Hot restart issues.
Engine was very tight whe turning by hand before initial run in of the cam. Any thoughts??! TI
Lemmee guess;
Are you running?
KB107s in at near .0015 skirt clearance, and cast rings at the recommended tight gaps?
At the KB specs, I had the same hot-running issue with mine, even with Alloy heads.
I have set up this engine, with oiling mods, and she runs more than enough spring pressure to rev 7500, and I regularly shift at 7200.
In 25 years, my car has had 3 cams.
1) The first was a 292/292/108 Mopar, in at 11.3Scr,
it ran hot. I suspected the cam.
I didn't like that cam anyway so I pulled it out and sold it to racer, who loved it.
2) The Second was a 270/276/110 cam (223/230), still at 11.3,
it still ran hot.
I had to take the engine down.
I loosened up those skirts and reinstalled those pistons, with Plasma-Moly rings, with much looser ring gaps; and I reduced the Scr to 10.7;
With the heads off, the crank had very little resistance to rotating.
The skirts were assembled at around .0035, and
the top ring-gaps were over IIRC, .032
Second gap is only a little over the recommended gap,
No more issues!
Obviously; In my case, the KB specs did not work.
Set up like this, this 223 cam got as high as 32 mpgs. I really loved that cam, but one day, it lost lobes
3) so next up was; a 276/286/110 cam, (230/237),
with the Scr now 11.0.
This cam has gone 93 in the Eighth at 3450 pounds, me in it. I luv it, but
Even with overdrive, it sux gas. With this cam, I have tried final drive ratios as low as
2.52 (65=2040, but finally settled on
2.77 (65=2240). Engine now has over 100,000 miles on it; and hot-running is decades behind me.
Don't let the loose specs scare you.
EDIT
FYI, my timings are;
Idle-Timing of 12>14 @700
Power curve is Two-stage ; 28*@2800 going to 34@3400
Vacuum advance is 22* coming in fast and hard.
Cruise Timing at 65=2240 varies from 56> 60 degrees, by Dial-back
Parade-Timing is 5*@550rpm. also adjusted by Dial-back.
Dial back is an old Jacob's dash-mounted, electronic timing module, with an adjustability range of 15 degrees, that I set for up to 6*Advance/9*Retard..