866 Endt Fuel Pump Timing

[hawk2881]

well lets start by saying i hope i am posting this right....

I have a V-8 866 ENDT, i would like to know how to adjust the fuel pump timing. I read a deal on here and it said I could maybe get 425 hp, but i have no idea how to do it. I have called several shops around the area and the guy's did not even know what a 866 was so i just told them i had the wrong number. I would really like to give my old truck a little more power. It is pulling VERY heavy loads out of the mountains, and 45 mph on the high way is a lil to slow. I really like this old truck it was my grampas trk and it only has 356000 miles on it and looks as if it was on the show room floor yesterday. So if any of you know what a 866endt is please point me in a direction. Oh you might need to know it is a 1974 RS700L mack 10 speed heavy front axle and mack rear's. this truck is super sweet and i dont want to junk it cause it to slow. Or What other engine options do i have will a 400 cummins bolt in fairly easy? thank you all that took the time to read this.

Jeremy

Deer Park washington.

[ThaddeusW]

well lets start by saying i hope i am posting this right....

I have a V-8 866 ENDT, i would like to know how to adjust the fuel pump timing. I read a deal on here and it said I could maybe get 425 hp, but i have no idea how to do it. I have called several shops around the area and the guy's did not even know what a 866 was so i just told them i had the wrong number. I would really like to give my old truck a little more power. It is pulling VERY heavy loads out of the mountains, and 45 mph on the high way is a lil to slow. I really like this old truck it was my grampas trk and it only has 356000 miles on it and looks as if it was on the show room floor yesterday. So if any of you know what a 866endt is please point me in a direction. Oh you might need to know it is a 1974 RS700L mack 10 speed heavy front axle and mack rear's. this truck is super sweet and i dont want to junk it cause it to slow. Or What other engine options do i have will a 400 cummins bolt in fairly easy? thank you all that took the time to read this.

Jeremy

Deer Park washington.

That is a real beautiful truck you have there. Are the drives on spoke or budd?

Well before you start fooling with the pump please realize the parts for these engines are very tough to come by. If you damage the engine or something fails then your SOL for parts in some cases. If it was your grandpas truck I would leave it alone. Just think of what your grandpa would say if you blew the engine up . I know I would run for the hills if I damaged any of my grandpas vehicles.

[fjh]

That is a real beautiful truck you have there. Are the drives on spoke or budd?

Well before you start fooling with the pump please realize the parts for these engines are very tough to come by. If you damage the engine or something fails then your SOL for parts in some cases. If it was your grandpas truck I would leave it alone. Just think of what your grandpa would say if you blew the engine up . I know I would run for the hills if I damaged any of my grandpas vehicles.

If you post a picture of the back of the fuel pump where the stop lever comes out I MAY be able to tip ya on a few tweeks. And I also agree with Thad on the Gramps truck thing ya don't wan't to go to far!A ten speed trans idicates to me it May be a 375 hp engine ya need to keep the rpms up a bit on these.

[hawk2881]

Thanks I really like her to.

It has budd wheels all the way around. and yes I do not want to go crazy turning it up. But I do not want to junk the engine while it still running. If i can not turn it up it is just dead weight i dragging from job to job with me and I would need to sell it.

I will get some pictures of the back of the pump today ASAP, it is raining very hard right now.

Thank you

Jeremy

[hawk2881]

here our some pictures of the back of the fuel pump. thank you for your time I have other pictures but they to big to post i can email them to you maybe. thank you my

my email

hawk281@hotmail.com

Edited October 3, 2009 by hawk2881

[hawk2881]

If you post a picture of the back of the fuel pump where the stop lever comes out I MAY be able to tip ya on a few tweeks. And I also agree with Thad on the Gramps truck thing ya don't wan't to go to far!A ten speed trans idicates to me it May be a 375 hp engine ya need to keep the rpms up a bit on these.

