4jg2 most HP

[rustyvr4]

just a curious question for those who have or had the 4jg2t engine. what is the most horse power you can get out of them?, and maintain good reliability. what are the steps taken to get the horse power you got or are getting?

[tonkamu]

You can get a lot out of any engine if you spend big money. Do you mean decent gain in hp while keeping it reliable? Is it an efi or mechanical pump. Just the usual mods is about all you can do, unless you go bigger turbo and more fuel. But I don't think 4jg2 heads last long with a lot of boost? Even what you're running 20psi is more than what's considered "safe" on 4jg2 from what I've read, safe max is 15?.

[geeves]

Best way to go with 4jg2 is 4jg1 pistons 4jj1 or 4jg1 head and diesel pump 12mm plunger in pump and tune away. You are looking at a full recon to do this and it would only give a little more power than you can get out of a 4jj1 which would be cheaper to get by buying a low mileage holden ute and stripping

[rustyvr4]

model i have is mechanical pump. so far on the pump i.v adjusted the boost comp, rotated the cone shaped thing and backed off tension on spring. adjusted fuel rate screw. and backed of, cold start device adjust screw. been running peak 20psi nearly a year. 100kmh on open road she pulls 8psi. yet to do intercooler and proper exhaust. can i go to big on intercooler? thinking about using this as a top mount https://www.trademe.co.nz/motors/car-pa ... 476944.htm

[geeves]

That intercooler is designed as a front mount for a smaller engine. Front mount is always going to work better but there are plumbing challenges. Factory intercooler with an added fan will do as well

[handymanny01]

Thought I'd share my experience in this area... my 4jg2 had been running 20 psi, VF10 hybrid , and a maxed out std injection pump,, for years,,, with water to air intercooler,, and 3" dump and full 3" system, 3" inlet and pod filter... (and all normal mods like egr delete) dynoed recently at 95kw / 127hp at the wheels,,,, Then fitted a REAL hot rod injection pump,,, Holy shizz!!! Estimated 125kw at wheels (145kw ish at crank) Sadly only lasted 2 weeks,,, serious piston damage,,, (as it flew past 160kph on 33's) So I'd say safe limit on 4jg2 is prob 100 kw at the wheels... and 600 c on the EGT ,,, 650 c for brief periods,,, Next build is 4JG1-T (will post all details , and dyno result) stay tuned!

[AusZuMu]

Looking forward to the updates Handymanny01, I have a long list of maintenance and servicing tasks I should do before I get into the performance mods for my 4jg2.

[handymanny01]

Gotta say,,, these are TOUGH little engines!! (4jg2) Pulled her to bits over the week,,,, over 300'000 kms,,, and the crank is still within service limits! And the recent blow up, damaged 1 piston and liner,, and that's it! 4jb1 head purchased, and slowly sorting which 4jg1t pistons are the most suitable,,,, then the 4jg1t rebuild will begin!! Liner removal pics to come...

[handymanny01]

The damaged piston.... prob the result of squeezing an estimated 140kw (crank) out of it... lol

[handymanny01]

Pressing the liners out of the block,, needed to make a special tool.., bout 5 ton to press them out... block seems totally fine.... will prob get it decked very lightly though.... just so it's perfectly flat,,,