perform; and the XE262 cam kit, with the 1406 rockers, would be a good target for a budget build-up. Don't waste any money on a bunch of stupid chrome crap or things like that that will do nothing but lighten your wallet and cause unforeseen problems, just focus on things that make the motor run better and last longer.

 

RB, i think you mean the 1416 rocker arms. To my knowledge, 1406 is the 600 cfm edelbrock carb with elec choke, not a rocker arm.

<A HREF="http://store.summitracing.com/partdetail.asp?part=CCA%2D1416%2D16"> These rocker arms</A> are the ones that i believe RB is suggesting.

 

I thank you for your info. I had this pit in my stomach when I thought of not updating my heads. I have seen so much talk here and there in different threads of the stock springs and rockers being crap. I am feeling the crunch of the rebuild and when I feel that crunch, I get cheap and I have to lean to keep myself in check. Thanks for the info on F-Bird"88"'s and Sittingbulls head porting. I have the tools but I did not think it would be that easy. Well those two make it sound easy. I think I can do most of the head rebuild myself. I have a machanic friend who has blessed me with his tools and his time if needed. I don't know if any ones else has felt this way but I want to do almost all the work on this car myself. It is my first project car all tho I have owned the car for 12 years. I want to say when its done that "I did all the work." I have alot of guys giving me advise and most of it is good but none of them have 3rd Gen. I really like this site! I am going to my summit mag after I get off here. its time to start odering some stuff... little by little. If any one has a tips please feel free to chew my ear off tell me. Thanks again guys for all the tips.

P.s. I just thougth of something... If you guys keep giving the excellent advise that you guys do to all f-body owners are cars will never be classic due to to many on the road still.

 

You are correct on the rocker number, I must have got a brain cramp right then or something.

Head porting is one of those things that is near free in terms of parts & materials (especially if you already have an air comrpessor), you can't see from the outside, it doesn't diminish the value or originality of your car in any way except for racing it in certain "stock head" classes where you can't touch the casting, it gives you power without costing you gas mileage or driveability, and it allows you the builder to actually improve on the parts you have, instead of merely being an assembler. I highly recommend it to anyone who has their heads off.

IMO it really is easy, although maybe not the first time. I'd suggest getting yourself a junk head similar to your own to practice on a bit before you tackle your own, just to get a feel for the tools and techniques, especially if you've never done anything similar before. With just a little bit of thought and patience, you can get at least 80% of the gains that the best head porter in the world could get out of the same castings.

Remember you're trying to improve flow, and the best way to do that is NOT by "hogging out" the ports; but rather, what you want to do is to shape them so that the air has the easiest possible time getting through them. The places to concentrate on are where the air actually goes; you can shoot water into the port with a garden hose and see exactly where you need to work, and watch the results as you go, if you want to.

Here's a set I did recently. These aren't stock heads; but look at the streamlining around the guides, the shape of the bowls (especially the roof of the bowls where flow is highest, things like that. These are 200cc ports, and I doubt they're over 205cc after all this work. I didn't take off much metal at all.

 

Yup, a few more tips regarding DIY porting:

As RB suggested, go to your local machine shop and ask if they hav any junked heads that cant be used any more. When i asked for mine, i got a head that head a messed up combustion chamber and couldnt be used. They other chambers were fine. Got it for free. Practice on that head. Get an assortment of carbide bits. Some short shank ones and some 6" shank ones. I have them in the shapes of trees, cylinders, eggs, and cylinders.

When you do one port set (both intake and exhaust of one chamber) get some paper and make a lay out of the port. Then, you can use that lay out and make the rest of the ports the same. You should have the 416 heads on your car. So youve got a great set of heads to work with. Again, as RB stated, you dont want to just remove matieral from the port at random. Rather, you want to give the incoming air charge the easiest, most unrestricted flow path possible. I actually did take the garden hose and spray through the ports. Although, for me, it was simply to clean the ports out. For me, a lot of the port work was just behind the valve, where the port turns and leads to the chamber. Taking material off the guides, working the short side radius, blending the port walls, etc.