I have other pictures but they are to big what is your emial maybe i can email them to you. my email is hawk281@hotmail.com thanks

[BAD DOG]

That's a real nice looking R Model you have there. Endt 866 V8 , 866 cubic inch displacement 375HP at the ground if it's tuned up and running right it should already be around 425hp at the flywheel. I ran one daily until about 4 yrs ago, it would walk alover a 400 Cummins especially loaded an on a hill. I would be careful about the modifcations I made to one of those be cause most of the parts for those are extinct now, and those you might find still on the odd shelf are extremely expensive. I still have a lot of parts for those here, but I don't have any literature on them, I too did the trial and error thing with the one I had. I had mine tuned at Weingand Mack in Sterling Heights, Michigan, but Ted the service manager that knew Endt V8s like the back of his hand has retired. If your pump has never been messed with or off I would say leave the timming alone. 45 mph is that uphill and loaded or on flat ground and what kind of weight are you pulling, what's the gearing in it? I would say if it is geared like a truck and not a race car it should have no problem doing what you want it to, it's probably somthing simple wrong with an easy fix, are you keeping your RPMs up when working it they don't like to be lugged too much, it's hard on the bearings and they don't like to sit and idle for long periods of time. It would be a shame to get rid of it if it is such low milage and a family airloom like that. It looks to be in beautiful shape Good luck with it, and keep trying you'll get it figured out eventually.

[HK Trucking]

Sounds to me like maybe the puff limiter is stuck, not allowing the rack to open up fully.

Every one of those 866 engines that I've seen ran like hell.

I recall a time when I was driving a Brockway with a 425 Cat engine and a 13 speed, and another guy that worked with us was driving an R700 with a ENDT866 and 12 speed.

There was a long hill on RT 22 in NY state that had 2 lanes going up the hill, trucks were supposed to stay in the right lane. I was following the R700, we were both pulling Fruehauf trailer dumps loaded equally with bank run gravel. Going into the hill, I got on the Cat motor as hard as I could,and pulled out into the left lane to see if I could pass the R700. The Brockway pulled about even with the R700, and then it was a stalemate, I couldn't outpull that 375 HP Mack with the 425 Cat, and believe me, I was on that Cat motor for all it was worth.

.

[fjh]

here our some pictures of the back of the fuel pump. thank you for your time I have other pictures but they to big to post i can email them to you maybe. thank you my

my email

hawk281@hotmail.com

OK behind that 4 bolt tin cover you will find a jam nut 3/8 with and allen screw thru the center( I BEleive )If I remember corectly loosen the screws jam nut and turn the the screw out one half turn and lock the jam nut And give it a try for power Its been years since I been inside that style governer but, If that dont doit or reduces the power turn it back the other way 1 turn !

once you find which direction does the trick tweek as desired don't go to hay wire with the turns youll kill the thing!

[hawk2881]

Thank you all that have taken the time to help.

When I am empty tare wieght is around 40k it pulls the hills at 25-40 mph. it pulls the hill loaded around 20-25 mph, sometimes as heavy as 136,000 lbs, depending on the day it seems sometimes to very. I hit the hill at 1800 rpm everytime and it just dont seem to pull hard tell it gets down to 1300 rpm then it feels like i should shift down but that is when the engine sounds like it wants to run. My hired truck has a 400 cummins and i can almost keep up loaded but empty i dont stand a chance. his tare weight 37k.

how do i check or adjust the puff limiter?

Under the 4 bolt tin cover what is it I am adjusting? rpm, fuel delivery,or timing?

After I have thought about what you say about the puff limiter that could very well be a problem cause it not getting the fuel at top end. that why it seems to pull hard at low rpm? I am also now having some trouble with my pyro. what is to hot for the 866 endtb?

Thank you again I really like my truck I like pulling into the mill and everyone there has a new trk and then there is mine i post a pic of it when i can bet you will be able to pick me out.

[BAD DOG]

That sounds like my 866 would run HK , give a good ruuning 425 Cat a workout. The puff limiter could be the problem if it is still on it. I would have a look at the throttle linkage arm on th left side of the pump and make sure it isn't broke right where it pivots in the middle where the spring is on it I had that before. Check your whole throtle linkage make sure it will allow the rack to open up fully. Also the shutoff linkage on the right side of the pump , make sure it is pushed all the way forward they stick sometimes and it may not let it have full fuel and make it gutless I'd start with there before trying to open it up any it's a good chance it somthing simple. I speak from experience thinking it was something complex and my problem was right under my nose.

