DumpsterFire
Well-Known Member
Wanting to do a mechanical fuel pump on my stock internals magnum. Are these hughes snout extension a good solution for the fuel pump eccentric on a magnum cam? A quick look did show one person posting a horror story.
How reliable are snout extensions for the fuel pump?
- Thread starter DumpsterFire
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DionR
Well-Known Member
I've had one in my motor for years now. Only issue I ran into was because the cam can move forward, my double roller timing chain was tapping the fuel pump arm off and on. I was able to close up the width of the arm some with a hammer and stop the noise (I think).
Bobzilla
Well-Known Member
We have also had one in use for around fifteen years or so now with no problems at all and lots of street miles. Proper installation prevents problems. File fit where necessary to get everything fitting correctly and then assemble with red Loctite on the camshaft sprocket bolt and it will stay in place and work well.
I have seen a couple complaints about these coming loose, but in reality it was the camshaft bolt itself that came loose and that can happen without these adapters.
I have seen a couple complaints about these coming loose, but in reality it was the camshaft bolt itself that came loose and that can happen without these adapters.
Same here. Installed mine with red Loctite several years ago and (knock on wood) no problem.
remytherat
Well-Known Member
I used on a snout extension on my magnum to avoid having to use an electric fuel pump. It seemed like a great option.
When I got it, I realized it was an idiotic design. The eccentric is not located by any sort of key, it is just held in place by the tension of the cam bolt. What makes this especially bad is that since the cam is rotating clockwise, resistance placed on the head of the bolt by the fuel pump is pushing counter clockwise, working to loosen the bolt. It does seem to work, but it's just dumb.
That said, I slathered the bolt in loctite and slammed it in there because I had no other choice.
When I got it, I realized it was an idiotic design. The eccentric is not located by any sort of key, it is just held in place by the tension of the cam bolt. What makes this especially bad is that since the cam is rotating clockwise, resistance placed on the head of the bolt by the fuel pump is pushing counter clockwise, working to loosen the bolt. It does seem to work, but it's just dumb.
That said, I slathered the bolt in loctite and slammed it in there because I had no other choice.
junkyardhero
Well-Known Member
it's a real roll of the dice. likelihood is that it doesn't as that they were phasing them out by/around 87, and with it being TBI it would need hi pressure feed (i'm assuming).
rollers w/ snouts are rare as rocking horse ****
Bobzilla
Well-Known Member
Your kit may have been missing something or it was packaged with an incorrect key. The whole point of this kit is to extend the key so it does have something to register the fuel pump eccentric onto. Do you have any pictures of your install?
remytherat
Well-Known Member
The key locates the eccentric to the piece of metal that centers it. Has nothing to do with the key on the cam
Bobzilla
Well-Known Member
The key included in the kits is stepped. The small part goes inside the slot in the camshaft sprocket and camshaft itself, as well as the nose extension. Then the fuel pump eccentric goes over that and registers on the new key so that it should not spin. Then the camshaft sprocket bolt clamps everything together. When installed properly it works just as well as the factory setup.
So I pulled the engine and the 46rh today . I haven’t pulled the timing chain cover off yet but I do see that it has a cover with provisions for a mechanical fuel pump and a block off plate . Which leads me to hope that it might have a snouted cam .
junkyardhero
Well-Known Member
i don't think that moves the needle much, but the pump block off plate is promising. sorta? i mean, they didn't cast pre magnum covers w/o the pump provision-- or at least not that i've seen.
either way, that's a decent score!
mopowers
Well-Known Member
Aren't 90-91 360s roller LA motos? If so, it likely has the provisions for a mechanical pump. Is the motor carbureted, or fuel injected?
NoCar340
The Original Partstitute
Correct me if I'm wrong, but the 1985-'89 M-bodies were carbureted with mechanical fuel pumps. With the exception of the AHB (cop) engines, they also all had roller lifters. It would make sense that they'd just use the one LA cam blank, but then again I'm not a large corporation that pisses away money for no discernable reason.
I'm just one man that pisses away money for no discernable reason.
mopowers
Well-Known Member
That's right. That's how my '91 360 was too. It had a long snout roller cam with the LA timing cover and block off plate. I'd bet good money that your cam will have the longer snout for a mechanical fuel pump.
junkyardhero
Well-Known Member
mid to late 84 (so model year 85) was the roll out for the roller motors. i've seen 85 rollers, but mostly 87+ however, i don't know if that's just a function of my location. to my understanding trucks and vans got TBI in 88-ish the 318 for sure, i'm not 100% on the 360. but the cars didn't and stayed carb and the HD/Police/taxi E series motors stayed flat tappet till the end.
as an aside, i know that imperials (and maybe cordobas) got an early type of TBI in 81 (or so) and that was a whole *** kerfuffle of bad juju and a rush job that was basically a dumpster fire. apparently the "fix" was to tear it all off and put back on a carb. (lolz)
anyway, ma mopar being ma mopar it's one of those: ya never know till you open it!
I had an 85 ft ave and it did not have roller lifters.
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