RPMagoo
Just An Old Motorhead
-- I agree. -- Cut good lights, and Kick A_ _.-- Jeff... Absolutely NO MORE ANYTHING till you take it to the strip as it is!!!!!...
Next steps for more power - 318
- Thread starter MrJLR
- Start date
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barnett468
Well-Known Member
what intake and exhaust do you have?
installing numerically higher gears will increase the acceleration rate.
installing numerically higher gears will increase the acceleration rate.
nm9stheham
Well-Known Member
LOL... there is always more. Jeff, a bit more info would help focus the feedback.
- What is the main intended use of this car? Street/cruise only, pure drag race, or what? A mix?
- What pistons did you put in? This is so we can see where the CR is now; that, plus the intended use, will impact the best choice on head chamber size.
I'm just going to use it for street cruising and occasionally run a 1/4 mile. ..
Stock bottom end..compression is low...guessing 8.5:1?
Jeff
nm9stheham
Well-Known Member
More likely around 8:1 or a bit less. Do you know the piston model used? Were they real flat tops, or did they have 4 valve reliefs? (Sorry if you said so before and I missed it....) ANd, BTW< I am assuming standard Felpro head gaskets were used.
So you can be thinking a bit for the long term: This lowish SCR with larger chambered heads like the X or J heads is what causes a combination on the street that lacks low end torque; the resulting DCR is just too low. It will run fine when wound up at the higher RPM's and may be A-OK on the strip, but most of your street driving and cruising will be at the lower RPM ranges. Torque is what needs to be preserved for a responsive engine at the low RPM's, and that comes from a decent level of SCR (and thus DCR). With that approach, you end up with a wider torque range, and a better all-around driving engine.
As suggestions, investigate the Magnum heads, the Indy LA-X type head, and the Edelbrock Performer heads. All have smaller combustion chambers and the latter 2 have the best breathing of the group.
If none of that is in the budget, then the suggestions of a thin 1121G head gasket and some head shaving are good ones. That gasket and a .030" shave will raise SCR by about .6 or.7 points. This will help the low end for sure and will make it perkier on the street, but, without better head breathing, your top end will not be much better.
Find a set of 302 heads and have a good porting job done and mill them a little.
Would be nice to see a before and after with no other changes and then fine tune it for the final number.
Would be nice to see a before and after with no other changes and then fine tune it for the final number.
69valiant21
Well-Known Member
My 30 over 318 with 340 heads, 750 double pumper, air gap, headers, 3.91 rearend, and 3000ish converter ran 13.85. On drag radials.
Just put a 3500 converter in it with a trans rebuild, woke my car up A LOT! Hopefully run 13.50s. My dad drove it and said it pulls like his car, he runs 12.90s.
Just put a 3500 converter in it with a trans rebuild, woke my car up A LOT! Hopefully run 13.50s. My dad drove it and said it pulls like his car, he runs 12.90s.
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