just bought 89 D250 ???

[CKnoop]

Hi all new member long time reader I just bought a 89 D250 727 auto 101,000 miles never been tweeked. My plan is to put the drivetrain into my 84 D350 Crewcab next winters project will do some tweeking in 89 for now, guages first will do injectors and turbo housing, outer cooler as I have $$ How mutch can I tweek the pump and timing on a stock engine?? have to change head gasket and was thinking of doing some tweeking wile I was at it.
My 84 has 4;10 gears was thinking of putting Gearvendor unit on 727 is there any other stuff I can do to improve the 727 tranns? thanks for any help

 

[BushWakr - RIP]

CKnoop ,



Welcome to the asylum, pull up a chair, and the medication will come around soon..... :-laf :-laf



You can set your pump timing to 15-17* advance or roughly 1. 45-1. 55mm lift (depending on who/how it is set. )

Fix the head gasket, if that needs doing, before you do any performance adjustments, otherwise you'll be doing the gasket at an inconvenient time. .

If you are towing any weight on long grades or driving at higher altitudes you may want to be conservetive with your pump uprates.

Generally though you can increase you "high idle" or top governed speed. Bring your governor screw back out about 2-3 turns and check with a tach. Most set them around 2900-3000 RPM.

If you've been reading the threads about AFC (diaphram) settings you can do that as well. Turn it to max setting.

The full fuel screw should be good to go atleast 1 full turn. Check EGT's before and after though. Always, always, have a baseline to work from. Use the same test conditions, hills, speeds, RPM's etc.



As for the transmission you can get a full service done, have the valve body bolts loosened 3 turns each and that will allow more oil to drain out than is held in the pan. Retorque the valve body and fill as normal. While the pan is down, have your idle line pressure increased to about 58-60 psi, and your WOT pressure set to about 110 psi.

I don't know what the "cost effectiveness" is when comparing a fully rebuilt A518 (has OD) to a Gearvendors unit is.

Personally I'd save my bucks and have DTT build me a transmission properly rather than try to use a gearvendor to get around a shortcoming like you sitution.

BTW, re setting your governed speed to about 3000 RPM will help with your top end a bit too.



Well that's a start, ask away, and we'll all try to pitch in around here... .



Regards, Bob.