Iron Block 370 W/ L92 Heads, L76 Intake
06-13-2010, 02:53 PM
#21
I know the feeling, the same thing happened to me. I was tuning and couldnt add more fuel, noticed my injector duty cycle was over 100% too. I knew that my injectors should be good for another 75-100hp. Checked fuel pressure and it was dropping to 35psi.
The tuner kept adding fuel and adding fuel and finally I was like; 
"Maybe we should check the fuel pressure?" LOL.... 
06-14-2010, 01:01 PM
#24
Mike
07-14-2010, 07:10 AM
#25
Teching In
Join Date: Jul 2010
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idk how people arent coming closer to the 550hp mark?
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07-29-2010, 02:34 PM
#31
Thanks man. With the 387, one of the connecting rods didn't want to play well with the others so it exited the side of the block. The machine work for the Darton sleeves wasn't done correctly and it shifted, causing excessive bind on the piston. I won't name the company who did the machine work, but they used to have a large facility in Houston.
Mike
Mike
07-29-2010, 02:43 PM
#32
Another update:
-Replaced fuel pump with Walbro intank 255lph
-Upgraded fuel injectors to 42lb SVO Green Tops
-Rescaled injector flow table in the PCM
Got the car back on the dyno and the hp curve flatlined at around the 400hp mark at 5300rpm. Something wasn't right so we did a compression test and two cylinders were way down on compression. Squirted a bit of oil in all the holes and the compression came back up so I'm thinking the rings didn't seat correctly. It's puffed some oil on occasion but I attributed that to the larger ring gaps for nitrous use. I guess the rings didn't fully seat. Now I'm tearing down the engine to re-hone and re-ring it.
Just another bump in this problem-riddled season..... I've been to the track one time so far this year.....
Mike
-Replaced fuel pump with Walbro intank 255lph
-Upgraded fuel injectors to 42lb SVO Green Tops
-Rescaled injector flow table in the PCM
Got the car back on the dyno and the hp curve flatlined at around the 400hp mark at 5300rpm. Something wasn't right so we did a compression test and two cylinders were way down on compression. Squirted a bit of oil in all the holes and the compression came back up so I'm thinking the rings didn't seat correctly. It's puffed some oil on occasion but I attributed that to the larger ring gaps for nitrous use. I guess the rings didn't fully seat. Now I'm tearing down the engine to re-hone and re-ring it.
Just another bump in this problem-riddled season..... I've been to the track one time so far this year.....
Mike
08-06-2010, 03:19 PM
#34
Another update:
I ended up pulling the engine and found numerous problems. Six of the eight intake valves were contacting the pistons even though I checked PTV clearance during assembly and had .080" on I/E valves.... The ASP underdive pulley/balancer had two cracks in the rubber isolator causing it to slip back and forth about a half inch. Now I think the billet double row timing chain is fucked because of the broken balancer. It never seems to end.....
The original dyno sheet or the newest one with all the issues? I have the first one but I don't have a working scanner at the moment.
Mike
I ended up pulling the engine and found numerous problems. Six of the eight intake valves were contacting the pistons even though I checked PTV clearance during assembly and had .080" on I/E valves.... The ASP underdive pulley/balancer had two cracks in the rubber isolator causing it to slip back and forth about a half inch. Now I think the billet double row timing chain is fucked because of the broken balancer. It never seems to end.....
The original dyno sheet or the newest one with all the issues? I have the first one but I don't have a working scanner at the moment.
Mike
08-18-2010, 06:54 PM
#38
Mike