Just got this set-up & PO says it never got hotter than 190 on a hot summer day. I think he's full of it. This motor has the Hot Hemi Heads AN water crossover but is not running a thermostat. Their website says it will accept a Chevy thermostat. Guess what? Won't fit! This bipass is probably 8 years old- I wonder if the early ones were set up to run no stat or maybe a Chrysler stat? Car puked water constantly & was always full of air. No recovery tank so it marked a trail where ever it went. Here's what I took off. The cap was useless & wouldn't seat in that Moroso in line water neck. That's one of the reasons it pukes. There was 2 gallons of anti freeze in the trunk to top off where ever he drove. It runs a CSR 55 GPM electric water pump. Radiator is a custom built Griffin cross flow & mounted very low in car. I know there are inherent problems running a low radiator so I've been doing a little research. I found this on Jegs site & bought it. Then I chopped it all up to fit my application. Cut the flange off the bottom & tigged a plate to the bottom. Then drilled a hole in the side & tigged the water neck on it that was on the coolant crossover. This is what it looks like tonight. I had a new 16 lb cap I'll use for now. It's that cheesy one that shows the temp at cap. Surge tank also has a sight tube on the side so you can see if air is in system. Nix that cap- probably need a lever vent cap to manually get air out of surge tank to start. You can see how low the radiator inlet is. Other side of radiator has a petcock in top to bleed air. Here's the recovery tank I'll be using. Also has a sight tube. I'll mount on same side of engine as surge tank is. Lid is o-ringed & has a 1/16" hole drilled in the top to vent. I'll probably drill & tap the cap for a hose to the ground. Don't want a geyser in the face. So here's my questions. Everyone I talk to says to forget running a thermostat on a blown Hemi. Really? Does anyone know what the deal on my crossover is? Why it won't take a Chevy stat? I'm not opposed to replacing mine with a new one. Seems like a huge restriction in that crossover housing to me- even when opened (if it fit). What about running an inline filter housing in that piece of 1 1/2 tubing in upper rad hose going to radiator? Like this? The thermostat I have is a Stewart high flow that comes w/ 3- 3/16 holes drilled in it already. Will that work? Do I need a bipass while the thermostat is closed? Maybe not with the 3 holes in it. I thought of something like this. It's a marine stat housing that has a 5/8 bypass but where to plumb it to? There are no extra holes in elect water pump. This thing is pretty long so I probably will not go this route but maybe there's something else out there? I guess I could run the return to the plug in the Hot Heads blower intake or to one of the blocked off plates on back of head. Thoughts? What about those blocked off water ports on rear? I've read conflicting stories. Some say leave blocked off, improves flow through heads. Others said ran cooler when they ran a bipass on both front & rear of heads. So, which is it? Radiator has a shroud & a puller fan don't know CFM. Plans are to change it to a new shroud & 2300 cfm fan. I searched the cooling thread on Hemis but really didn't answer all my questions. So- what say you? AM I on the right track here? Suggestions?
I use the same (at least visually) crossover with a Chevy thermostat, not blown, but it runs 190 all day in my '51 Ford with a Walker radiator, Hot Heads heads, and BBC pump. Not much shine now 7 years later. The thermostat was no issue when I put mine together. Recollection is drilled an 1/8" hole in it, but not sure anymore.
I'd have to mill out the crossover on mine to even come close to fitting a Chevy stat in mine. Being it's an older model- who knows what it was set up to run.
I flushed the block of all the crap- replaced the freeze plugs w/ the SS ones from Hot Hemi Heads. Couldn't believe all the stuff that came out! Any opinions on running that Evans Cooling stuff rather than antifreeze? Damn- this system including the block must hold 5+ gallons! http://www.evanscooling.com/products/coolants/
Don't have any insight on the blown hemi. But if you wanted to find the right thermostat just go to a "real" parts store and ask them to find you one that fits, then you can get the one you want for the temp you want. If you wanna go the inline route just have those two parts machined in your picture. Hope that helps a little. Posted using the Full Custom H.A.M.B. App!
