ok,here's the deal.i got screwed on the purchace of a crate motor and got stuck with a 350 with 58cc heads and .040 over 32cc cast dished pistons. since then i have come up with a set of topline 64cc vortec heads and have put a comp xe274 in.the heads are new and have not been installed.
the original heads(601's)had a coil bind problem(i'm a dumba**!)and chewed up the top of several valves.my machinist thinks it would be a waste of $ to do a 385/388 build on this block due to cylinder wall thickness(as a point he has been 35 years in the performance business).i have not had the thickness checked yet as the shortblock is still assembled(engine hasn't been run since problem was found).
my question is,if i was to flush the crankcase and bolt the vortecs on at least the car would be on the road,if i used a .015 head gasket i would be at 8.0:1 comp ratio.i know it's not a performance ratio,but would i encounter any serious problems while building a serious shortblock?
also if i plan on keeping the vortec heads would it be worthwhile even going to a 385?or should i save the bucks,get my block done right,get a balance job,and stay with a 350(357?).
dam!i really miss driving my camaro!
Eric

I am curious how you are arriving at a 32cc dish. That is seriously huge. Any way you can post a pic of the pistons?

give me a few minutes,btw they are huge cups!
Eric

Install a chea, --er, a , -- "inexpensive" Summit cam and lifter set and run what you have until you can build correctly what you want.

Their 184/194 or 194/204 cams should work with that low a compression number if that is indeed what you have?

In fact the 194/204 is close to the great old stock, -929 cam that they still put in the Goodwrench engine if they haven't ran out of them and are using a newer, comparable, 305 cam..

And I haven't heard of that big a 350 dished piston either??

pdq67

http://www.camaros.net/cgi-bin/forum/ultimatebb.cgi?ubb=reply;f=4;t=008771

appologies :the last post didnt work

Eric, I sent you an e-mail. But to get everyone up to speed on the pics you sent me, those are indeed seriously dished pistons, made (I believe) by silvolite specifically for using 305 heads on a 350.

Personally, I think you'd loose low end going with the Vortecs if the compression ratio drops that much. I'd just fix what you have and see how it runs. That way, if you don't like it you aren't out much.

I don't know what you meant by "trashed valves" but OEM replacement valves aren't much cash and you could even get away with a shade tree job and just lap the new valves in where needed to get them to seal.

This way you could start accumulating the right parts to build this 383/385 that you want to. Just take your time and do it right and drive your 350 in the mean time.

JMO

i am with you eric,but basically all the moving parts on the heads(including the studs were destroyed,i wasnt sure about the retainers or locks but since some of the studs were cut pretty deep i tossed them all.i pulled the lifters tonight and saw visible scratches outside the contact area,is that normal?if i could fig.out how to post pics here i'd show you.
btw. some of the valves were mushroomed 0.2 over their stems.it figures,since i have been out of the game for about 20 years and forgot to remove the oil dripper cups from the springs!that may have given me the clearance i needed.
at the time i was in a hurry and forgot the first rule of engine building;Take your Time!
at the time this was my work car so i kind of had to rush,but now i have more time to do it right.hey,it still ran 3k miles and didn't falter!
anyone want some 601 (bare) heads?
Eric

Are you sure the visible scratches weren't just manufacturing "turning/machining" marks that have had a wear pattern worn over them, b/c on some lifters it is natural?

pdq67

Studs are cheap . . . so are valves, retainers, and locks if you aren't set on anything fancy. If you just want new heads go for it, but if the castings are OK it shouldn't be too bad just to do a repair.

i guess what i'm getting at eric,is that i could throw some flattops in there and use the vortecs(which i already have)and be on the road that way.i guess i'd rather do it right once than keep tearing down and rebuilding(the apartment mgr already looks at me funny!).guess the best thing would be to have the block sonic tested and go from there.i'll check out cheap head parts tomorrow and compare cost between them and pistons/rings.then i'm sure i'll still be undecided!

Well if you are going to throw some flat tops in there then by all means go with the Vortecs . . . they will make two full points more compression than the -30cc dish pistons that are in there now. In fact, be careful you don't go too high with flat tops . . .

With a -30cc piston, 0 deck, .041" thick head gasket and a 62cc chamber I get 8.1:1 static CR

With a -5cc piston, 0 deck, .041" thick head gasket and a 62cc chamber I get 10.5:1 compression.

I'd use a 4 relief flat top personally which should in theory put your CR closer to 9.75:1 (assuming the 4 reliefs are -12cc)

9.75 will make a DCR of 7.9:1 with the XE 274 cam. With 10.5:1 that DCR jumps up to 8.5:1 -- a little high IMO, with the -30cc pistons you are way down at 6.6:1 DCR.

I guess it all boils down to money and time . . . if you have the time and money to go with flat tops might as well go with the Vortecs --- if you are stuck with the -30cc pistons for now I'd just repair the 305 heads and save up for the 383 combo . . .

But that is just my opinion . . .

the topline vortecs are listed at 64cc as opposed to the fastburn aluminum's 62cc,but then comes the dilemma,if i,m gonna put forged pistons in anyway i might as well just save for the crank n rods(i have $ for either pistons or crank n rods now)and build what i was going to in the first place!since i'm not positive where the bore will end up maybe i should just go ahead and order the scat 9000 3.75"crank and 6"I-beam capscrew rods.after all two birds in the hand are worth four in the bush(if i did the math correctly).like i said i'd rather do it right once than keep wrenching around.
and btw i ALWAYS appreciate your opinions!
Eric