Engine/Transmission (1994 - 1998) Piston/cylinder clearance 6BT

[PETR]

Hey guys, i'm looking for a little help with some specs for a project i'm building.



Goal HP: 800ish

3500ish RPM

Most likely to run nitrous/water injection



I ordered a set of standard marine pistons (wider bowl), ceramic coated tops, teflon coated skirts. I ordered these from Woodruff diesel, however, i'm having difficulty getting any further specs from them. Josh (the owner) won't return my phone calls or e-mails



I'm ready to bring my engine block down to the machinist, only thing holding me back is not knowing what cylinder wall clearance to run. I plan to run a standard top ring, "Total seal" second ring, and standard oil rings.



The spec's Josh had supplied me with so far, are as follows:

Main Bearing Bore Diameter w/bearing installed 3. 2715"

Main bearing journal diameter 3. 2660"

main oil clearance main bearing . 0055"

Connecting rod journal diameter 2. 7150"

Oil clearence connecting rod . 003-. 0035

Connecting rod pin bore diameter 1. 5764 Max

Connecting rod bolt torque 40#, 70#, 90# using moly lube

Piston Cylinder bore size 4. 020-4. 0225

Ring Gap

Top RIng . 025 min

2nd Ring . 015 min

Oil control . 015 min



Should i just supply the "Piston cylinder bore size" spec to the machinist and let him figure out the clearance by the piston size? I'd rather supply the "prefered" clearance, as the machine shop is not very familiar with "performance" diesel engines. I'm expecting i'd need to run slightly higher clearance's with my "goals" listed above.



Looking for some help from some of the guru's!!! Thanks guys!

 

[PETR]

-BUMP- Anybody?

 

[Dieseldemon]

I have been setting all the engines that I build to 5 1/2 thous. piston clearance.

 

[PETR]

I got a little help from the machinist. I mic'd up the clearances at . 005, and spec is between . 004 and . 007... It was recommended to me to run . 010. The machinist i brought the engine to doesn't do any "performance" builds, only stock, but he made a phone call to someone who is involved with performance engine builds and he also recommended . 010 to leave a little extra expansion room for the higher combustion chamber temperatures.

 

[Vaughn MacKenzie]

Don't quote me on this but I read discussion about this on Competition Diesel and seems guys were setting up with . 007-. 008" for running approx the HP you are looking for, with . 028 to . 030 piston gap. See if you can see this Engine over bore Question. - Competition Diesel. Com - Bringing The BEST Together