I bought a short block '84 351W for my Bronco some time ago and fitted it with Edelbrock Performer aluminum heads, Edelbrock performer intake, matching Edelbrock cam, and, of course, an Edelbrock Performer 1406 carb. I also went with an MSD ignition system - MSD Pro-Billet Distributor (mechanical advance), Blaster 2 Coil, and MSD 6 offroad CD ignition. I have a new stock water pump, all new hoses, and a new OEM radiator that has a 50/50 mix of anti-freeze & distilled water.

There's a 165 degree thermostat in the engine, but after about 30 minutes of freeway speeds, the coolant temp is up to 190 degrees. I know that's not too hot - but why isn't it staying around 165-170? I'm about 1500 miles into the break-in period for the engine. Also, I'm in Denver, so I'm wondering if the air is that much thinner that I don't get as much cooling?

Should I just switch to a 190 degree thermostat? Should I take the thermostat out and run it to see what temp it stabilizes at?

Any help greatly appreciated!

 

you should probably be running a 180 tstat. also a new motor until its broken in will run hot period. whats the timing set at? how do your plugs look.

 

Timing is set at 13 degrees BTDC. The plugs have a nice black soot on them... I know I'm running rich, but I haven't found a shop around here yet that will do a tune-up - but I'm still looking. I have the carb calibration kit - not sure which jets/rods to go to from the stock ones.

 

Sometimes removing the T-Stat will let the coolant circulate to fast and not cool. Making it run even hotter.

 

Hmmm.... I haven't run into that before.

One other thing I should mention though... The intake has a built-in rear crossover for the coolant. It came with an insert to block it off, but I never put it in - I just plugged the hole on the top of the intake. So - I presume coolant circulates through that rear passage?

 

did you get the head gaskets installed the right way.
and is the water pump turning the right way.......

I think those inserts you are talking about are for the exhaust crossover.

 

I think the water pump is turning the right way - it's belt driven off the crank pulley, so I'd have to twist the belt or something to make it go the wrong way.

I know the one's you're talking about - but those are on the heads. This is on the rear top of the intake.

HG

 

ok you can put the head gaskets on backwards......they are marked "front"

and all intake gasket sets come with block off plates for the egr port in the head/intake..I have never seen them made for water ports.

and last but not least the water pump......serpintine belt pumps trun CCW and V-belt pumps turn CW..if you mix them up the water pump is turning backwards......

 

They make 3 different Performers for the 351. 2 of them have the rear water crossover passage for EGR legal stuff. Of those 2, 1 is H.O. specific, and has an additional outlet beside the carb for the EFE valve. Dont know about the Eddy gaskets, but the FelPro's have provisions for the water, but need to be trimmed to properly fit the particular water port, to get good flow.

190*? That's just about perfect, IMO. I hear they got some big ol' hills in Colorado, and not much air to breathe, either. My guess is tune coupled with your thin air's it. You ARE running a tight-fitting fan shroud, right? Does it ping under load?



Pete

 

Well, without pulling the heads I don't think there's any way to know 100% that the gaskets are on right. But, since the engine ran at a reasonable temp all the way from Minnesota to Colorado, I'm going to assume the gaskets are OK.

The intake gaskets are on correctly - and I used "The Right Stuff" from Permatex in place of intake gaskets between the intake and the block.

No serpentine belts - so I think the water pump is good to go. I suppose even a new pump could have the impeller spinning on the shaft though. No bad noises to indicate that though.

Thanks for the feedback!

 

Yep. I wish I could tell you which one I'm using, but all my paperwork is still in boxes somewhere. I think it's the H.O. version though, 'cause the 'additional outlet' business rings a bell. I'll check when I get home today.

192* is where the OEM 351W used to run. I was surprised to see a 160* tstat recommended by Edelbrock, but I figured they know a lot more than I do - so that's what I put in. I'll try switching to a 180* and see what happens.

Thanks for the reply!