When you are done with the ports, you want to leave a rough surface on the intake side (dont actually polish them to a mirror finish). Polish the combustion chamber and the exaust ports.

<A HREF="http://www.sa-motorsports.com/portdiy/diyport.pdf">Heres a great link ro some great instructions</A>

 

so are you saying that its a better idea to buy the indivdual parts sperately even thought it will probabbly cost more? i.e. buy the pistons, then the bearings, the the gaskets.... like that?

 

Like ede stated. there is no such thing as a true "kit." They are selected parts, compiled into a collection and sold as such. A so-called kit has its advantages and disatvanges. With a rebuild kit (using summit's as an exampe), you (in most cases) get pistons (either hypereutectic or forged in some cases), rings, bearings, gasket kit, freeze plugs, high volume oil pump, plastigauge, and assembly lube. While in itself thats a good deal, it limits you to the amount of 'customization' you can do with those parts. Take for example, my rebuild. I looked at the various kits thinking they were a good deal. Then i decided i wanted forged pistons. So i looked at the kit with forged pistons. Well the compression ratio did not look right. And i wanted a Melling M55 oil pump, not a Speed Pro high volume. I wanted a 1 piece gasket, and the list went on. So, as you can see, you have limited flexibility when it comes to the actual selection of parts. now if, per say, the pistons in the desired kit suite your fancy, then sure, it may be the best option out there. It would all depend on what approach you wish to take and the amount of control you want over what parts go ito your engine. If you are like me, you want to select every last part individually. I guess it would also boil down to what type of rebuild you plan. If this is a daily driver, with no performance aspect intended, then sure, theres nothing wrong with hypereutectic pistons and a Fel-Pro gasket kit and whatnot. heck, hyper pistons can take a bit of power. But, if you want total piece of mind in your pistons like me, you want forged. In one of summits kits, they offer their Power Forged pistons, about a 9.72 with 64cc chambers, IIRC. I believe that kit retails about $350 and goes up, depending on if the engine is bored over and/or the crank has been ground.

For a good budget rebuild, here is just a suggestion:

-take the block and crank in to the shop to get worked.
-get a summit rebuild kit with desired pistons (get the appropriate bore and main/rod sizes according to machine work)
-re-use the factory crank and rods, get ARP rod bolts
-have the bottom end balanced (as needed)
-get a comp cams "k kit" with desired camshaft
-get the heads worked on, spring pockets cut to size of springs included in the K kit
-do some home porting on the heads, cut for 1.94/1.6 valves (assumptions made with 305 heads)

Of course there are small details that go with them, but thats the basic rebuild on a budget as i see it.

but before you select any rebuild kit, sit down and determine what you want out of your engine. Things like what type of usage the motor will see, what compression ratio are you shooting for, what type of pistons, things like that. Then sit down and look at the kits and find something that suits your needs. If so, sure get it, if not, perhaps look elsewhere. Keep in mind, Summit and Jegs are not the only parts distributors. There are several more that you should look into. Basically, look over ALL your options and desires. Then find parts to suit your needs.

 

i think so because of the parts i want to use. such as a one piece oil pan gasket. usually don't see that in a kit. m55 oil pump, arp one piece oil pump drive shaft. i won't use clevite bearings. for me it's just as easy to buy whatever piece i want from where ever i want. i usually don't worry about price. since most places are close in price to stay in line with everyone else. i usually buy from jegs for most stuff and a couple of local parts stores.

 

I don't want a high proforamance motor. I Know excatly what your saying. I looked into making some serious mods to my 305 and found that I can only do so much with a 305. It did not matter to much to me so I decided to go mild mods and I have been looking at the kits in summit and I think thats what I am going to go with. I have search the web big time and have a hard time finding what I am looking for. Some kits will give u hyper. or forged pistons and then a cheap oil pump or cheap gasket kit. I did look into upgrading the kits but the price went up fast when I tried that. Summits seems to be the closest.

