HELP! Need 318 Head Suggestion (info provided)
I agree with this. IMO, omahamoparguy has great advice that should be re-read. The stock head is just absoultely fine for what your doing.
I've run a dead stock '79 - 318 with just bolt on parts and a small cam Crane cam (216 - 228 - C-112 .454/.480 lift.) & 3.21 gears to 15.14 in the 1/4. (2.2 60ft.)
That would mean 7.8-1 comp. ratio and stock valved heads. More compresion and the 1.60 exhaust valve would have been a nice addition to that build.
Of course you agree...... :scratch: :thumbup:
Omaha is on to it, however, the pinch in the small port heads isn't the bottleneck, the bottleneck is in the bowl. (mildly ported)... Yes, adding the bigger EX valve and a same/same cam..... (about that)
The higher exhaust flow at lower lift (starts faster) helps at higher RPM
The same/same cam, makes more low end than a cam with a longer EX duration.
So, with the change of the EX valve size (providing they are stock(ish) heads, you get a nice low end, (important to small motors) with a nice finish. (the point of the longer EX duration)
Any engine builder that wants you to just throw away your small port heads on a mild 318 is just trying to.....
(1) take the easy way out
(2) Doesn't know Mopar
(3) trying to make money off of you with minimal effort
(4) thinks your rich
(5) all of the above