Fuel Pumps and 2.8L motors

[Zack]

I was looking through some of the picture gallery\'s and noticed that some people are using mechanical fuel pumps. Any booklets etc. that I have ever read said that frame modifications were necessary to run a mechanical fuel pump in a smallblock s-10. Is this true?

Also, at my garage within the last few months, I\'ve pulled apart a few 2.8 liters and a few 3.1 liters. Every one of the 2.8\'s was all gunked up and caked up with disgusting almost solid motor oil in the heads. Every 3.1 liter that I pulled apart had perfectly clean heads. To the best of my knowledge (and I may be wrong) the 2.8 and the 3.1 are basically the same block, but the heads are not interchangeable. Could this oil problem be due to the oil return passages in the heads of the 2.8\'s? They appear to be smaller than the 3.1\'s. Every one of these vehicles also had oil changes at about every 3000 miles. Has anyone else experienced there problems?

[Mike]

on the mech fuel pump, i didn\'t have to mod anything, as for the 2.8 and 3.1, i don\'t know.

[fasrnur]

I too did not have to modify the frame to clear the fuel pump. I just put a Holley mechanical pump on and it was tighter than a stock replacement pump,but it fit!



As for the 2.8 and 3.1 heads...they are interchangable if memories serves me right.I sell them all the time.



Jeff....

[4more]

yup fuel pump fits fine



not sure on the heads could depend on the kind of oil that was used i have noticed some oils gunk up more than others

interchagablity might depend on year and induction system used i dont know

[stenaholic]

as for the fuel pump, i dont know since i have E.F.I. but all the guys seem to be saying it fits and for the heads i know that the 2.8 has overheating problems due to air pockets geting trapped in the water jackets inside the head which creates hot spot and blows head gaskets ect. thats why on i forget exactly what year but early 90\'s GM installed a valve to bleed that pocket when purging the cooling system of air after a flush. it is my conclusion that these hot spots may have cooked the oil to a thick gunk causing it to stick to the head. just another one of my conspiracy theory\'s or educated guess you could say

[S10gator]

the 2.8 i just took out had run completely out of water, had a hole in the front block freeze plug. I mean it was dry. that\'s the only engine that this has happened to of mine. replaced the plug, filled it back up and off it went, that was 20,000 miles ago. i\'ve never had the valve covers off to see if their gunked.



Jim

S10Gator

\'77 Vette

\'89 Jeep YJ

\'93 S10 350

[IceQueen]

Engine will fit fine with a pump. gm service bulletin on the 2.8 states that due to insufficent oil flow and high temperature do to pockets of hot gas or air causes the head to burn oil also causes the head to have a shorter overall lifespan which is why your probably seeing tar like oil deposits.

[bohn333]

i have seen countless engines that are gunked up with oil sludge. I don\'t mean to be bias here but its more or less oil preference. Every one of these engine were run with pennzoil in them , and they had the oil changed frequently. It wasn\'t just 2.8\'s it was SBC, SBF, and varoius other engines. Some were so bad you couldn\'t even see where the rocker stud entered the head. Yes 2.8\'s were notorious for bad heads, but i think the sludge was more or less an oil preference problem. I\'m not disrespecting peoples choice in oil brands. i just wouldn\'t ever use it in any engine i have. Thats just my 2cents.



And i only use havoline.

[drivin2fast]

I have to agree with you bohn... alot of it is oil preference... I have been running castrol syntec in my 2.8 ever since I bought it... I tore it apart a year ago and noticed alittle build up but none to speak of like has been said... and it had 250000 miles when I did the rebuild... nocking on 300000 miles now... and thats why I cant wait to get the SBC in it.. http://www.s10v8.com/images/smilies/icon_biggrin.gif

[MOREPOWER]

Any of ya people try Amsoil, little expensive but i never seen any build up on mine! http://www.s10v8.com/images/smilies/icon_confused.gif

[360hp350]

Im a valvoline man. Quaker State and Pennzoil are sh*t IMO.

[jdasla]

my mechanical did not fit....hits the frame....ive been asking questions...i may just beat the hell outta my frame with a 10lb. sledge hammer...or take the torch to it.

[evil_admin]

I use valvoline maxlife and half quart of marvel mystery oil. I too have seen 2.8s so bad that the rockers are covered and seen others where the gally was full of sluge.



My current 2.8 has always had its oil changed on time, well maintained and its heads look very clean. There is some sluge buildup but very little. IMO, its all in how you take care of em. I amways change oil when its 3000 miles, 3 months or when its nearly black. I do this on all my engines and they dont have more than normal buildup.