Advanced cam timing

[GrandestMarquis]

Getting ready to do the timing chain and gears on stock 1983 GM. Gonna get the Comp Cams timing set from summit. My question is, on the bone stock motor, can I advance the cam timing the 4 degrees that the new cam gear allows?

Will valve to piston clearance be an issue and will cfi accept it?

[pantera77]

You could, but why would you?

[turbo2256b]

You could but probably wont do anything mabe make things worse. Ford would already messed with advancing and retarding cam a bit to dial in best results. I know as I involved in doing stuff like this with Ford on other engine programs.

[GrandestMarquis]

Well, I was under the impression that generally by advancing the cam timing you get more low end torque. Retarding it gives you more on the top end.

Also, I have read that on some of the ford emission era engines the stock cams are are actually machined to be 2 to 4 degrees retarded.

Thought maybe advancing it would give her a little more oomph on take off for zero $$.

[GrandestMarquis]

I agree but I sort of think ford was more concerned with emissions than performance. Hence the pitiful small block sitting under my hood

[gadget73]

p2v should be no problem. Making it later could pose problems on the exhaust side but having it start to open earlier should be OK. Benefits? No idea. Without detailed cam specs to know exactly when the valve events were and running it through a simulator its anyone's guess. It might make it better, it might make it worse. Honestly, as wheezy as those CFI motors are anyway, I don't think you've got much to lose on the top end.

[GrandestMarquis]

p2v should be no problem. Making it later could pose problems on the exhaust side but having it start to open earlier should be OK. Benefits? No idea. Without detailed cam specs to know exactly when the valve events were and running it through a simulator its anyone's guess. It might make it better, it might make it worse. Honestly, as wheezy as those CFI motors are anyway, I don't think you've got much to lose on the top end.

Yea, that was my thought. I think a 4 degree advance will lower the peak power range by around 400 rpm

[mrltd]

You want to move the powerband DOWN on a lopo? The peak torque is already like 1600 or 1800 rpm. All moving the cam timing around does is move your peak numbers around, it doesn't actually give you any more power.

[pantera77]

You want to move the powerband DOWN on a lopo? The peak torque is already like 1600 or 1800 rpm. All moving the cam timing around does is move your peak numbers around, it doesn't actually give you any more power.

That's what I was thinking...

You'd be shifting at 3500...

[GrandestMarquis]

it doesn't actually give you any more power.

I know I'm not gonna gain horse power or anything. I didnt know peak is already that low. 1600 rpm? Are you sure about that?

[turbo2256b]

Peak is perty low. Ford did away with retarded timing when they went to FI. The 460 was the worst retarded 8* from 72 or 73 untill it went FI then went back to strait up. Retarding 8* probably lost about 40 to 60 lbs of torq. 460 trucks had another issue was the exhaust used the same muffler that was used on the 302s like 1 7/8 guts.

[85crownHPP]

There is definitely no quick, easy, or cheap way to get get more power out of the dreaded EEC-III CFI...

[GrandestMarquis]

Thanks guys. Straight up it is then.