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I know I don't fit into this forum perfectly but I was still looking for some good advice. I'm rebuilding a 350 to put into my 63 Impala. +.030 w/ speed pro hyperuetectic pistons, all new bearings, and so fourth. I have a set of 76cc 441 GM heads. Although I know they're pretty good heads I was looking to upgrade. I want 64 cc so I don't have to go to a domed piston to get my compression ratio up to about 10:1. Does anyone have any suggestions. A few I had in mind were AFR's, World S/R Torquer, Dart Iron Eagle, and Edelbrock Performer and performer RPM heads. I plan on matching my cam to the heads. I want low end - midrange power. Any suggestions guys??

I have the same question Tech has why do you want to run that much compression. If this is going to be a street/strip car I can understand, bu if you going to be primarly driving it on the street a true 10.1 compression motor is not all that much fun on pump gas. Can you give us a few more details on how your going to be driving it and some other specifics like trans type gears etc??

It will be mostly street but I will definately be taking it to the track once and while. Right now it only has a power glide in it but I am in the process of getting ahold of a TH350. I plan on put some higher 3.?? gears in. I am an automotive technology student and I have an engine rebuilding class now. I figure I can get the engine built the way I want it, and worry about the rest later. I wanted to go for higher compression because I want it to be a pretty serious street motor. I wouldn't expect to put anything less than Sunoco 94 in it. 10:1 still to high?

Do you have any advice for the heads? Everyone claims to have so many horsepower gains, but you never know what else is done to the engine. I was wondering if anyone had any experience.

Any other suggestions or advice are very appreciated!
Thanks for your help so far.

If your serious about it then go with AFR heads or Canfield heads, i have only heard tons of good things about both, if your still looking to go the cheaper route, find some double hump heads, shave then down a little to about 62 cc and bump your compression up a little if you want. I dont think your gonna have many people on here to agree about high compression engines in street use. I run 10.84 :1 pistons with heads shaved to 62cc on 93 octane and have for 2 years now, i street and strip it with iron double hump heads and have had no problems. Look at this website, it may be helpful

http://www.chevytalk.com/tech/engine/SBC_Heads.html

Good luck and keep us updated.

I think Richard ment to post this here.........


techinspector1 ..........

"more reading on compression ratio...
http://www.clubhotrod.com/forums/sh...on+ratio+101%2A
http://www.clubhotrod.com/forums/sh...on+ratio+101%2A
The same combination , flat-tops, 4 cc's, 9 cc's but with 64 cc heads will yield 10.44:1 c.r. and if you do that, you'll probably need more cam to bleed off some of the compression. When you do that, you move the power up in the rpm range away from streetability. Take some advise from a geezer and build it 9:1".


I agree with Richard on his recommendations on a 9:1 compression motor.

Now not to throw stones at anybody, but when you have had a few years in the automotive field your going to find that what people tell you about their engines is sometimes a little misinformed. Compression ratio is a good example. People will buy as set of pistons with an advertised ratio of 10:1 or whatever, but have not read the fine print that compression is with a head of so many cc's and such and such a thickness of head gasket. They also assume that the combustion chamber on mass produced heads are actually what the manufacture claims (if your in the engine rebuilding portion of your course now, you are likely doing head cc'ing and balancing volumes and are finding that all is not as it's claimed to be.

Another important part of building your engine will be camshaft selection as Techinspector says. By now you should have gone through the difference between static compression ratios which is mathematically determined and effective compression ratios which involves factors such as cam timing, volumetric efficiency, air density etc. These are the factors that the engine will really have to live with in real life vs. what sounds good on paper. A good example of this was a 57 Dodge I had a few years ago, it was running a 10:1 compression 440 and did really good where I live (4500 feet) but when I went out of town, (lower altitudes) even with the best gas I could find I needed to back off the timing and performance went down the tubes.

Now most of the geezers here (according to streets I'm one of them ) have found out for ourselves some things that seem to hold true we did that by experimenting. Some of the things I have found are:

1. Running lower compression ( 9:1 for me) and decent timing makes more HP than higher compression and retarded timing.

2. You can run SLIGHTLY higher compression with aluminum heads (my experience is about 1/2 a point).

3. If it's a street driven motor, especially one that's going to be driven is cool weather a heat crossover is a GOOD thing. Personally I kick myself every morning for going with the Performer RPM heads (no heat crossover) instead of the Performer heads on my Mustang.

4. Carbureted engines are a lot more sensitive to altitude and air temp changes than EFI engines and can be a real bear if your running on the ragged edge of compression.

5. There is such a thing as too much, be it compression, cam, valve size etc (especially if your looking for low-mid range power).

At this point in your life I encourage you to experiment and find out for yourself!!!!! It's the way your going to learn and will make you a better Tech (it's called paying your dues). Good luck with your project and keep us posted on how it's going.

Thanks for your help everybody. I don't mind paying my dues and what not, but that calls for spending money that I don't have.

Anyone have any experience in using 58cc "896" chevy heads? planning on putting larger 1.94/1.50 valves in them.