Stekman, u listed ARP rod bolts... I am taking it, that I have to change rod bolts on this job? If so this is info I was unaware of. Can u tell me if there is any other bolts I HAVE to replace. Also u said have the bottom end ballanced are u taking about the rods?. Sorry I am out of touch with the lingo. Thanks for the info it might have saved me from rod bolt failure and for all practcial purpoes a complete failure. I don't want to make any mistakes on this rebuild. Thanks again for the input ...I can use all I can get

 

replacing rod bolts is a smart thing to do. it'll require you to have the rods resized. no other bolts really need to be replaced. when i build an engine i go to the tractor supply and buy up a sack full of grade 8 bolts for all the external parts and trash the originals. cost is 3.99 a pound and usually totals less than 20 dollars and i don't have to clean up any old bolts.

 

If I port my heads myself will I have to go to the 1.6 valvles or is that a stock size?. What are the stock sizes for my 416 heads. does porting my heads change any sizes of things in the head?

 

1.6 is the rocker ratio, actaully also a stcok valve size but i tihnk you're confused between rockers and valves. porting has nbothing to do with what sive valve is in the head. all porting does is remove metal from the ports allowing for more flow volumn.

 

One other thing, I didn't see it mentioned, the 305 crank and rods are dimensionally the same, but are weighted different for the (lighter) 305 pistons. You could use them, and you might justify that by claiming that a lighter internal assembly will aid acceleration, but you will have to have it balanced to the 350 pistons.
Try this place for cheap parts.
http://www.midwestmotorsportsinc.com...Assemblies.htm
Also, there have been occaisions where going to 1.6 rockers have caused interference with the pushrods/head clearance. There seems to be no problems unless the heads or block have cut, at that point, depending on your heads, the pushrods can interfere with the guide slots.

 

Stock valve size for 416 heads is 1.84" intake and 1.5" exhaust. They can be sized for up to 2.02/1.6, however i would not suggest taking them any larger than 1.94/1.6.

Factory rocker ratio is 1.5, actually, sometimes a little less. Upgrading to 1.6 ratio brings the pushrod closer to the rocker stud than a 1.5 rocker would. So as blacksheep stated, elongating the pushrod slot may be needed, but a simple file and a drill can take care of that.

 

[QUOTE]Originally posted by Stekman
[
For a good budget rebuild, here is just a suggestion:

-take the block and crank in to the shop to get worked.
-get a summit rebuild kit with desired pistons (get the appropriate bore and main/rod sizes according to machine work)
-re-use the factory crank and rods, get ARP rod bolts
-have the bottom end balanced (as needed)
-get a comp cams "k kit" with desired camshaft
-get the heads worked on, spring pockets cut to size of springs included in the K kit Of course there are small details that go with them, but thats the basic rebuild on a budget as i see it.
-do some home porting on the heads, cut for 1.94/1.6 valves (assumptions made with 305 heads)

ede, I am confused in what I read in blue above I misunderstood what stekman was saying. If I do port does that change any thing with changing the components of my heads?

 

I think that you'll have a problem with valve shrouding if you use 1.94 intakes. That's not to say you won't see some improvement but not as much as with an engine with a larger bore. What happens is that the bore covers (or at least comes very close to) the valve so it's not as efficient. Back in the day, on(some) big blocks the factory actually had valve reliefs cut into the top of the bore to help this. You might try that, but don't invade the gasket area, and for sure don't go below the ring area. Just be conservative, and try to make them all alike.
Somewhere around here somebody had a good illustration of this but I can't find it in the tech articles.
I'm also kind of wondering if he has heads that have smaller intakes. The L69 has 1.84 but I just don't remember if the LG4 (or others) are different.
Another thing, if you change the rod bolts, you're gonna have to rebuild the rods. If you aren't having a rod problem in the engine currently, you may want to keep the stock rods/bolts together and just run them as-is. I know there are better ways to do this, but at some point (being a 305) you're going to come to a point of diminishing returns.

 

I was looking at that in the summit magazine and I was looking at one of the kits (cca-k12-206-2) and it (the magazine) say that for that kit you need a stall converter that is 5-600 rpm above stock. my questions are: what is the stock converter stall speed, and would this be a good kit for an Lo5?

again I don't mean to hijack your thread, I just have about the same questions you do.

