I have a question about my 460, but I think it applies to all engines. 1977 460,fuelie pistons,D3 heads, 214/224*@.050, 513/534 lift,112 C/L. cam, Performer intake, Edel 750.

Why does the cam "smooth out" as the engine warms up? It's got nothing to do with the choke, as it doesn't have one. I've noticed this on several modified engines, Ford and otherwise. The cam sounds great (nice and lumpy) when the engine is cold, or somewhat warm, but as it gets to operating temp (195*), it smooths out and idles like a stocker.

Any and all input appreciated.

 

Because without the choke the engine is TOO lean until it warms up. Has nothing to do with the cam, it is a carb issue.

 

I put in an idea why over on 460.com, but that might not be the reason.

Got a question for you though.
I see you have a 77 engine, but you have fuelie pistons in it, what or why was the reason you used those.
Just thinking, was it because the dish not as deep as the older model carb pistons & by using those it would raise the compression some. If I been reading right though, the compression height was a bit different on the later models & they sit lower in the bore, if I remember right.
Neil

 

My engine builder says the fuelie pistons have the same pin height as the early pistons, and with the smaller cave in the piston top, they will develop a bit more compression.

Here's the spec's:

1968-87 pistons - 1.760 pin height - .230 dish - cast
1988-92 pistons - 1.760 pin height - .072 dish - cast
1993-97 pistons - 1.770 pin height - .180 dish - hyper.

I'm no expert but, believe they could run a bit more comp on the later engines because of the fuel injection and computer controlled ignition advance.

Hope this helps....

 

Yes sir, that help a bunch.
Humm, now if the D3 heads have 93 to 95cc chambers & if the 88 to 92 pistons with the 0.72 dish were used, wonder what the compression ratio would be.
Around 9.5:1 not to high for prem pump gas, right.
Neil

 

I dont know what C.R. it is, but I would think 9.5 is in the ballpark. I have had to taylor my ignition advance (mech and vac), but the engine seems to run fine on regular fuel. Haven't needed to use premium yet. Might give it a try though. I get just a hint of ping when its loaded up at low RPM in 3rd gear. My cam specs are in the original post, but its not a very radical one anyway.

Good luck with your build...