Antique & Classic Cars Blog

On our last episode of It’s Not Done Yet?!, the V8-in-a-TR6 project was in want of a lower radiator hose–the prior stock radiator setup proving too small to cool a 3.5-liter (215 c.i.) V8 when it was designed for a 2.5-liter six. Having sourced a genuine 215 V8 radiator and had it rebuilt with a more efficient core, our next challenge was securing it in the engine bay.

Stock radiator, left. Buick 215 V8 radiator, rebuilt, right.

I’d done enough measuring to know that it would go in there, but not in the stock location, where the original sat between two steel box members and bolted to them via side-mounted brackets. The “new” radiator would have to sit further forward, ahead of the steel box sections in question. This meant new upper and lower radiator hoses and more fan spacing to keep it close behind the radiator for effective cooling.

Old radiator sat between box sections. New one sits ahead of them. Its bracket uses same bolt hole.

To keep things moving, I had some 4-1/2 inch studs machined to accommodate 3-1/2 inches of fan spacers (with a half inch of threads on each end to anchor into the water-pump flange on one end and hold four nuts and lockwashers to secure the fan clutch on the other). This wide spacing was to allow a little more room for the lower radiator hose, which, if run underneath the front cross-member, would need to make a tight “S” turn to get back up to the radiator outlet tube.

Old hose ran under front crossmember. New outlet tube emerges several inches higher.

With the old radiator, the lower hose needed to go under the front cross-member because of how low the outlet tube sat. The 215 radiator, in its forward location, has a higher outlet tube by maybe 4 inches–hence the assumed need for a wicked “S” bend in the lower hose. Probably should have pulled the alternator before making that assessment. With that hunk of metal out of the way, it became apparent that maybe the lower hose could, as commenter Gary J. had proposed, sneak between the steering rack and front crossmember for more direct routing. Using the now-too-short top radiator hose for a trial confirmed that that gap is adequate and almost perfectly aligned with the outlet tube of the new radiator.

Aha. New hose can run between steering rack and crossmember.

Contemplating S-bend in lower radiator hose, I spaced fan out 3-1/2 inches….

Now the radiator could go back toward the firewall as far as the space allowed, increasing hood clearance, reducing required fan spacing and making for a better looking layout. But … my custom machined 4-1/2 studs were too long for that. Fortunately, my shop like everyone else’s includes a hack saw, permanent marker, and clamping instruments.

…but with more direct hose routing, 2-1/2 inches will do. But I need another 1/16th inch because 2-inch spacer had shallow hole for water-pump shaft.

The new radiator routing freed up one inch, which meant removing the 1-inch spacer from the lineup and sawing about an inch off the four fan studs.

New stud length about an inch shorter. I took most of that off the water-pump-flange end so that the back of the stud is flush to the back of the flange.

Yet these older fan spacers often have a curious attribute: the hole into which the water pump shaft fits isn’t drilled to the same internal diameter over the hole’s full length. Such is the case with my 2-inch spacer. Enough of the hole was proper diameter to allow it to slide nearly all the way flush against the half-inch spacer (whose hole goes all the way through) and then the water pump pulley. But the hole then has a step where it narrows about a 64th of an inch. Even though that variation is small, the spacer would not slide past the step (fan spacers fit with close tolerance to the water pump shaft to avoid wobble). The result was a gap a hair under 1/16 inch between the 2-inch spacer as stopped by the “step” and where it needed to be to hold the 1/2-inch spacer and water-pump pulley snug to the water-pump flange.

Draw two disks on sheet aluminum.

I thought about just cranking the fan-clutch mounting nuts down hard and hoping the force would crush or smear the step back the required distance. The end of the water-pump shaft is beveled, however, meaning that the force against the step would push outward against the spacer rather than directly back against the step. I didn’t want to crack my 2-inch spacer, which I had driven a half hour each way to retrieve from a mid-’60s sedan at Sonny’s Salvage.

Clamp 1-inch spacer to two thin disks as template.

So… back down to the basement to fabricate something to fill 1/16 of an inch. Could have used four washers, but hey, why take a hack-looking shortcut now? Instead, I traced the fan spacer onto some sheet aluminum and cut out two disks with tin snips. Then, using the 1-inch spacer as a guide, I drilled four holes for the mounting studs and a center hole for the water-pump shaft. Took a little filing on the center hole and around the circumference to make it all clean and proper, but it worked.

Drill…

With a 1/2-inch and a 2-inch factory ’60s-era GM spacer, plus my two thin homemade disks, everything that spins to cool bolts snugly into place. If I can get upper and lower universal radiator hoses in the length I need, we are in business with a running V8 TR6.

…and file.

Spacers good to go. (Shown six pictures up fitted with 2-inch and 1/2-inch spacers on water-pump shaft.)

This entry was posted on Monday, October 1st, 2007 at 10:05 am and is filed under Car parts, Car stories. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.