home porting small block heads

[AdamR]

Is it worth the time and effort to gasket match the ports,clean up the bolws and polish the chambers on my 1.88 valve J heads ?

Ive never messed with heads before and dont want to go crazy and ruin them, but I figure while they are off there may be a few ponies in there.

Its a pretty mild combo.

It will be in the 9.5:1 range,XE274,LD340 intake 650 Carb, 10" converter 28" tire and 3.91s

 

[GotDart]

Is it worth the time and effort to gasket match the ports,clean up the bolws and polish the chambers

I think it all depends on how and where you spend your time. If you are looking at that XE274 cam, the total lift is under .500". So in my opinion there is not going to be much gained working on the runner of the intake port. Just smooth it out a bit, and make sure the port opening in the head matchs the port on the intake manifold. There is no need to open both up to match the intake gasket. Spend most of your time cleaning up the bowls and the short side radius (the transition from the bowl to the port runner). Don't go wild trying to hog it out, just remove any sharp edges and smooth all the transitions. I have heard the exhaust side is more restrictive, so that is probably where you'll get the biggest gains. I would guess you could pick up 10-15 hp with a few hours of work.

 

[AdamR]

Thats the plan. Clean them up abit. Nothing fancy.
Have a nice valve job done and mill them to get the compression up a bit more.

 

[GotDart]

When you get the valve job done, have them backcut the intake valves. That alone should be worth a few cfm.

 

[mikesduster]

i agree.....port match them and clean everything up!!!

talk to MOPER about the machining and porting if your not comfortable doing it.