Hey everyone, I'm new to the forum and figured I'd try to expand my knowledge about high performance engine building. I just won a set of 327 62cc camel hump heads off of ebay and plan on rebuillding them and putting them on a 383 stroker engine that I also want to build later on. Is this a good idea? I'm thinking about domed pistons but read in another thread that the 461 casting camel humps have problems with domed pistons and spark plugs. So I'm not too sure about that yet. I tried to use the engine analyzer program but just ended up pulling my hair out!!!! Someone please enlighten me on this subject and give me any suggestions that you think will be useful. Justin
Well, I was gonna be objective but you haven't done an intro yet, so I have to smack you around a bit first. You wasted your money if you spent anything over $100. The cost of a quality rebuild on those heads will make them marginal against the value of almost any iron head available today. The latest vortec design, about $550 a pair new, is far better out of the box and any after market choice competes with them quite well. Some even flow better than the lower end aluminum parts. Now go do an intro and figure out how the search function works.
I spent $257 on the heads and plan on rebuilding them myself. An intro?? I'll work on one and post it ASAP! Justin
hi justin. welcome to the HAMB. the camel hump heads are not a bad head , and can be made to work rather well. I however would not use them as a head on a stroker motor. you are gonna have to figure in compression ratio...prolly gonna be a tad high on a 383 with 62cc chambers you are aloso gonna want to flow some air with the increase in cubes...I would not invest in a vortec style head, but would be looking for a DART 200 or the AFR 195 as possible choices save the camel humps for a nice 327 traditional build. Fred
By the time you do seats, guides, valves, springs, and machine work you'd better off with aftermarket heads. I'm doing a 383 right now with World Products SR Torquers. They're for a kinda conserative driver, so i want maximum torque from ground zero to about 4500 RPM. Anyway, if this is a "pump gas" motor, good luck. The long stroke, small chambers, and dome pistons, ain't gonna happen. You'd have to lose at least TWO of those factors. Then there's intake, camshaft, weight of vehicle, and rear gear ratio. Combined with what "purpose" are you trying to package? But, from what you've outlined so far, you're off to a bad start. Not trying to pop your bubble. It's fact.
Thanks Groucho for the information. I won't take offense to negative comments I'm here to learn afterall. I was thinking about running the engine on ethanol alcohol or 93 octane gasoline. It's just some ideas for the future. All I have now for sure is a set of heads that are coming in the mail!!
Well, if you're set on using them, consider a D-Cup piston instead of a dome for the 93 octane. I think a flat top will still be too high for even the 93 octane with that stroke. Ethanol, well, you can sure get away with almost anything. I guess you just need a plan and stick with it. Good luck.
461`s dome pistons on a 327 would be a great motor if you match the cam and everything else. Do you do machine work yourself? You`ll probably need to replace the guides, maybe hardened seats if they need it and a valve job. They will work on a 383 but you`ll nede to have them ported to flow enough air and by the time you sink all that money into them, you could have gone with the dart Iron eagle heads. put the 461`s on your 327 and you`ll be happy with that. when you build your 383 just expect to buy another set of heads but don`t waste your time with any GM production heads, think aftermarket. on a side note, there is a guy on another board I go to with a 383, flat tops, home ported 186 heads, just a newer version of the 461`s, and a comp 286 magnum and he`s running low 12`s in a 70 nova.
http://car.race-cars.net/calculators/compression_calculator.html Here's the link to the compression calculator I used. It says I should have about 6:1 compression with flat top pistons and 0.41 thick head gaskets on a 383 with 63 cc heads.
Yeah I plan on porting and polishing and assembliing the heads myself. The only thing I cannot do is put new seats, valve guides, and grind the valves and seats because I don't have the tools. I was thinking about a 327 too but the blocks are too hard to find around here.
wrong-wrong-wrong. Not the link, i haven't looked at that yet. But the 6-1 with flat-tops on a 383 SBC w/63 c.c. chambers. Try somewhere north of 10.5-1. Now, i'll look at your link
I havent had time to look at your link, but what figures did you put in it to get that compression? you are way low bore? stroke? compression height of piston?
