Nice progress! Honestly think the cam duration is abit low for your goals and rpm range but chris has experience in those heads and combos.
Have you tried more like 34-37 deg timing? Mine made best at 36-37
Curious what yours would dyno on chassis dyno. I dont know many guys with a big block auto trans/ th400 deals. My 555 didnt impress me on dyno but i only made 3 quick pulls. Even with 4500 intake with 102mm throttle, its seeing 2-2.5” of vacuum at wot. Dual 3” is too small so might also be killing power. Should have ran it at the track once. I guess i still can but in middle of turbo build
Nice progress! Honestly think the cam duration is abit low for your goals and rpm range but chris has experience in those heads and combos.
Have you tried more like 34-37 deg timing? Mine made best at 36-37
Curious what yours would dyno on chassis dyno. I dont know many guys with a big block auto trans/ th400 deals. My 555 didnt impress me on dyno but i only made 3 quick pulls. Even with 4500 intake with 102mm throttle, its seeing 2-2.5” of vacuum at wot. Dual 3” is too small so might also be killing power. Should have ran it at the track once. I guess i still can but in middle of turbo build
Yea I agree, the main reason for only 250 260 dur at .050 is the comp ratio I have. Chris milled the heads down, I have a thin mls gasket and still only net 9.6:1 comp. One day when i rebuild it I'll toss in some pistons to up the comp to 11 or so:1 for pump gas. Then we may toss in a bigger roller in there. Should be pretty easy to run 9s with a few little mods. 10.35@129 is the best so far.
Yeah thats the problem with bbc. Head chambers so big you need a dome to get any compression. Mines 10:1 with flat tops with small 109cc chambers
Yea the promaxx 317s I have are 115.2cc chambers. That's the most chris said he could mill off of them. Still, runs 10.30s at 9.6:1 comp and pump gas. Not too bad. I'm running 36 deg timing. Seems to be a good spot for it.
Update for the winter. No too much going on. Just doing some maintance on it. No performance upgrades this year. Plans for next year is a full rebuild and new slugs to up the compression from the 9.5:1 it has now to about 11:1 or so to keep it pump gas friendly. Also larger headers because I have a good feeling the ones I made in the spring of 18 are way too small for this power level. At the time my only intention was to run the merlin 509 as it was, which only pushed out about 540hp crank at best. And even then i was cutting it close with 2 inch primary's 3.5 inch collectors. Then I was only reving to about 5500 ish rpm. Now that's my stall roughly....
My little girl sure does love all the buttons on this car especially the transbrake button.
Figured id update this thread. Car has done well the last 2 years. Pretty conisitant st 10.10s-10.20s at 129-131mph.
Pretty basic stuff. 950cfm carb, 9.6:1 comp on pump gas. Car is still heavy at 3575lbs race weigh from the full interior, cage, frame ties, drag bar,bbc, and s60 rear. 3365lbs without me. A few video links below of some races this year.
I still feel this bbc swap was far the easiest way and most basic to run the times I am. Im sure if I went with a wild cam, more compression and reved it up more on shifts (I shift at 6500 and trap 6900) it wouldn't be too terrible difficult to make some high 9 second passes, bit its all about conisitanty now so i am just trying to make the same time over and over.
I rebuilt the motor over the winter. No mods just a freshing up. Raced last weekend and the cars got alot more power now. Best 60 foot of a 1.319 and best eighth mile of a 6.36@107mph. Some cool pics of wheelies too. Going to limit the front suspention in hopes it keeps the front end down and goes a bit faster.
