Just wondering what compression should be at ?? I'm getting about 135 PSI in cyl 1..? Just had it rebuilt and so far not happy with performance, Werby figured about 375hp and 425ft/lb but doesn't feel close to that..
Don't just let it hit one pulse on the tester. Most of the time 3-5 will show a good average where it starts to flatten out. And alot depends on CR what pistons you selected, what heads, head gaskets all played a little factor. That would give a better ballpark number for your PSI.
I for one in my "truck 390" start at 9.5 CR pistons. And when I put a serious load on it IE my Minneapolis Moline tractor 7500# then I splash in the 93 octane.
Well remember thats a heavy Bird, so Gonkulator still just says 91-92mph trap speed.
If you dont have a Gtech, try some stopwatch times before & after tuning if your speedo is fairly accurate.
My cool Iphone has a laptime feature, so you could in theory get
all in a single blast.
Before & after tune will tell you a lot (even if the speedo is off in a relative sense)
Yes that 135psi seems low to me too, since you have a pretty small cam in there, about a 428cj cam.
Was that just 1 cylinder or all 8?
the rings and valves are sealing. Who did the build, ask him/them, could be a broken ring, leaking valve to seat(s), etc. A cylinder leak-down test will tell the tale. It should hit 75psi. on the first kick; what are the rest of the readings?
No I just tried it on #1 because its the easiest one to get at in that tight engine bay.. But don't you think I should be able to roast the tires if I wanted too..?? Is there a better cam that I could look into ? I think I do want more power..!!
Just a "chirp". Stopwatch or Gtech would tell the story
August 6 2013, 9:37 PM
Roast the tires depends -
We had our Galaxie setup much the same as your Bird once, 3.50 gear and about the same cam and weight.
Just a chirp is all we'd get now and then with the stock converter.
Then again the Galaxie is already almost 50/50 weight and has good transfer.
I've never had a 60s Bird so not sure how they are on traction.
The stopwatch times would give an idea, even approximate, if it is about right or way off.
As for compression, you can even have a valve not seated just right or corroded from sitting the night before, it will clear up but if one reading is all you have it doesnt tell much. Also as noted be sure its wide open throttle, all plugs out, good battery, do 5 or 6 hits on the gage then call it good, same number each time. I test em cold (well, 60F or so anyway), they probably read a little lower but better consistency.