I get 12.1 to 1 on that site 4.030 bore 3.750 stroke flat top .041 gasket thickness adding stock deck height to the equation still keeps it in the 11.6 to 1 nieghborhood
Bore: 4.030 Stroke: 3.75 Number of cylinders: 8 duh!! Piston dome: 0 Gasket thickness: 0.41 That's the values I put in the calculator
There's no replacement for displacement. By you porting the heads i'll assume you want power. Build the highest cubic inch motor you can for your budget. Better drivability as far as not needing as much rear gear would be one pretty worthwhile advantage. The bigger the inches, the milder the motor needs to be to acheive a certain goal.
64cc, 383 flat tops, zero deck height and a .041 thick head gasket will put you around 10.8-11.2:1 compression. alot higher than 6:1. you stated you plan to rebuild them yourself but then you don`t have the tools to do it so your going to have to pay a shop to do it and that isn`t cheap if you get quality work. I had nearly $1000 into a set of gm heads and that did`nt include the port job. also, if you don`t have a flowbench, porting heads yourself can actually hurt the flow of the heads and can hurt performance. I use to work at a machine shop that had a head porter when I was younger and he showed me alot of heads that people had done a "home port" to and they actually flowed less than a stock head because they just hogged them out and did`nt know what they were doing. for a home porter, just blennd the bowls and gasket match the intake and thats it. The 461 heads will work on a 350 as well and i know those are availalbe anywhere. What is your expectations for the motor? whats it in?
I plan on putting the engine in a late model s10 pickup truck and take it to the track every once and a while.
It took another look. I went with their "default" on the head gasket thickness without paying attention. It's almost a HALF INCH THICK at .42!! It needs a zero after the point. .042 instead of .42. Shame on me! At 11.9-1 i think it's still way off on the high side now
My uncle had a 69 stepside chevy with a 327 in it that had 64 cc camel hump heads that ran a quarter mile in 11 seconds. I'm going for mabye 10 seconds with a s10.
figure in the valve reliefs that your "flat tops" are going to have actual compression distance on the piston true deck height area above rings..etc. and its gonna be lower that is truly one of the more plain jane calculators I have seen
Yup. I think it's off a full point+. It says 11.9-1. I believe that combo's in the neighborhood of 10.5 or 10.9 to 1. I know there's lots of factors, but since we're being kinda vague and generic..........
Thats pretty good times for a heavy truck and a small motor. probably wasn`t too streetable. If your looking to go 10`s, then my suggestion is to sell those heads and go aftermarket. They will just eat up too much money and even with a pro port job they will never compare to a set of dart Iron eagles or similar heads. Try posting this on this site www.chevelles.com and post it in the perfromance section. Plenty of racers and professonal engine builders there that can help you put a combo together to get the times your looking for.
Uncle Bud's truck was his shop truck and daily driver. It had a powerdlide transmisson. He still has it but it has been parked for about 5 years because it started getting bad blow-by and he parked it and never rebuilt it. I didn't think that truck could make those times too until I saw it! Thanks for the link to the other forum ajs! I'll still post on this one too. I'm pretty sure I'll come up with a question that someone will scratch their heads over! lol
suspension and tires have alot to do with timeslips. an 8.5 rear and leaf springs won't go like the long arm coil spring chevy truck rear. heads, cam, torque converter, gear, it all has to work together.
I`m not calling you a liar but a 4000 lb truck with a 327/powrglide combo is hard to believe it runs 11`s and is a daily driver. I`ve built 327`s that ran low 12`s in chevelles and they are lighter than 67-72 chevy trucks and they need better trannys than the pg tranny. I don`t want to start anything so I`ll just say this, if you want to run 10`s, your 461`s won`t cut it. Even some out of the box aftermarket heads will run circles around the old fuelie heads.
I'm not taking offense ajs, a lot of people didn't believe this until they saw it. It was a daily driver but the idle was so damn rough, it made most people that drove it nuts because of the idle. I don't remember what kind of cam he had in it though.
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