Nailhead Guys...Need A Shorter 401 Water Pump...What's Available??

Well as I am installing a '61 401 into my '61 Skylark I am tight on room. The water pump seems to be excessively long. It seems to be needed because the engine was AC and power steering and has a 3 groove pulley.

I need space and I saw somewhere that the '62 and up pumps and timing cover could be used. Is this true?? If so what is the difference?


Any bit of help would be greatly appreciated! I want to drive this damn thing!!!!!


Thanks,



******Knuckles

 

I had the same problem with a 401 fitting into my '55 Special. I wound up locating a '59-'60, '61 w/o A/C pump, Buick p/n 1396562. It measures 6" from mounting surface to fan mounting surface of the flange.

There is also a shorter pump, p/n 1396563, which is only 5" long.

Hope that helps.

 

sorry I'm a slacker... Haven't been able to find the box with the others in it.

 

Dude, no problem. I'm just getting real close to needing a solution.

Let me know.

Thanks,


******Knuckles

 

Do you know if you need a different timing cover? I was told by a few that it may be needed.

Thanks,


******Knuckles

 

I didn't need a different timing cover on my '61 401 for the shorter pump.

 

What was the difference between the pump you had and what you needed?




******Knuckles

 

It was several years ago and I don't recall exactly, but I believe the original pump measured 7" or 7-1/2".

 

Thanks man. I check mine tomorrow.



******Knuckles

 

My water pump measures 5 1/2" from the front of the timing cover to the snout of the water pump and 8" to the block.

What do you think?




******Knuckles

 

I'm pretty sure that's the shortest one they made.

 

And his is still pretty long. Waste of space from what I seen.

 

I'm not sure what my pump is, but it is new. I also know that there are two different designs of timing cover. I know this because my pump and cover don't match. I ended up making an adaptor plate between the two.

 

I recall having a similar problem on my 401. How much clearance do you need? I needed a little less than 1/2". I ended up pressing the fan mounting flange on further on the shaft. I only was running one belt for the generator so the pulleys lined up. Are you running the stock fan and spacer, electric?

 

I like the idea of pressing on the fan mount a bit more.

I will run the mechanical fan for sure.

Here is a few pics of my issue;





What I'm pointing at is the lower radiator tank bracket;






******Knuckles

 

Not sure if it's too late for you, but when I built the '65 401 for my model A, I ordered a pump from Napa, and it measures a SHORT 3&5/8 inches from mating surface to timing cover to flange surface (not including the shaft, which is approx.1/2 "). Didn't save the box or the part #, sorry. Hope this helps.

 

What could help is to run a Hayden brand fat, stainless blade fan in the diameter you want.

Reason you want a Hayden is that the blades are set back of center fan hub.

A same diameter Derale fat, stainless blade fan I have has the blades centered on the fan hub.

If I remember right you'll gain 1"-1 1/2" additional clearance.

 

These pics of a 15" diameter Hayden fan on my 31 on 32 rails roadster may help to illustrate.

My 32 has the same style Hayden fan, but is 17" diameter.






These additional pics show how long the short 455 pump is.

 

I'm sure you looked/measured but, can you move the engine 'back'?

 

According to the book, How to Build Max-Performance Buick Engines, the small displacement blocks share many components with their bigger brothers. The following parts swap from any Nailhead; timing cover, heads, distributor, oil pan, and exhaust.

 

Guys, thank you so much for all the help and pics.

As for setting the engine back, I have chose not to cut into the firewall. I have it about a half inch of clearance betwwen the engine and firewall.

I still may cut into the radiator support and push the radiator forward.

We'll see soon.

Thanks again,



******Knuckles

 

57-58 short pump, 59-60 long pump, 61-66 short pump, measures 6 1/2" from front of block to front of pulley flange.

Measured on a 66 425.