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End of the world 5.2L build issue

Mark Barnes

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So I decided to build a basic small block without any electronics, you know, JUST IN CASE. Started with a newly rebuilt 5.2L motor out of a '94 Dakota that got t-boned (by a cop, no less, but another story).
Anyway, it's been sitting in the garage for 15 yrs. or so with less than 10k miles on it.
Long story longer, I replaced the '94 timing chain cover with a '70's timing cover with the hole for a mechanical fuel pump. All good...until that made a 70's water pump necessary. Got the water pump set on there and quickly saw that the nose of the pump extended WAY too far forward to get the pulley to line up. The difference in pulley line up is +/- 2-1/2" or so.
I had intended to use the serpentine belt and pulleys, but it's beginning to look like a giant PITA. Looks like there is also going to be an issue with mounting the alternator too.
My questions are-
1. I'm sure others have done this before. How did you resolve the belt line up issue? OR, is there a water pump with a shorter nose?
2. Would it be a better idea to dump the serpentine belt idea, and go to a regular v-belt setup?
Thanks for any ideas. I'd like to finish my end of the world motor before an unnamed world leader decides the Ukraine is small potatoes and heads over here instead.

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Go to the v-belt. The magnum serpentine setup spins the opposite direction, so your water pump won't pump so well.
 
Usually a serpentine water pump pulley is smooth as it makes contact w the back of the belt and is driven the opposite direction. If you have a local machine shop, you can have a chunk of billet aluminum machined to reach back far enough. As for the older style pump. If it has straight vanes and an anti-cavitation plate on it, it will pump just fine rotating the opposite direction.
 
You cant mix and match early and late front components, it has to be one or the other. But you can spend a **** load on an after market serpentine set up.
 
You cant mix and match early and late front components, it has to be one or the other. But you can spend a **** load on an after market serpentine set up.
I've got an early water pump on my big block stroker w modern accessories and serpentine. Yes you "Can" if you know what you're doing.
 
You might want to check, but I don't think a 94 magnum had a cam eccentric for a mechanical pump.

Mark
 
You might want to check, but I don't think a 94 magnum had a cam eccentric for a mechanical pump.

Mark
You're right. I already put the Mancini eccentric kit on the front of the cam. Nice piece too. Thanks for the heads up!
 
I haven't done the magnum swap myself but I have looked into the magnum front end accessories because of the serpentine set up. The thing that stops me from going that direction is the lack of bosses on the la timing cover and additional bosses on the cylinder heads used for the magnum accessories. You may run into that being the issue more than the water pump.
For the water pump- I think you can just use the magnum pump and mag mechanical fan and you should be fine. It wont be as efficient as the full magnum setup because the mag timing cover is contoured like the mag pump housing, but the old LA cover and pump has non contouring at all, so you atleast have some flow direction with the mag pump. Make sure to trim the mag gasket so it doesn't get torn where the mag cover used to mate with it but the LA does not, or it will end up somewhere you really dont want it.
I would be cautious with using an LA pump with the reverse rotation of the serpentine belt. That may not work well at all.
That is, of course, my speculation so real experience would be better.
 
I magnum swapped my 69 Dodge wagon.

Mechanical fuel pump. Points ignition. .............

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Last edited by a moderator:
I haven't done the magnum swap myself but I have looked into the magnum front end accessories because of the serpentine set up. The thing that stops me from going that direction is the lack of bosses on the la timing cover and additional bosses on the cylinder heads used for the magnum accessories. You may run into that being the issue more than the water pump.
For the water pump- I think you can just use the magnum pump and mag mechanical fan and you should be fine. It wont be as efficient as the full magnum setup because the mag timing cover is contoured like the mag pump housing, but the old LA cover and pump has non contouring at all, so you atleast have some flow direction with the mag pump. Make sure to trim the mag gasket so it doesn't get torn where the mag cover used to mate with it but the LA does not, or it will end up somewhere you really dont want it.
I would be cautious with using an LA pump with the reverse rotation of the serpentine belt. That may not work well at all.
That is, of course, my speculation so real experience would be better.
One thing I did find out is that you can't use an LA water pump on a magnum timing cover. Impeller depth is deeper on the LA pump, so the pump ends up about 1/2" short of surfaces mating with the magnum timing cover. The other thing that is irritating is the LA pump has the heater core inlet/outlet on top, just right of center...right where the magnum one piece casting for A/C and alternator mount exist. You could probably do some creative carving and make it work, but I opted to go with the v-belt pulleys and mounting hardware because I found some cheap parts on Ebay.
All told, I had to secure LA power steering pump and mount, alternator and mount, and correct water pump pulley. Hope it's worth it!
 
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