[fjh]

That sounds like my 866 would run HK , give a good ruuning 425 Cat a workout. The puff limiter could be the problem if it is still on it. I would have a look at the throttle linkage arm on th left side of the pump and make sure it isn't broke right where it pivots in the middle where the spring is on it I had that before. Check your whole throtle linkage make sure it will allow the rack to open up fully. Also the shutoff linkage on the right side of the pump , make sure it is pushed all the way forward they stick sometimes and it may not let it have full fuel and make it gutless I'd start with there before trying to open it up any it's a good chance it somthing simple. I speak from experience thinking it was something complex and my problem was right under my nose.

good call Bad Dog!

I totally agree with fhese coments and highly recomend checking them first before doing anything , the adjustment you will b making is the fuel delivery adjustment.

pictures of the front of the pump would be in order here to see if the puff limit is still operating!

[hawk2881]

ok on a mission for pictures of the front of the pump it is up in the woods and i am in moses lake so pictures wont be up tell monday or tuesday.

[dockmen027]

I recall a time when I was driving a Brockway with a 425 Cat engine and a 13 speed, and another guy that worked with us was driving an R700 with a ENDT866 and 12 speed.

There was a long hill on RT 22 in NY state that had 2 lanes going up the hill, trucks were supposed to stay in the right lane. I was following the R700, we were both pulling Fruehauf trailer dumps loaded equally with bank run gravel. Going into the hill, I got on the Cat motor as hard as I could,and pulled out into the left lane to see if I could pass the R700. The Brockway pulled about even with the R700, and then it was a stalemate, I couldn't outpull that 375 HP Mack with the 425 Cat, and believe me, I was on that Cat motor for all it was worth.

.

HK,

I hate to get too far off topic, but could this be one of the Brockways that you speak of? I understand this was one of several Cat powered Brockways (origional color) that pulled dump trailers up and down route 22 back in the day.

[hawk2881]

ok so about the puff limiter. I figured it out on my own with a little help from the service manuals. It was shimmed to tight acording to the book specs. It has helped, it now runs about 2200 rpm insted of 1800 rpm. The nut under the tin cover that I am to turn about a half turn I turned it a half turn tighter as well. What does that adjustment do again? I did not get a chance to test drive it loader broke down on the hill and blocked all the big trk's in for the night. Does the puff limiter shims regulate rpm? or does the adjustment under the tin cover?

[BAD DOG]

2200RPM sounds about right for it 1800 set too low. the one I had used to like to cruise with it about 1900 to 2100RPM with a good load behind her. I wouldn't advise runnig it under load at 1300RPM too much although they do have alot of torque at the 1100 to 1400 range it's hard on the crank to lug the snot out of them. that's why alot of them went to the scrap at an early age. It was probably the turn of the screw you turned on the back of the pump that gave you the added RPM the puffer is for emmission purposes it's supposed to delay the opening of the rack to prevent smoking, alot of them were taken off and tossed back in the day. Hopefully it works for you probably won't know until you try it loaded. That 400 Cummins of your frinds might seem quicker than yours empty but you should mop the floor with him loaded. good luck.

[HK Trucking]

HK,

I hate to get too far off topic, but could this be one of the Brockways that you speak of? I understand this was one of several Cat powered Brockways (origional color) that pulled dump trailers up and down route 22 back in the day.

No, it wasn't that one, it was this one:

In this photo I had the Steco dump trailer hooked up to it, but most of the time it pulled an aluminum Fruehauf tub.

Back then,Colprovia had a whole bunch of Cat powered Brockways running 22, as a matter of fact, that one I was driving was ordered by Colprovia but then they didn't take it, so my boss at the time, Artie Clark, bought it. It was originally that dark blue almost black color like Colprovia trucks were. It was a 1976. In 1981 Art Clark Jr. painted it green to match the rest of the fleet.

That 1693TA Cat was an animal, even compared to the big engines of today.

I remember some of the guys that ran 22 back then, Jim Johnson, Carl "Shake & Bake" Ranieri, "Jughead" Rinaldi, Bill "Creepin'Jesus" Clark (the guy that drove that Brockway before I did), Albie "Midnight Rider" Biagiarelli (He was the guy driving the R700 I was racing up "Jackass Hill")

We usually hauled out of Domain sand & gravel in Dover Plains, and stockpiled at Clark's pit in Bedford Hills.

Lots of memories there.

.

