hp and tq ?
Posting Guru
Joined: May 2003
Posts: 1,242
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From: Joliet, Illinois
If you were looking for high rpm horsepower, I'd get a set of 2bbl 351 Cleveland heads and make a second generation Boss 302 clone.
The first design used the 4bbl heads and they flowed way too much for 300 cid but are perfect for 350 cid!
If you were after all around power and have the cash, a set of after market heads like the Dart Windsors.
Add a decent cam and an appropriate intake, then you should be on the right track!
The first design used the 4bbl heads and they flowed way too much for 300 cid but are perfect for 350 cid!
If you were after all around power and have the cash, a set of after market heads like the Dart Windsors.
Add a decent cam and an appropriate intake, then you should be on the right track!
FTE Legend
Joined: Jun 2006
Posts: 31,930
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From: Ottawa, Ontario
That's the wrong approach IMO, buy a cam based on how it models with your engine combo in a program like desktop dyno, if it then turns out produce a choppy idle that's a bonus, but if not so what. Would you rather have a motor that sounds all badass but is a total pooch or one that sounds a little less conspicuous but hauls the mail?
Cargo Master
Joined: Dec 2004
Posts: 2,232
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From: NE Texas
Paul, as always, is right on the money here! The key is in the combination. Putting lots of cam to combine with limited flowing heads is not a good combination. Right now you have an engine that should make pretty darn good low and mid range torque for a short stroke engine. Camming it up will take away the bottom end without giving you much high RPM horsepower gain in return.
There is an advantage to small port, small valve heads. That advantage is good gas speed which improves low speed torque. This is, of course, at the expense of high speed horsepower. In scanning your list, it sounds like the engine is currently a low and midrange torquer. There's nothing wrong with that as far as fun driving goes.
Horsepower wins races, low speed torque makes it fun to drive. Take your pick.
My $0.02,
There is an advantage to small port, small valve heads. That advantage is good gas speed which improves low speed torque. This is, of course, at the expense of high speed horsepower. In scanning your list, it sounds like the engine is currently a low and midrange torquer. There's nothing wrong with that as far as fun driving goes.
Horsepower wins races, low speed torque makes it fun to drive. Take your pick.
My $0.02,
FTE Legend
Joined: Jun 2006
Posts: 31,930
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From: Ottawa, Ontario
Further to what Doc and I have said about building a package, here is the graph for the prediction I mentioned above. I am also showing another cam that I think is better overall for a street vehicle, it actually make slightly more HP everywhere except peak which is sill only down 3hp, but makes more TQ across the whole powerband and 20ft/lbs more at 2000rpm which is most significant. It's just a personal yardstick of mine but 300ft/lbs is my baseline for a street motor, below this and the motor feels weak from the drivers seat.. though in a relatively light car you can get away with a little less, but it won't feel sporty IMO. Comp cams recommends a 2000 stall converter for both these cams and says the idle is noticable but you can get away without a high stall with the 242 cam and that will translate into better fuel milage.
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Posting Guru
Joined: Mar 2010
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From: northern va
yeah i also would rather have power than sound i was just wondering if the cam i have or the comp cam you mentioned was going to lope good or if it would sound mild. i got the heads in the ups today and cant wait to get them on. i also got some arp head bolts what should i use for the outer head bolts to resist coolant teflon tape? the old bolts i reused before had some kind of sticky white paste on them. im starting to feel like im on to something with this motor and its going to be fun to drive. i see you said 2k stall when i got my crane cam it said 2500 so i was looking at the b&m holeshot (around 2300-2500) and what happens if i bump the carb cfm's up some like 650 or 750
Postmaster
Joined: Mar 2005
Posts: 2,949
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From: Earth
Don't use teflon tape on the lower bolts, use thread sealer.
No worries on the lifters.
The only worry with those heads is the quality of the valves/springs. I wouldn't push them with a super high-lift cam or repeated 6,500 rpm runs. Otherwise, they flow better than anything Ford ever put on a 302 (well, maybe not a Boss 302...) or 289 and plenty to get you to 350hp+. The 289HP engine spun 7,000+ with stock heads.
Go ahead and get a cam with ~230 degrees @.050". It will lope and it will make power, assuming you have the compression for it. In a street hottie with a 2,500 stall it will kick you in the crotch.
No worries on the lifters.
The only worry with those heads is the quality of the valves/springs. I wouldn't push them with a super high-lift cam or repeated 6,500 rpm runs. Otherwise, they flow better than anything Ford ever put on a 302 (well, maybe not a Boss 302...) or 289 and plenty to get you to 350hp+. The 289HP engine spun 7,000+ with stock heads.
Go ahead and get a cam with ~230 degrees @.050". It will lope and it will make power, assuming you have the compression for it. In a street hottie with a 2,500 stall it will kick you in the crotch.
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Posting Guru
Joined: Mar 2010
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From: northern va
yeah im going to get that comp cam 31-226-3 it has 230 at 50 . im looking at the comp cams ultra gold roller rockers, they also sell proform for about $100 less are they ok or should i go with a well known good part from comp and has anyone try to exchange parts with summit after having them for like a year but never used
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Posting Guru
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From: northern va
hey conanski do you think the 600 carb is best for my set up or should i go bigger. i know that most people have to big of a carb and it wont take a monster carb but am i holding mine back any? my carb is ok but like 8 years old and manual choke
Junior User
Joined: Mar 2010
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if your going to buy rockers get the comp magnums and be done with it forever.
i have had and seen more than a few sets of alum rockers roller tips eat into the body of the rocker due to the way the smooth body of the rocker sheds oil.
if they ever make a alm rocker with pressurized oiling to the roller tip it would be ok.
i have had and seen more than a few sets of alum rockers roller tips eat into the body of the rocker due to the way the smooth body of the rocker sheds oil.
if they ever make a alm rocker with pressurized oiling to the roller tip it would be ok.
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Posting Guru
Joined: Mar 2010
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From: northern va
i have the comp magnum roller tips but the heads say to run roller rockers so i figured full roller. they make stainless steel full rollers and i thought about them but i started looking at the comp cams ultra golds and they have life time warranty
Junior User
Joined: Mar 2010
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i didn't realize they made magnums in just roller tip.
i looked into it and i meant the pro magnum rockers
Pro Magnum Roller Rocker Arms http://www.compcams.com/information/.../ProMagnum.asp
i looked into it and i meant the pro magnum rockers
Pro Magnum Roller Rocker Arms http://www.compcams.com/information/.../ProMagnum.asp