crewcabxlt

got a couple of parts motors. a low mileage 24 v an a 12v w/ some rust pits in one bore. i want to put 12v pistons in 24 v block. any problem doing this. ideal piston/bore tolerance ?

Dieselbuilder

what head will you run?

crewcabxlt

12v. was going to p-pump 24v, but think i,ll stick w/12v.

Dieselbuilder

12v head with 12v pistons 24v head with 24v pistons, bowl on pistons are different if going with 24v head and p-pump the best power con-fig would be 03 ISB better bowl shape for advance timming

crewcabxlt

o.k. thanks. looking specifically at putting 12v pistons in 24v block, 12v head. switching 12v pistons from one block to the other.

infidel

Injector location on the head and piston bowl shape differ between the 12 and 24. They're designed to be used together.
Not a good idea to mix the two systems up.

JD730

What's 24 valve block is it? Not a 53 I hope.

I can look the piston/bore diameters up later this week when I get my books out.

crewcabxlt

guess im not being too clear- ive seen differences in piston bowls/adifferent years etc. not mixing heads and pistons. i want to put good used 12v pistons in a good 24v block- put 12v head on and a p-pump. i know cummins had 3 grades of pistons a,b,c. . but im not familiar w/ diferences. i,m sure someone has thrown good used pistons in a different block. whats ideal tolorance ?

Tate

All the parts are physically interchangable. Graded pistons (A/B/C) are for piston protrusion. Not sure what ideal is, but on Morkable's stock CR long block, most pistons were at .010" above deck.

Sensor fittings maybe different, since it seems the early 12v's used NPT threads, and the STORM blocks are o-ring metric.

GAmes

If you plan on a p-pump what will you use for a lift pump? 24 valve cams don't have a lobe for a 12 valve pump.

crewcabxlt

ok, thanks. going aftermarket cam or slide in a 12v cam. the piston grading is confusing to me. i thought it had to do w/ bore tolerance. apperently it woul effect compression ratio?

JD730

Tolerances according to the book.

Cylinder Bore ID Min 4.0157" Max 4.0203"
Out of round Max .0014"
Taper Max .003"

Piston Skirt Diameter (worn limit) Min 4.0088" Max 4.0113"

crewcabxlt

thanks for replies !