View Single Post
Old 06-13-2011, 12:55 AM   #9 (permalink)
Even a caveman can do it!
b1jetmech's Avatar
Join Date: Mar 2010
Location: Michigan
Posts: 5
Thanks: 0
Thanked 0 Times in 0 Posts
Hey thanks for the response!

After a few months of driving with the converted diesel I'm averaging 20 MPG. That's up from 11 which isn't bad I must say.

I think it can do better because a couple of thinks need attention. First the injectors HAVE to be replaced. Sometimes I get grey smoke which means unburnt fuel so the injectors after having almost 200k miles on them dare not providing the best spray pattern.

If that helps but the mileage doesn't improve much then the injector pump will be looked at.

Then engine runs great. There is NO blow by which is unheard of with these but being a non turbo didn't have to suffer the abuse of turbo because GM kept these engine's compression ratio very high. Just like Ryan said, Too much compression plus boost = BOOM!

I do have a turbo set up but won't be installing it anytime soon. I'm having the urge to convert back to gas. Want to try a 305 tune port from the late 80's early 90's because they got good mileage and having tune port gave it a real good low end torque but we'll see!

Another item on the to-do list is turn the fuel up. I have a hard time accelerating up to highway speeds because the motor runs out of steam about 55 mph. The fuel curve is way below because this engine doesn't belch smoke. I have never seen black smoke under any load. so an 8th of turn on the IP should wake it up a little.

over all I do like it but have the tune port ideal in the back of my mind we will see on that one.

Ryan, If I pull the heads for anything I just might install some 6.2 pre cups. I have heard of 6.2 Burbs getting in the mid to upper 20's in MPG. The differences between the 6.5 non turbo and the 6.2 is larger bore on the 6.5 and cylinder heads. 6.5's have smaller exhaust valve to prevent the cracking between valves on 6.2s.

99' Suburban K1500
6.5 diesel non turbo/4l80e conversion
Out with the gas 350!
  Reply With Quote