63 Boat....your gonna pay your dues weather you like it or not, and it appears that it's gonna be sooner than later. The information you have already been given here is the best advise that you can get- it may not be what you wanted to hear but belive me- been there done that & paid my dues too.
Now- the 896 power packs are good heads, and they are heavy so that you can port the crap out of them....194/151's will flow good for a small block. 390's in the rear will hook & cook with that th350 tranny.
Don't over build the engine- you can get more out of gears & rears than you'll ever get from the mill....ask Nissan, Toyota, Honda.
Good luck with your project & let us know how you do....

I am no expert, but take a look at Pro Topline heads. Call Mike Bradley at Bradley Autoparts in North Carolina at 704-821-6234 tell him that Sean Hill refered you. He was very helpful with everything I wanted to know. Also go to the Pro topline web site and check out the flow numbers for their heads.

"Question to the board: Why is it that every new generation has to start from the ooze at the bottom of the pond?"

Are you kidding me? I am 19, taking 23 credits, and working 15 hours a week, and I'm trying to build a budget small block to get my car on the road. I have limited options here. I came for some suggestions and help and so far all I have gotten is a bunch of old heads who haven't proven to me that they know as much as they think they do and can't offer anything other that what SHOULD be done. with all of your "geezer" years of experience you should have a vast knowledge of these heads. I guess i'm supposed to know about all of this already?

I am not some pathetic kid who hasn't done his homework. Why would I waste my money when I can ask someone a question and get their feedback and use it in conjuction with the books upon books I have read about building these engines. I have read nothing about the 896 heads cracking, so how would I know?

I belong to other forums where ppl actually without starting arguements w/ every comment. This place is a joke

I thought I rode the fence pretty good there..I could already see that he was convinced as to what he was going to do, so why bother with trying to convince him that he was throwing his money away?
Richard you didn't even try telling him that the valve seats aren't hardened, and I figgered that he would find out all the other stuff as he went along..lol.
Sometimes ya just gotta let them eat cake, but nice try.

I think this falls in the territory of young bull runs down the hill old bull walks down.Young bull doesnt know hes missin out!!!

WHEN YOU SAID STREET/STRIP.you opened yourself wide open bro.......i have been racing a long time/along with friends,if you want a budget motor stay with a lower compression/heads and enjoy the 90/92 shit fuel.....once you start taking her to the strip,you start breaking things cuz you,like all, want to go faster, just enjoy the cruise and street,stay away from the strip,if you go with this car ,you are surely gonna break something....just my 2 cents. my 2 centz.......

Man you guys are great. I am a 26 today, and I can really appreciate the advice you just gave this kid. I am a kid myself and I have much to learn. I grew up in the "old school" with a bunch of back yard racers and shadetree mechanics, What I have come to learn in the past few years is that with all of those years of learning things from the "geezers" and reading all of the books I could get my hands on, didn't have anything on actually doing it the hard way and finding it out for yourself. Some people are just hard headed (like me).

Now maybe I can ask for some advice about heads. I have just put a set of 993 "race" heads, as the advertisement said, on my truck. They have 2.02/1.60 valves, 4 angle valve job, hardened retainers, guide plates and screw in studs. 170cc intake runers, 76cc combustion chambers. They are going on a fairly fresh 350 (27,000 miles) crate motor with "factory" flat tops. I have a .465/.488 lift cam with 292/300 duration already in the truck. I also have an aluminum edlebrock intake and a 600 edlebrock performer carb. Headers, 3in pipes and Flowmasters. I think that is everything.
Does anybody have a rough estimate of about how much horse power this motor should make?
Were the heads worth the $425.00 that I paid for them?

Any info that you can give me would be great. I am anxious to learn and this forum is the best place I have found yet to do just that.

Thanks

Hey, hey hey, I have been teaching the younger generation for 34 years and you have to create conditions so that they can "discover" things for themselves that others may already know. Anyway this problem comes up a lot on this Forum so all I can say is that there is a big generation gap and maybe it is aggravated by the nature of short terse messages? Anyway I suggest "Boat" take a look at the site on heads where flow values are given:

http://chevyhiperformance.com/techarticles/41598/

Since I last signed off on flatheads with seemingly simpler technology depending mostly on porting and relieving and choice of cam back in the '50s I too had a lot to learn about SBC heads. The sad facts are as mentioned above:

1. gas today is not what it was in 1965 and may get worse!

2. Pb additives are not in the gas and valve seats in old heads will recede using today's gas.

3. heads designed for 283s/327s using good gas are not optimized for more displacement in 350s/383s and poor gas.

Anyway I am a novice with regard to SBC heads but there is a wealth of information on the Internet (some of it advertising hype?) but here you can get some advice based on actual experience which ought to be more valuable (although sometimes these folks don't agree totally and the debate is educational). Anyway we should not discourage Boats. The problem with economic limitations is that you try to get the right combination the first time and that is not easy so experienced advice can save on expensive experiments.

Don Shillady
Retired Scientist/teen rodder