Heater core replacement - Clayton Classics

Replacing a rusted out heater core in my 54 xk120 OTS. Moss Motors distributes a unit from Clayton Classics. There are two major differences.
First the new core is 1/2 inch thicker. I am assuming that by removing the 1/2 inch spacers on the fan motor that the fan will then be lowered enough for the blade to be attached to the impeller? They do supply new clips to use because of the thickness. Second item is that the intake and exit tubes are 3/4 inch longer than the original. Seems like this will be an issue and perhaps they need to be cut to proper size.
Has anyone had experience with this retrofit? Thanks – Tom

Does anyone need a heater core replacement. I can relate my experience as I now have this installed.

I am about to order a Clayton core for my '53 DHC so any tips or suggestions from your experience would be very helpful. Thanks

I was able to modify the one that I got from Moss motors to fit properly (about 1/2" thicker than original) but it may be better to order the smaller unit as described by the following message from Clayton directly:

The design of the element is different from the original and is a higher performance unit which allows better air flow and heat transfer. If the LE15-7J is slightly too wide at 3” then maybe the LE15-5J at 2.25” was the direct replacement for your heater element?

Thank you! That’s helpful and I’ll consider the smaller sized core.

I also purchase one of these heaters. The mounting bolts don’t even remotely match the factory 3 bolts. they are larger and far apart so that none of the original mounts can be used. Curious how others addressed this?

My bolts lined up perfectly but I had to make modifications due to thickness

My 140 OTS had 3 bolts in a triangle that mounted the heater to the bulkhead. Viart shows the same pattern, perhaps 3 inches on each side. The Clayton heater has 2 much larger bolts only that aren’t even close to the original. What I did was take the original powder coated top plate of the heater assembly and drill it out to mount the Clayton support bolts. Then the original 3 bolts fastened as original. Seems to work perfectly.

I have fitted a Clayton heater core to my 140DHC. I bought direct from Clayton - they sell a core designed for the 140, don’t know about the 120, it might be the same. Three bolts in a triangular pattern, as the original. With the new clips supplied with it, all fitted perfectly. The only downside was that the copper tails were slightly too long, but I cut them to the required length and reformed the bead with a beading tool. Perfect - the cast aluminium door casing and doors fitted perfectly. I fitted new door springs and handles bought on ebay. Coupled with a new motor, the heater now works very well.

Was this just the core and the longer clips? I replaced the entire heater with the new Clayton. If I had just used the core it would have not been an issue. Thanks!

Yes, just core and clips. I wanted to retain the cast aluminium front and doors, which were in excellent condition.

I did the same thing with mine as Roger and all worked perfectly

Being fussy, the copper tails that stick up through the bulkhead were too long - the heater valve was left sitting too high to close the bonnet. I cut them back and used a bead-former to reinstate the bead.

I cut mine back also but went without the bead (no bead former) and all worked well

My motor was also fried and given that it’s basically not seen I went new. I do however have the lower section with doors and handles all restored and ready to go. I am going to try to fit that to the new core. It should actually fit.

Don’t see why it wouldn’t. I fitted a new motor as well, quieter and much more powerful.