Frankie the Fink

Is this a 'long' or 'short' water pump ?

wmf62

short
Bill

Frankie the Fink

The Vintage Air guy asked me the question and told me if there was about 3/4" between the front of the timing chain cover and rear of water pump it is a "long" pump. It makes a difference in what he orders !

wmf62

Frank
interesting... after the earlier thread on adding an alternator, and whether there was ever a 'lonnnnng' pump used in a corvette (JohnZ says 'never'), then it must be a short pump. besides it has the bypass fitting on the top....

what does it measure between the timing cover and the back of the WP?

if a long pump was never used, then why order an a/c setup for a long pump... pumps are easy to change.
Bill

wmf62

my LT1 pump from the 62
Bill

JohnZ

That's a "short" pump, but it's a Service replacement with a bypass, which was only used on the solid-lifter engines; the 250 and 300hp engines used a non-bypass pump.

The OEM bypass pump had a smaller diameter bypass fitting.

Frankie the Fink

I don't WANT to order long pump brackets if I have a short pump....so I don't understand the statement.

JohnZ

If you tell them you have a "long" water pump, they'll assume you also have cylinder heads with accessory holes drilled and tapped in the ends, which they use to attach their alternator and A/C compressor brackets. They have different brackets for use on Corvettes with the "short" water pump.

When passenger cars went to the "long" water pump in 1969, they also got accessory drive mounting holes in the ends of the cylinder heads, as the right-hand alternator mounting was an entirely new design (which was never used on Corvettes).

rene-paul

Try a 3782608 pump.
Brgds,
Rene

Frankie the Fink

Thanks all. Fixed it with the Vintage Air vendor; he's ordering the short pump stuff.