Cat c15 Sdp rebuild help

I prefer to go no thinner than a .030 shim.

 

like I said earlier. very seldom does a cat blow a head gasket without a root cause. seen it all too often guys just measure the protrusion as per the book and its "within spec" and they simply put another gasket in.

removing your liners and measuring the material recession around the liner flange seating surface, has proven to you what the root cause of failure is. Unfortunately most times when this occurs the fire ring frets into the head face. Without close inspection that can go unnoticed and cause another gasket failure.

the machine shop takes hardly anything off when they face it to repair the fretting. they can do it with the valves still in and it gives you an excuse to reseal your injector sleeves

 

what pistons are you putting in it?

 

spewing your pistons are so new. perfect opportunity for 16:1 comp pistons.

I still use genuine cat rings on the rebuilds I do.

 

we go 16:1 and 70 pin ECM so no IVAs. we also go single turbo too. but its expensive to do that.

I don't care what emissions based sales pitch anyone provides to justify the IVAs. cat needed the comp and the boost to burn the fuel in a hot enough combustion process to meet emissions. but that dynamic cylinder pressure in a truck application with decent HP was never going to be durable. so basically they put jake brake on the inlet valve to bleed off some cylinder pressure and keep the liners from milling into the block and the head gasket from torching.

if it were my truck id rather go 16:1. if it were mine id be fitting 16:1 pistons. if you didn't want to or budget didn't permit id still fit the 16:1 pistons and keep the twins and IVAs. id just set the IVA clearance to 0.055" so they weren't as aggressive.

 

70 pin and old school injectors with an early file have a reasonable amount of timing about them and burn much cooler and more efficiently. you need to go back to a 6nz or 800hp marine cam also to gain the benefits. if you have someone you trust enough to turn your 120pin ACERT ECM into a 6nz then by all means. everyone that writes files here stretches the inj pulsewidth and rings the neck of the injector tip. with the same size injector the only way to get more fuel in is by increasing the time the fuel is injected over. a tip can only physically flow so much volume. you want more volume it needs to be delivered over a longer period (more pw). believe it or not but the rest of the engine doesn't wait for that to ocour. it keeps going. meaning fuel is stil being injected as the piston is traveling down... excess heat, carbon build up from incomplete burn, oil consumption...etc etc.

with a 70 pin and 8501 squirts I know everything is as it should be and no "tuner" has poured extra juice in....while the piston is moving away from TDC. if I want more power I step up to 8502 squirts.

the 70 pins seems to drive much nicer too. in my opinion

but 70 pin means changing cam gear and installing the sensor in the timing gear backing plate