Felix C

Secured a set of 243s. Cam is .578" lift so really do not need flow nos. and the required porting beyond cam lift peak.

Looking at mid and low lift nos.

what mods work best on a 243 to increase the low and mid nos. A valve job? What type? I read a poster 243s pickup quite a bit just with a good valve job.

Same for 241s by the way.

pantera_efi

iTrader: (1)

OK, you gave me a great idea, change the intake seat angle to 30* as is on the Ford FE engines for NASCAR Racing.
I have a cut head, one cylinder 823, for back/back testing on my flow bench.

My choice for low lift flow increase is for the WIDE lobe center cam use that I like to fit that ALSO allows for higher static compression and flat top pistons.

What diameter of Intake Valve should I test ?

Lance

A.R. Shale Targa

iTrader: (2)

Back in the sixties Buick, Olds, Pontiacs had the 30 degree seats to maximize the area for Flow when .400"-.430" lift cams were prevalent. Drag racers with .900"-1.00 valve lifts have been using 50-55 degree seats for years since nothing under .500" even matters to them
The OP would be best suited to send the heads to AI for a valve job and perhaps a CNC chamber program to pick up 20 or so cfm and maintain a small high velocity intake runner

truckdoug

iTrader: (25)

I'd suggest the standard 2" cathedral port intake valve, since low lift flow likely means more to that crowd.

Felix C

I was reading from a on older post by someone at Bauer Racing, jr or sr., that 243s flow to 285cfm with a good valve job. Type of valve job done for Stock Eliminator racing where only a VJ is allowed.

A.R. Shale Targa

iTrader: (2)

Correct so my guesstimate of twenty more is close since AI claims 265 stock

KCS

iTrader: (20)

One of the best things you can do for low/mid lift flow is to increase curtain area with a bigger valve.