small drop in boost 237

[Freightrain]

Well, got the turbo dropped off Friday afternoon.  They looked at it, it doesn't look terminal.  They are going to give it the once over, new bearings/seals, check balance on shaft, etc.  Should have it back mid week.

I tinkered around yesterday with the pump.  I re-evaluated the linkage and checking WOT.  Seems maybe I found the issue.  I think the arm on the pump had slipped ever so slightly as I blocked the pedal down to the stop and pulled the bolt from the arm on the pump and I could move it just about 1/8" more.  Hmmmm.  I readjusted the clip on the end of the arm to pull it to match up with pump at WOT.   I had to install that arm on the pump from my motor as it was missing.  I didn't want to pound it one, but got it on about 3/4 of the way and snugged it up.  I think it just slipped a touch, so I re-snugged the pinch bolt.

We will see this weekend after I get it back together.  I know the fact that it only takes just a touch of missing throttle actuation to cause issues with boost/power.

[AZB755V8]

Had the same problem with my E9 pump. Never have had the pedal close to WOT with it turned up like it is. The pedal was great since I got the truck. After time the throttle became very touchy and finally on my way back from Canada it would not come to idle without pulling up on the pedal, a real bitch to shift, not good in the end few miles. My son got his foot under the pedal to help with each shift after we got off the interstate and to the warehouse, about 2 miles. The bellcrank clamp on the pump was real tight but it moved on the throttle shaft when moved by hand. At rebuild the bellcrank was not pushed on enough to engage the serrated teeth on both shaft and bellcrank and in the bolt relief groove and just off the end of the shaft. New bolt pushed in on the shaft another 3/16 inch, new return springs since I cut the originals thinking I needed more tension, all is good. 

Make sure you have the serrations in both shaft and bellcrank to lock together. Both are needed.

[Freightrain]

Mine has a sleeve between the arm and the shaft.  Makes it kinda difficult to get good "teeth" into either.  Not sure why it is that way but like I mentioned it came off my 673.   I tapped it on every so gingerly.  Don't know what I could damage if it pounded too hard?

I have a very serious return spring so it always gets back to idle.  I'm thinking of converting it to some kind of spring tension throttle.  That way I know it is WOT, but won't damage the pump from pulling too hard on it with a solid linkage.

Edited August 29, 2016 by Freightrain

[blackdog2]

Had a pressure drop & smoke after days lookin  and checking everything I was leaning on the left front tire and glancing at the engine I noticed the old style intake had a split in the seem change it all better!!  

[Freightrain]

Ya, looked at mine too.  Just to be sure.

[Freightrain]

Well I got it back yesterday.  Got it stuck on late last night and started it.  Sounds okay.  Going to take for a spin tonight and test it out.

Was told the thrust bearing was kinda rough from "material" that ran through oil.  Don't know, the engine was a real unkown factor.  The shaft is definitely looser to spin then before so I think the bearings might have been a bit snug?  He mentioned it was a bit carboned up and if it was a firetruck that might be true do to the fact it sat around and idled a lot.

Edited September 7, 2016 by Freightrain

[Freightrain]

Got it put on Tuesday night, took for a short spin on Weds night.  Everything seemed good.  I had a race on Saturday and it ran well.  It will pull 15# now, though not at 2100 rpm.  It tapers off, but down about 1600 or so it will max out at 15#, then as rpm creeps up, it will fall off slightly.  Runs well.  I think the extra "flat" I put on the pump has helped some with acceleration. I know it really bellows the black the first few gears, like I remember all 237's did back when.  Won't really get a mileage report til I go to Pittsburgh in a few weeks.  As long as it stays over 8 mpg I'm happy.

[Freightrain]

Well, did a little more tinkering on the fuel linkage.  Seems I still didn't have FULL throttle.  I was blocking the pedal down and adjusting the arm to fit the hole on the arm at WOT.  Well, that is all well and good, but the return spring is pretty stout and was actually pulling the throttle closed(due to flex in the throttle linkage coming from pedal).  So I was still missing WOT, even with the pedal down on the stop.   So I  readjusted it again so that even after hooking it up to the spring, it was still WOT.  WOW...what a difference>  Much more peppy, still only 15# of boost, but definitely feel a difference in power and acceleration.

I want to change a couple things.  Get a slightly lighter return spring then make a spring loaded throttle linkage that won't damage the pump at WOT, but have some give from being able to stretch a spring. 

Have to run to Pittsburgh again next weekend.  Kinda anxious to see how it does with a trailer on it.  I took it to a party tonight just to see how it runs.  I'm liking it. 

Edited September 18, 2016 by Freightrain

[j hancock]

Going to be a race truck for sure!  How is the trans holding up?

[Freightrain]

Seems pretty happy.  It actually doesn't rattle as much as it used to.  Strange?

Though after seeing so many post with much larger engines in from of one of these I'm a bit more relaxed about its longevity.

[Hobert62]

Almost seems like your more exited to drive the mack then the car.   

[Freightrain]

LOL!!   Did ya catch on to that LOL!!!!

Ya, it is kinda fun to drive now.  Sounds good, runs good.  My buddy made reference to the fact he has time now and will be starting to work on pieces to fix the bunk.  Yea!  I really hate the way the back of the truck looks with that wood on over the opening.  But, what was I gunno do?