[fjh]

2200RPM sounds about right for it 1800 set too low. the one I had used to like to cruise with it about 1900 to 2100RPM with a good load behind her. I wouldn't advise runnig it under load at 1300RPM too much although they do have alot of torque at the 1100 to 1400 range it's hard on the crank to lug the snot out of them. that's why alot of them went to the scrap at an early age. It was probably the turn of the screw you turned on the back of the pump that gave you the added RPM the puffer is for emmission purposes it's supposed to delay the opening of the rack to prevent smoking, alot of them were taken off and tossed back in the day. Hopefully it works for you probably won't know until you try it loaded. That 400 Cummins of your frinds might seem quicker than yours empty but you should mop the floor with him loaded. good luck.

Rev the engine up to max rpm no load it should reach 2100 rpm if it dosent the linkage should be checked the throtle lever on the pump is likly not going full stroke at the pump.

.

[Rob]

My 74 RL797L with an ENDT866B engine will run 2350rpm all day. It idles right at 650rpm steady.

If you crank the fuel, ensure you have a working pyrometer and use it. I purchased the last lower gasket set for that engine in Mack's worldwide inventory; There are no more available with the exception of having them custom made, ($$$). Hard parts are following the same path so try not to break things.

Rob

[ducky698]

This is an interesting topic, my 866 hunts at idle from about 600 to 750rpm, cant wait to get it back on the road now. Rob I believe there is still 5 pistons and liners in Australia.

any one know how well the dynatard works compared to a jake on a C15?

Grant

[BAD DOG]

ok so about the puff limiter. I figured it out on my own with a little help from the service manuals. It was shimmed to tight acording to the book specs. It has helped, it now runs about 2200 rpm insted of 1800 rpm. The nut under the tin cover that I am to turn about a half turn I turned it a half turn tighter as well. What does that adjustment do again? I did not get a chance to test drive it loader broke down on the hill and blocked all the big trk's in for the night. Does the puff limiter shims regulate rpm? or does the adjustment under the tin cover?

Have'nt heard from you for a day or two. How does it pull now?

[hawk2881]

My 74 RL797L with an ENDT866B engine will run 2350rpm all day. It idles right at 650rpm steady.

If you crank the fuel, ensure you have a working pyrometer and use it. I purchased the last lower gasket set for that engine in Mack's worldwide inventory; There are no more available with the exception of having them custom made, ($$$). Hard parts are following the same path so try not to break things.

Rob

hello sorry I have taken so long to get back to you all on this I have had a long few weeks up here in the woods grinding, it has been raining us out.

I did buy the parts to fix my pyrometer what do you think is to hot at a hard pull. and my 866 only runs 2200 free spinning and loaded about 2000 now. I turned the pump up one turn and put 2 .100 shims under the puff limiter and it really runs good now.

Let me tell ya this thing is a cat eating Cummings stomping big dog now. but there is one it cant seem to keep up with the new mack trucks they only loosing 5mph where all of us are loosing 15-25mph those things are crazy powerful and sound awesome when they pass ya, but I don't think I will see any of them out this deep in the woods for many years.

If i bought a mid 80's to early 90's mack truck is there anything that would compare to my 700, like the off road dependability and toughness of getting drug by a skidder or dozer every day, and still go straight down the road and pass DOT spot checks, or am i better off to look for another 700?

I can not thank all of you enough for the help

thanks again

Jeremy

mid mountain wood recycling

[HK Trucking]

............... and my 866 only runs 2200 free spinning and loaded about 2000 now.

Did you check the linkage from the accelerator pedal to the pump? Make sure it's pulling the throttle shaft all the way against the high speed stop screw when the pedal is floored.

If the linkage isn't moving the throttle shaft all the way against the high speed stop, then adjusting the high speed stop screw will accomplish nothing.

.

[Rob]

As Herb said your problem could be the throttle arm no making full travel. That arm is spring dampened and the springs do get weak with time. I'm not sure if it comes apart or not as I've always just replaced the assembly complete.

I would consider replacing this as preventative maintenance.

Rob

[hawk2881]

Have'nt heard from you for a day or two. How does it pull now?

Hello

sorry i been out int he bush for few days longer than i though. the old trk is running great i backed the fuel pump screw out one turn and it really came alive. I was reading what a few other people have wrote on here, and what do you think is to hot on my pyrometer? but it sure kicks ass now as long as 900' to 1000' is not to hot for her on the long pulls i think it would keep going up in temp if i kept my foot in it.