[arush71]

Does anyone know the maximum valve lift on a stock 351C with early 63cc quenched 4V heads and flat top 1 eyebrow pistons ? 1.73 Rocker ratio.

 

[scottford351]

It is not the max lift that causes the problem. The intake duration @ .050 and centerline are the big culprit.

I have used [email protected] .050 with 106 centerline and had plenty of room. How big was you thinking of going?

 

[tonys10sec306]

i would stay with something around 520 lift

 

[1 Bad 88 GT]

Huh? So I must have a problem with my .528" cam?

 

[MACH72]

My engine had plenty of room with .540"/.560" lift. 226/235 @ .050", 111 lsa, installed at 106 centerline. Good luck, Tom

 

[cmf60]

Under .550" you are highly unlikely to have any problems. The over-lap area is where the problem occurs, where the piston is chasing the closing exhaust valve and the intake is just opening....its a very small area, perhaps 5-10 degrees of crank rotation. Ramp rates play a major part ofcourse.
If you're swapping out a cam, you have the intake off anyway and its a simple matter to pull the springs off one cylinder (you should probably change them anyway), put some light ones on, put some solid lifters (or make acouple of your old lifters solid) on that cylinder and check it. Just push down on the valve/s as you are approaching the overlap area and measure the clearance....turn enine alittle more and recheck etc etc.
Worth it for piece of mind I think, I remember my younger days and swapping out cams......cross your fingers, start it and quickly check for rattles!! We had no "crashes" but it was abit stupid....


<font size=-1>[ This Message was edited by: cmf60 on 4/8/06 7:27am ]</font>

 

[urban chaos]

Does anyone know the limitations of the stock cleveland 2v heads? I am currently cam shopping and want to go as big as I can without major head work (converting to threaded rocker studs).

 

[DanH]

2V or 4V , read the the old post you dug up . same for your heads

 

[Smits]

Looking to rebuild a 351C HO 1972-1973

I will get a 408 stroker kit will forged pistons 4.030" bore and 4.000" stroke and forged rods.
Will then have the std. heads (as they have a really good flow) (head info below)
machined to 60cc for compression 11.3:1.
I will then use comp cam part no. 32-772-9 [5]
Solid roller cam
RPM: 3000-7000
Valve timing 0.015
lobe center: 110
intake centerline: 106
valve lash: intake: 0.02 exh. 0.02
Duration: intake: 308 exh: 308
Duration " .050" lift: intake: 262 exh: 262
Valve lift: intake: 0.651 exh: 0.651
Lobe lift: intake: 0.383 exh: 0.383

My question is now will this camshaft fit my engine or is the lift to high?

Also have the edelbrock intake with a Holley 800 cfm carb.
MSD 6AL ignition control with performance distributor.

The engine will be used for sunday and some street/strip
I have access to unleaded 99 here in Denmark...

351C-4V
Engine and Years Casting No. Chamber Size Valve Size, Int/Exh Port Size
High Output D2ZE-A 73-76 cc 2.19 in/1.71 in 2.50 in x 1.75 in, Int
2.00 in x 1.74 in, Exh

thks

 

[DanH]

you will know when you mock it up . if you want to hear yes --well -- do you have the time money to do a second one ?

 

[BrianS]

Will then have the std. heads...
machined to 60cc for compression 11.3:1.

Machining from 75 down to 60cc will require about .075 off an open chamber head...not recommended but a 408 stroker with flat tops will have 11.3:1. 60cc heads will be more like 13+:1. For the money you're investing I would get some closed chamber heads and use zero to +.005 deck, dished pistons.

Solid rollers can have longevity issues when used for extended street use. I think most people would recommend a 106-108LSA with 8-12 more [email protected] on the exhaust lobe.

As far as lift is concerned, can you tell me where the piston will be when the valve is at full lift? Think about it.