351 Cleveland running hot at idle.

[delawarebill]

hemikiller... that was FANTASTIC info. had NO idea it worked like that. thank you is not good enough... a great thank you to you.

 

[Paul of MO]

What we do to fix this issue is to install a short section of pipe that fits into the brass restrictor in the block.

Thin wall .75 exterior diameter aluminum tube is a nice interference fit and because it bottoms out below the brass restrictions it can't fall out.

It sticks up .25 inch or so above the restrictor.

This allows a widly available Windsor type thermostat to work while still allowing the coolant to bypass the radiator when cold.

Basically makes the hole in the restrictor smaller and a little bit closer to the thermostat.

When the TStat opens it goes into this slightly smaller hole and everthing runs cool.

We can idle all day with a built cleveland and a stock radiator and never even get half way on the stock guage.

I can send picks as we are building a cleveland this weekend.

 

[SteveO_71]

If you dont want to be bothered trying to determine which restrictor plate to use with the Cleveland thermostat, West Coast Classic Cougar also sells 'modified' restrictor plates that once installed, the common windsor thermostat can then be used.

Both options seem like good ideas.

https://secure.cougarpartscatalog.com/waterrestrictplate.html?sessionthemeid=26

 

[Paul of MO]

This modified plate eliminates the cold start bypass function.

Removing the brass part can also be a pain in the butt.

This causes a 351c to take forever to warm up and idle nicely.

Pair this with blocking the heat passage under the intake and you end up with a very poorly manered 351c when cold.

The .75 ext diam pipe is available at lowes or homedepot for just a few bucks.

 

[mrgmhale]

hemikiller... that was FANTASTIC info. had NO idea it worked like that. thank you is not good enough... a great thank you to you.

I have seen this explained a few times in the past, likely from HemiKiller, actually. I thought this is a good time to grab some screen shots and text on the subject, as it makes a lot of sense to follow the recommended steps. I never know when such tid bits like this will be useful to myself and others.

HemiKiller, than you for sharing that info (again)..

 

[giantpune]

Does this one look like I got bit by the wrong thermostat? Rockauto listed it as one for a 351C. It doesn't look like it has the little doodad on the bottom.

 

[Sheriff41]

Does this one look like I got bit by the wrong thermostat? Rockauto listed it as one for a 351C. It doesn't look like it has the little doodad on the bottom.

View attachment 79559

View attachment 79560

Try this: https://flowkoolerwaterpumps.com/products/robertshaw-333-180-thermostat
You'll want the 195 degree thermostat.

 

[Stanglover]

I have been using the Stant t stat bought from RockAuto # 13468 or 13469. I'm not sure from my invoice which is the hotter temp, but I know I have at least a 190 in there without any overheating issues, even before I installed an 18" clutch fan. These do have a "hat" on them to seal off on the restrictor plate. They work just as well IMO.

 

[giantpune]

Try this: https://flowkoolerwaterpumps.com/products/robertshaw-333-180-thermostat
You'll want the 195 degree thermostat.

I already ordered the one from napa mentioned on the first page. Should be here in the morning.