 

I am not ede, but perhaps i can explain myself better.

When you do porting, you are removing material away from the heads, in areas other than the valves. This includes the ports themselves and the combustion chamber. You remove metal from the guide bosses inside the ports, but you do not physically alter the size or length of the guide boss. You deshroud the valve area (opening up for larger valves) but do not physically alter the hole that is for the valve itself. You can enlarge the port entrances, but that doesnt effect much.

By deshrouding the valve area, that allows you to go to a machine shop and have the valve holes cut for larger valves. In your case, jumping from a 1.84" diameter intake and a 1.5" diameter exhaust, up to a 1.94" intake and 1.6" exhaust. Changing the diameter of the valve head is the only thing that is accomplished. Valve length remains the same as does the valve stem diameter.

Basically, porting does not alter what parts are needed. It can allow for different parts to be used, yes, but basically when you port heads, you are increasing the amount of air that can pass through a single port, whether it be an intake or exhaust.
If this is for use with stock heads, i would look into a dual pattern camshaft suc as the Xtreme Energy series. Any cam up to the Xe268h can be used on a stock stall. This is not to mean that a higher stall won't benefit, because it will. But they can be used on the stock converter.

The advantage of dual pattern cams over single pattern cams is this: We all know how lousy stock heads flow on the exhaust side. by keeping the exhaust valve open longer than the intake, you are, in a way, compensating for the poor exhaust flow. The longer duration gives more time for the exhaust gas to exit via the poor flowing port.

You might want to consider swapping out the cylinder heads. If yours are still the L05 heads, you have the imfamous "swirl port" design. In itself they are a great design...if low end economy and torque is what you need. however, anything above about 3000 RPM or so, and the little ramps that are cast in to "swirl" the intake charge act as nothing more than a flow impediment.
to my knowledge, all of the earlier 305 heads, 416's, 601's, 187's, etc, were all equipped with roughly 58cc chambers, and 1.84/1.5 valves.

 

Thanks Stekman I understand now. It takes a little to ink in but I got it now. I am going to port my own heads. Summit sells a porting kit but does not have the metel cutting bits. Can i still port using this kit or will i have to get the metal cutters. One od the threads has a complete write up on this and the kit used did not have the metal cutters.
Also I took the bottom out of my 305 today and everything looks really good Althought the main bearing in the back of the motor is groved in the center. What would cause this and do I have to do anything to correct it?

 

Carbide cutters (the metal cutting bits are a VERY handy tool to cut. It would take an extremely long time to port out some heads with stone bits and sanding rolls. Im sure you could do with out them, however, it defies logic to even attempt. i prefer to have an assortment of carbide bits in various lengths and head designs. I have them ranging from about 2" to 6" in over all length. I have the round heads, tree-shaped heads, cylinder heads, and a few others. They really make work easy. For the price versus amount of work they save, you will thank yourself in the end. I finish the ports out with grinding stones and sanding rolls/flapper wheels.

If you have a groove in the bearing, that indicates that there is/was something, usually a small chunk of metal, in the oil. It got wedged betweem the crank and the bearing and, as the crankshaft spun, wore a groove in the bearing. Degrease the block thouroughly, machine it if it needs, just make sure that every last bit of metal/gunk is out of the engine. If you have the means, taking the block to the local coin wash and spraying it out/down then drying it with compressed air is a very good method. Inspect the crankshaft. Make sure it didnt get grooved at all. If it did, it needs to be ground down (where they remove metal from the journals, i.e. smaller journal size). Any complete rebuild should include new bearings all around so the bad bearing, and the rest, for that matter, will end up getting replaced. Just make sure there is no coinciding damage on the crankshaft.

Basically, all you can do is to thouroughly clean the block and seal the passages as it sits. i coated my block in some oil and stuffed a trash bag over it. If the block is going to sit for a bit after it gets freshend up, do everything in your ability to keep foreign matter out of it. When its getting assembled, i taped over the passages. and plugged the holes. The damage has been done at this point, so the best you can do is erase the evidence by machining the crank if needed and getting new bearings. i cannot emphasize enough the importance of thouroughly cleaning the block.

