King Lear

I have a 383 stroker, 222/230 @.050 .509/.528 lift hydraulic roller camshaft, 11:1 CR, Edelborck Rpm Air Gap intake, Quick fuel 750PV carb, TH400 tranny, 3.23 gears, Hooker Super Comp Sidepipes. I currently have ProComp 64cc 190cc runner heads that are getting switched for Canfields. Should I go with the 65cc 197cc runner heads or the 65cc 220cc runner heads. I am leaning towards the 197cc since it gives me better lower end TQ but I am not commited. My CR will drop a bit to 10.8:1 on this change as well. Also I am going to go with the Harland Sharp 1.6 roller rockers and get rid of the 1.52 Magnum Comp Cams roller tips. Any suggestions from you builders & jobbers out there that have any experience with this set up let me know, thanks.
Rich

63mako

I would go with thw 197's also. With a hydraulic roller you will not need the 220 runners with a 383 and less port matching on the intake. Have you checked your dynamic compression ratio? With your relatively small duration cam and 11 to 1 static compression sounds like you could be on the brink of detonation. I would check it and if the heads aren't ordered yet you might want to bump up the chamber size.

King Lear

the dynamic by KB is 07.817, help me out:
my 64cc + volume = 73.1cc
FT KB pistons volume 5cc or 7cc with eagle 383 kit
deck clearance .016
head gasket bore 4.155
head gasket thickness .0400

Little Mouse

I don't see the need for aluminum 1.6 roller rockers and more
money for new pushrods on an engine with low valve spring
pressure hydraulic roller cam, spend the money somewhere
else.

GrandSportC3

I'd go with the 220 cc heads... More volume actually gives you more torque.. and the 220 cc heads will produce more torque and significantly more HP than the 197 cc heads..

I'd bet my money that if you'd dyno the engine with both sets of heads, the 220 cc heads will produce more power AND torque across the rpm band!!

King Lear

thanks

King Lear

thanks

73, Dark Blue 454

I violently agree with Grand above. In a 383 build the 220's would work great. I have AFR-195's in a 406 build and I wish I had gone bigger. Also, I love the "bigger head / smaller cam" theory. What doesn't work, is "bigger cam / smaller head" combo.

383's and 406's are big motors in a small package and I think it's almost impossible to put heads that are too big on these mills,..unless you're building for a dump truck.

My opinion.

gkull

You need to get gaskets for your bore size like 4.060 or even better 4.030 on a 4.030 bore size. Better sealing and no loss of compression. my 383 with 64cc heads .041 quench -5 cc flat tops works out to near 11.2 C/R

It then needs 236+ degrees of intake on cam to keep out of detonation.

GrandSportC3

I had 215 cc heads in my old pump gas 383 which would get me down the 1/4 mile in mid 11's at close to 120 mph and the car had so much torque that you could smoke the tires OFF IDLE at the street (with 255/60R15 BFG tires)... Volume is a good thing when it comes to power AND torque... Porting the intake and matching it to the gasket (as matching the heads) will add even more torque and power.

The only thing that you are sacrificing with bigger heads is fuel economy.. But if you are concerned with fuel economy, buying a C3 is not really a good idea

King Lear

No, I could care less about fuel economy, I was just going off the latest cylinder head testing article in CHP where the Trick Flow 195cc heads out did the Motown 220cc heads on a 383. In the article they said the 220cc heads were better suited for 400ci and up. I think I will go ahead and go with the 220cc heads. The 220cc heads have CNC machined 65cc chambers. The 197cc are as cast

gkull

King lear - I think that your kind of missing the point. Bigger CC with larger valves have the ability to move a cylinder full of air faster. At higher rpm lets say 7200 where each cylinder is firing at 3600 times per minute. That is 60 times each second. That only gives the cylinder a very short time to fill, so you need big cfm heads with cam durations long enough to fill the cylinder or power drops off rapidly as the rpm climbs.

Now you have a relatively wimpy cam with low duration and low lift. thowing on bigger heads that flow great out to .700 lift is not a consideration. You have to look at the CFM of the heads at your lift. The .200, .300, .400 CFM flow where your cam spends the most time.

If Motown 220 and Canfield 195 have nearly the same flow numbers at lower lifts the head with the least port CC volume will win every time.

Your cam is limiting you to 6200 or less rpm anyway. So IMO changing heads will not really do anything if that is your only change.

Little Mouse

Your cam is to mild to get any use out of a 220 runner. go with
the 195 head unless you plan to use a lot more cam in the future
or a 408/427 size engine.

King Lear

I will put in a bigger cam at a later date, but I will first need to get rid of the stock gears. All the cam in the world does me no good on th400 & stock gears. I highly doubt I ever go over .600 lift though. Just no use to on a street car IMO. Maybe if I was going to race, but I doubt that ever happens to my 72 Conv.

King Lear

yeah, but that is all I really want for my street car, if I was going to race then I would put in a bigger cam, gears, 3000+ converter. I will probably never turn more then 6500rpm on this car, at that rate I would be well over 100mph on the highway, where I live if you are over 100mph on I-75 your playing with death anyway.

73, Dark Blue 454

Some guy named "Grumpy" agrees with me (or I agree with him) regarding port size and camming (big head / small cam).

http://forums.hybridz.org/showthread.php?t=100261

LFZ

220 is overkill with that cam....probably yield less power than the 197cc.

King Lear

I spoke with John Fenton of Canfield. He basically told me the same as I thought. To go with anything bigger is a waste. He did say they come more out to be like a 192cc intake runner after measured not 195 or 197. I doubt I will ever go above a .600 lift and they flow pretty close together up until .500 lift and higher so I am going to get the 195cc. They are also designed to work with 210 to 240 degree cams and mine is right in the middle of that at 222/230.

63mako

He is right! And so is redshark! If you are under a .600 lift in a 383 with a Hydraulic roller cam and will never see over 6500 RPM a 195 is plenty. The thing some on here are not taking into account is that with your stock gear and combo you need port velocity to keep your fuel atomized especially at lower RPM. With lower port velocity (large runners) at low RPM (street engine NOT race use) your fuel drops out of suspension and can actally puddle in the intake. Atomized fuel burns cleaner and quicker giving you low end power needed with your gear and driving style. If your launching at 4000 RPM and running a solid roller race engine get the 220 heads. Those 195 CC heads will give your motor all the A/F it can handle up to 6500 RPM and do it more efficiently than the 220 heads at your working RPM's.EDIT: That is why your fuel economy will drop with a larger port head. Less efficient atomization. Check out this post:http://forums.corvetteforum.com/show....php?t=1608090

Gordonm

Well said here. The 197 heads are going to be enough with that cam and motor size.
As far as the big head small cam vs small head big cam I like the smaller head with the big cam. I run a fairly large solid flat tappet with a AFR 190 head and make 500 hp easy. My heads outflow a lot of 210 heads at the 500 lift level so my heads work well with my combo. Now if I had a large roller with 650 lift yes the bigger head would be worth it. You have to look at the whole combo and car setup rather than just slap some big heads on and expect to make usable HP.