[F-BIRD'88]

At least you got decent headers.
because this motor may have a dished piston, you may be ablle to cam it>

valve to piston clearance must be checked before running>

if you were to degree in your present cam and then trial fit it by bumping the cam gear ahead 1 tooth, and then back 1 tooth on the chain>
and check VTP clearance with the cam advanced , then retarded and read the .050" timing points and lift @TDC.
a new cam can be selected. 1 tooth movees the cam ahead or back aprox 230deg. Don't guess, degree it, then move it and degree again.
The intake valve to piston clearance is going to be the big issue.
a verified .050" clearance is good.

the valve to piston interference closest point will be +/-10 either side of TDC.
don;t guess, check it.
if you don;t under stand this, get someone who does , to help.

to help you select a new cam that will fit, I need to know howe far you can advance the cam ahead before it hits the piston, when the crank is rotated by hand. And then how far you have to move it back again to get a .050" clearance. Then I need the checked .050|" intake valve open close events timing points from the degree wheel.

you will need tow solid lifters, a degree wheel. a dial indicator and stand, a piston stop, a a light tension valve spring. And a valve spring leverage tool.

Just throwing a cam in this motor without verifieing VTP clearance will pretty much guarantee engine damage. ( non stock valve angle-location)

[big bad 390 fe]

hey man a tunnel ram doesnt gain much ponies but look cool.

[F-BIRD'88]

Originally Posted by big bad 390 fe

hey man a tunnel ram doesnt gain much ponies but look cool.

hey man: a tunnel ram will make a lot more power than any other intake manifold can. You just have to bolt it on a real motor and don;t restrict it with tiny carbs, tiny cam and tiny exhaust.

look at the most powerfull old Ford FE motors (390-406-427-428) they all came with dual quad hi rise manifolds and big dual carbs.
the 427 tunnel port nascar motor had a tunnel ram manifold and two big carbs.
tiny carbs kill any of the dual quad manifolds including the tunnel ram .
its all on the combo.

[F-BIRD'88]

It would be real nice to shave off about .040 .050" off those ehads and use a thin head gasket to get the real compression ratio up to snuff.

This also moves the valves closer to the pistons and needs to be accounted for VTP clearance. The real compression ratio is not goig to be even close to 9.8:1 as the block is most likely not a true 0 deck . The chamber volume probabily is not at spec either. i bet its barely 9:1 actual.

-12 cc D dish pistons. stock ish deck clearance .025"+
typical 9cc ish .040" + gasket

Port flow can be improved with some hand porting.

its all in the details.

[matts37chev]

Originally Posted by F-BIRD'88

hey man: a tunnel ram will make a lot more power than any other intake manifold can. You just have to bolt it on a real motor and don;t restrict it with tiny carbs, tiny cam and tiny exhaust.

look at the most powerfull old Ford FE motors (390-406-427-428) they all came with dual quad hi rise manifolds and big dual carbs.
the 427 tunnel port nascar motor had a tunnel ram manifold and two big carbs.
tiny carbs kill any of the dual quad manifolds including the tunnel ram .
its all on the combo.

I think that post was some troll action

[maverickmechanic13]

Today 05:18 PM
big bad 390 fe hey man a tunnel ram doesnt gain much ponies but look cool.

You obviously havent read any of this thread. But i do appreciate your enlightening insight and advice in the world of tunnel rams and high performance.

F-BIRD'88
It would be real nice to shave off about .040 .050" off those ehads and use a thin head gasket to get the real compression ratio up to snuff.

This also moves the valves closer to the pistons and needs to be accounted for VTP clearance. The real compression ratio is not goig to be even close to 9.8:1 as the block is most likely not a true 0 deck . The chamber volume probabily is not at spec either. i bet its barely 9:1 actual.

-12 cc D dish pistons. stock ish deck clearance .025"+
typical 9cc ish .040" + gasket

Port flow can be improved with some hand porting.

its all in the details.

It's actually pretty close to the value i stated (9.8:1). It may actually be more - when i did the math, i actually forgot the actual thikness of the head gaskets i used so i used a higher value. And i'm pretty sure i can go bigger camwise, but i mas making pretty good vacum before with that cam, so i may keep it for just a little bit.

[F-BIRD'88]

its probabily more like this
the details matter.
http://www.wheelspin.net/calc/calc2.html

[maverickmechanic13]

Oh heads have been shaved down already. Oops.

[matts37chev]

Originally Posted by F-BIRD'88

its probabily more like this
the details matter.

thats a handy looking calculator

[F-BIRD'88]

Originally Posted by maverickmechanic13

Oh heads have been shaved down already. Oops.

What is the chamber volume now?
what is the piston deck clearance @TDC.?

[F-BIRD'88]

but i mas making pretty good vacum before with that cam


???? how is that a measure of good?
carbs and throttle response is not about manifold vacuum.
carbs do not work on vacuum , they work on venturri vacuum created by air flow thru the carb venturii.

Your problem is a lame tune up. Fix the distributor curve.

[maverickmechanic13]

Ok ill fix the curve when the motor is back together buy I have a bad feeling it's gonna be pita to cold start.

[matts37chev]

Originally Posted by maverickmechanic13

And i'm pretty sure i can go bigger camwise, but i mas making pretty good vacum before with that cam, so i may keep it for just a little bit.

more cam if possible

Originally Posted by maverickmechanic13

Ok ill fix the curve when the motor is back together buy I have a bad feeling it's gonna be pita to cold start.

if its tuned ok, it will be fine




now after both of those statements.......are you building a drag car or your wifes mini van?

[maverickmechanic13]

A hi-po minivan would be sweet

[F-BIRD'88]

The correct curve with much more initial advance at idle.
( start with locked out timing) will make it much better on cold starts.
Remember to not allow the motor tyo idle low untill some heat gets up in the runners and carb base.
this will avoid plug fouling. 2000-2500 rpm as required at first , till it warms up.

Hot restart, starter strain. Use a ignition power interupt switch when starting hot to relieve the starter load.

if you have the motor apart why not measure the VTP clearance.