 

I will get some carbit bits also.
I am having the block machined and bored .03 over so they will hot tank it any way. My crank saw no damage which I thought wierd because of the gouges in the bearing. I planned on replacing then any ways but I wanted to make sure I did not have a bigger problem. It was only the one bearing the rest look spotless. I am going to have them check the crank anyways to make sure. I not sure if I have to. Will damage be obvious? or will it have to be mic to be sure? anyways question like these are allways coming up. This is my first total rebuild and I am going very slow so I dont make any mistakes.
I have go more info off this site than any where else including manuals. Its the tipps that you peple give that really save a motor not the obvious stuff. I have listened to everything that people have told me so far except............... rebuilding a 305 Instead of going with a 350. This I feel there is not room for arguement.

Thanks guys for all the help ps. your not done with me yet

 

[Quote by Stekman}
[QUOTE] Take for example, my rebuild. I looked at the various kits thinking they were a good deal. Then i decided i wanted forged pistons. So i looked at the kit with forged pistons. Well the compression ratio did not look right. {QUOTE}

I have been reviewing this thread and noticed what stekman had said. I am looking at buying engine "kit" from summit But the hyper... pistons listed had a lower compression ratio than I have now with my stock Pistons. So being inqusitive person I am I called Summut tech. They told me because of the 58cc heads I have on my car that the ratio wouold be 9.5 (same as i have now). Not that i don't trust the guy Which I don't(money involved) CAn any one tell me if this is correct the pistons listed witha 64cc head have a 8.3 compression ratio. If that helps please let me know before I make a mistake

 

Sounds about right to me, maybe on the high side. If it's 8.3 with 64cc, i would give it maybe 1/2 to 1(maybe) point more with the 58cc chambers.

What pistons are these? Have a part number by any chance?

Hehe, They're hypereutectic.

 

Thats easy for u to spell. U knew what I ment Right I guess a few grunts and groans would have done the same.

Anyways part number STL- H534CP30 for the pistons also check out the kit too and tell me if it is ok
Part number FEM-MHP-124-300
both are from summit

 

My math is getting about 9.2:1 comression ratio. Since youve worked your heads over, it may end up being closer to 9:1.

Not sure you will need the HV pump. You could probably get away with the Melling M-55 pump with the 55-S screen.

It comes with plastiguage. Ignore that stuff. Get some feeler gauges and go in there and get accurate measurements.

Other than that, the components look pretty good.

 

If i am losing CPR than I am losing horse power ? correct? I am going back wards than. How can i go forwards? is that fact that i am going .30 over on the pistons help anything? Different pistons help.. I can not go forged they are way over kill for my motor. The pistons that are stock have a 9.5.1 ratio why do the hyper%$#%&* make my ratio go down I am very confused

 

Compression ratio is not set in stone. It merely is a ratio of total compressable volume compared to the volume when compressed.

Your L69 has flat top pistons with 4 valve reliefs. The pistons in the package are similar, flat top, 4 valve reliefs. There is no rule that a valve relief must be a certain cc (any material REMOVED from the piston is expressed in negative cc's) Some pistons have -5cc's, some have -6. The more cc's that are taken out, the more you add to the volume when compressed. This lessens the overal ratio, which in turn, lessens the compression ratio. Also, your cylinder heads, as cast, are ~58cc. Since you have worked them over, not sure what you've done to the actual chambers, but any material removed there also lowers the compression ratio a tad. Also, keep in mind that is more or less the static compression ratio. The dynamic is the far more important ratio to be concerned with. Cylinder pressure makes the power, not the static compression ratio. And cylinder pressure is what you get with the dynamic or the effective compression ratio. Valve timing is everything. Dynamic CR is taken after the intake valve closes. The intake valve will bleed off a bit of pressure as it closes. This is why degreeing a cam can be so important to fine tune an engine. Static is nothing more than a figure, a comparison between 2 values.

On a side note, a drop of like .2 or .3 in compression will easily be overcome by the fact that you have worked over heads. I wouldn't lose sleep over it.

On that note, i go to bed now.