engine combination possibilities

[superturbocompound]

i just managed to get a hold of some parts catalog and noticed that the 4jg2 and the 4jh1 share the same bore(95.4mm) , this would make it possible to have a 3.1 direct injection by using the 4jh1t pistons and liners ,the other items that i thnk needs changing would be the head(direct injection head) fuel pump , fuel lines and injectors, all of which i think can use the 4jb1t components,300cc increase....comments please

[superturbocompound]

300cc increase compared to the 4jb1 i mean

[geeves]

I wonder how much fuel you can squeeze through those injectors?
Isuzurob is running a detuned 3.1 pump on his 2.8 so the 3.1 pump would still work which makes it a little simpler.
Without looking at the fine print it sounds like it should work

[Roderunner]

Nothing is ever that simple, but it would make an interesting project ! I would expect to run into problems concerning piston pin height, conrod length, liner interference fit differences etc., wouldn't a complete 4jh1 be a better engine anyway?

[geeves]

isnt 4jh1 3.0 litre. If this is the case then only the stroke is different. A crank change might also work.

[superturbocompound]

judging by the pdf file , 4jg2 is some what different from the 4jh1,piston pin is smaller 34mm(4jg2) 31mm 4jh1,so roderunner is right about this not being easy,but lets see the similarities
1) the cylinder grade from the manual are identical for both 4jh1 and 4jg2 (from the 4jg2-4jb1 manual)
2) 4jh1 piston bowl looks similar to the newer 4jb1 type piston injectors should work.

i need to drop by my friends parts shop to measure the piston pin height, he's got both 4jg2 and 4jh1 i think.

Roderunner wrote:Nothing is ever that simple, but it would make an interesting project ! I would expect to run into problems concerning piston pin height, conrod length, liner interference fit differences etc., wouldn't a complete 4jh1 be a better engine anyway?

buying a 4 jh1 engine is expensive, and alot of us either have a 4jb1 or a 4jg2 laying around some where, so its just a possibility that could happen.a 4jh1 also runs an ECU which makes it alot more complicated.

[superturbocompound]

got a call from the isuzu parts shop(a friend of mine) that its a waste of time...just get a 4JG1 pistons and the jobs is done,piston pin size and pin height is identical to 4jg2 but with a combustion bowl for direct injection...oh well

[geeves]

Ive heard of 4jg1 parts but never ever seen a reference to a 4jg1 engine. Is this a mythical beast of the same nature as a 4.88 diff?

[MUVIT]

so will a 4jg2 accept a 4jg1 head & pistons?

[isuzurob]

4jg1 were very rare are a few in taupo, more in elf trucks than bighorns, holden dealers can get new parts for them still