I'm now in some troubleshooting of my new setup....nothing change about car setup, only engine wise. So here are the spec/time slip of the old setup vs the new one....

car setup first same as last year, subframe, 28x10x16 hoosier slick, 3500 10"1/4 stall, 700r4, 4.10 gear, aeromotive ss pump with bypass reg,headmen lt 1"5/8 with 2.5" dual magnaflow muffler 3600 pound race weight

old engine setup
357, stock rotating assembly, 9.3:1 comp
heads rpm perf 64cc, stock.....had 2 bent valve when we inspect them before install on the new setup
cam xe274 flat hyd. with 1.6 roller tip only....spec 230/236 duration at 0.050'' and .487/.490 lift.....two wiped lobe when removed
intake rpm air gap
carb holley 650dp....#74 pri #78 sec
timing problem about 20 deg locked

last time slip before removal
60' 1.65
1/8 7.79
1/8 mph 88.79
1/4 12.33
1/4 mph 109.84

reason off removal....simple refresh, burning alot of oil....problem was out of round cylinder....about 0.010".....so was officialy dead

new setup
freshly machined 357, with forged assembly, balanced, h-beam 6" rod, forged flat top piston....10.5:1 comp
same head new spring for the "better" cam
spring spec
I.D. of Outer Dia.: 1.060"
I.D. of Inner Dia.: .700"
Seat load: 155lbs @1.850''
Open load: 420lbs @1.250''
Coil bind: 1.195''
Rate: 441lbs/in
new cam crane 118551 recommended by crane
Camshaft Duration @ 0.050 in. I/E: 236 / 244
Lobe Seperation Angle: 112
Rocker Arm Ratio: 1.5
Valve Lift (in.): .525 / .543
mecanical roller lifter/comp pro magnum roller rocker 1.52
same intake/carb except #76pri/#80 sec
38deg locked

new time
60' 1.61
1/8 7.72
1/8 mph 87.62
1/4 12.25
1/4 mph 109.6

same track....same lane....almost same temp.....
im now in some doubt about this supose to be better engine, maybe some of you can help me out a little.....put quite alot of money in this thing ...

thanks alot

Seb

 

well all you changed was the compression a little bit, small increase in cam size since you used 1.6 rockers before your cam was really a .519/.522. unless the lift you showed was with with the 1.6's. You did add some heavier pieces in the engine. The forged bottom end doesn't make hp at all might even take some. If your distributor was locked on the first motor at 20 degree total timing you are lucky it was.Because the dissappointment would have been even greater. Since, it probabaly would have run better with more timing. In my eyes you ran good for your engine combo and weight. Is the new cam a solid roller or a flat tappet? I can't tell by your description. You might want to try some 1.6srockers if it is a solid roller and the springs can handle it.

 

38* seems like a lot for a set of rpm heads...i'd think the combustion chamber design would need less timing than that.

 

oh....well i knew there was no big incress between the two but was expecting atleast a 3-4mph more and some high 11 on it.....well my buider told me it should be better....when he was showing all the wrecked parts on the other setup

btw the new cam is mec roller

is there thing i can work on to get better like intake or carb change....or its not worth

i'll check my timing....didn't have my timing light today, did some guest timing but put to much retard and went 12.50 at 108
thanks

 

it's gonna take a while to get it running 100%. it's a new combo, you should have expected some tweaks

 

it may need a little more carb, but you need to be patient, tune it out, get it running up to its full potential before you get too down about it.

 

sure it was the first time at the track....i'll try to find a vic jr and 750dp just to test....my builder recommended this before swaping out heads.

thanks for your input

Seb