Fuel pump pushrod question.

[69427]

I'm pulling parts off the old engine, and while taking the fuel pump off, I got reminded about the pump pushrod. I was wondering about whether they rotate like a lifter, or because of the lower forces involved do they just slide across the lobe?
It's been a few years since I last looked at that particular part of the engine.

 

[TimAT]

I think it rotates in the bore like a lifter. I've seen a couple of those lobes worn and had a hell of a time getting the pushrod out- either it was slightly mushroomed or bent.

 

[mrvette]

I think it rotates in the bore like a lifter. I've seen a couple of those lobes worn and had a hell of a time getting the pushrod out- either it was slightly mushroomed or bent.

:lol::lol: Figgers, for ME, they fall on the floor....


:suicide:

 

[69427]

I was cleaning off the gasket surface of the pump, and while I don't think I got any crap dropped into the "internal" spring area, I'd like to douche it with WD-40 or something to wash out any little gasket trash. The diaphram shaft looks like it's sealed, so, any problem with spraying this out?

 

[TimAT]

No reason WD-40 won't wet the area enough to float anything that might be in there, then blast it with shop air. I think I'd try that over brake cleaner that might attack the rubber diaphragm in the pump.

 

[Twin_Turbo]

I use seals it sealed for between the mounting plate, you know the steel plate that goes between pump & block. They are sealed so hot oil won't get at the pump. The pump will last a lot longer and you can simply put grease in the pump pocket to lube that side.

 

[TimAT]

Unless that aluminum block is different than the iron blocks, there's only a hole with a 1/2" pipe plug under the pump. No plate on a BB-- AFAIK

 

[big2bird]

I was wondering about whether they rotate like a lifter

Yep. They have the same circular wear pattern on them when you take them out.

 

[Twin_Turbo]

Unless that aluminum block is different than the iron blocks, there's only a hole with a 1/2" pipe plug under the pump. No plate on a BB-- AFAIK

Yes, but it still uses a gasket and this thing is installed right there.

 

[TimAT]

That's quite the gasket setup. Looks like a lesson in how to spend $20 for a $1 part.
On the flip side, if the diaphragm in the fuel pump died, it would keep fuel from getting into the oil pan.

 

[mrvette]

Unless that aluminum block is different than the iron blocks, there's only a hole with a 1/2" pipe plug under the pump. No plate on a BB-- AFAIK

Yes, but it still uses a gasket and this thing is installed right there.

Uhh, dumb question but what's with them 'insulated bolts'...???

never seen such on any mechanical FP.....

:shocking:

 

[Twin_Turbo]

That setup is designed to keep heat out of the fuel pump so they use insulated bolts. The reason for the additional seal is to keep hot oil away from the pump.

 

[mrvette]

That setup is designed to keep heat out of the fuel pump so they use insulated bolts. The reason for the additional seal is to keep hot oil away from the pump.

:stirpot::hissyfit: Sounds like heading into the sublime already....wooden the CARB on top of that HEAT crossover lend a LOT more to fuel perk problems than some 'hot' fuel pump??

I don't understand something??

:sos:

 

[Twin_Turbo]

Remember, that stuff is not designed for your daily driver SBC, it's designed for a race car that goes full throttle roundy round and as such sees a lot higher temps there.

 

[69427]

New ARP pushrod.

I ordered a new pushrod the other day (an ARP, as it was the only name brand one I recalled seeing), and while getting it out of the package something seemed odd. I went to the old engine parts box and got the used one out. Yep, they're different, but not in size, only in weight. I put them on my trusty Harbor Freight digital scale and noted the weights. The original piece was 144 grams, while the ARP was 74 grams. Looking at it close it appears to be a capped tube rather than a solid shaft. It didn't mention that in the catalog description.
Well, while I wasn't purposely going for a weight reduction in that part, and though it's only a 70 gram reduction, I'll take it!