I'm nixing the idea of a remote thermostat. I think it should be closer to the engine, not 2 ft away. There's no stepped groove milled in the Crossover casting so I'm guessing this set-up wasn't for a thermostat. I'll probably just order the new one that accepts a Chevy stat- cheaper than taking the existing part & having a shop machine it.
I'm running a HH crossover (photos attached) with a 180* chevy stat on the supercharged 392 Hemi in my 33 Imperial. The cooling system has a Flex a Lite Black Magic 3500 CFM fan and a Meziere 50 GPM electric water pump. The outlets on the back of the heads are capped off. On a real hot day (90*+) in SoCal stop and go traffic the car never gets hotter than 195* and that's with the fan set to come on at 185*. IMO the optimum operating temp for a Hemi would be 185-195*. Using an infrared thermometer the normal inlet temperature on the 392 will range from 180-190 and the outlet temp about 30-35* lower. If you haven't done so it checking the cooling system with a pressure test might be helpful. You could have a bad cap, blown head gasket or some other glitch that's the reason for the overheating condition.
Bad cap- yes Blown head gasket- no. The problem w/ this set-up is trapped air & puking all over the ground. I talked w/ PO at length yesterday- Says never got over 185 if he ran elect fan as soon as engine started. If he let fan come on when thermostat called for fan to come on (don't know on & off temps right now)- it would get to 200 but come down when he drove at speed. Fan & shroud combo- I have no clue what brand it is or what CFM it is. Blade is 15" & a S type. Motor is a Unimotor & has 2 numbers on it- 30318 & 06226. Wire leads from motor are pretty small. I have a Spal 16" that's 2370 CFM on another car & it moves a lot more air than this motor does. I'm trying to eliminate any potential issues by changing things so I have a firm known base to start from. BTW- that's a very cool blower set up!!!!
If you are convinced that trapped air is the issue then why all of the concern about t-stats and fans ? If it is an air issue then you will need to figure out a method of bleeding the system at the high point of elevation. .
Went back & looked at the HH crossover. It has the step so a thermostat will fit flush w/ surface- I must be having a senior moment. However, the hole to accept the body of thermostat rules out the Moroso or Robertshaw balanced sleeve stats because the sleeve is too big to fit in the hole. Yes- this style will fit This style will not fit
I think air was the main issue w/ the current system. That's why I installed this at the highest point in system. And removed this. All the other concerns about thermostats & fans.......................... There was no thermostat in current system. Not even a restrictor disc. Nothing. As for the fan- I'm just trying to get everything right. Lots of stuff PO had done was pretty iffy.
"Says never got over 185 if he ran elect fan as soon as engine started. If he let fan come on when thermostat called for fan to come on (don't know on & off temps right now)- it would get to 200 but come down when he drove at speed." My 392 can idle all day long with the only air flow through it being that generated by the fan and never get above 195*. If its necessary to have increased air flow by having the vehicle in motion to reduce the temp, it would seem that the either the fan is undersized or the effective cooling area on the radiator core is too small. Regarding the air bubble I'm missing something in the equation. Assuming the system is fully charged with coolant as the coolant expands it is displaced into the make up tank. Where is the air coming from? On my radiator the pressure cap is at the top of the radiator off to one side and the makeup tank is just below it. When full there is at most a 1/4" gap between the level of the coolant and the pressure cap contact surface on the radiator. That gap goes away as the coolant heats up and is bled off into the make up tank so any air introduced into the system would have to be external to it. There is one other thing you might want to consider-the use of a cooling additive to the system. I'm using a 50-50 blend of "Purple Ice" and antifreeze. "Purple Ice" has a surfactant in it that coats the water jackets with a film minimizing the effect of the the tiny air bubbles that will occur when the coolant is exposed to engine heat and wants to turn to vapor. I've used it for years in my flathead engines which are notorious for overheating.
I have a couple of bottles of Water Wetter- maybe the same thing as the Purple Ice. No overflow tank- just puked to the ground. I'm installing an overflow tank. Pictures in 1st post. Radiator is a custom made Griffin aluminum crossflow. Core area minus the tanks is 21" wide by 19" tall. No cap but has a petcock at top of radiator opposite side of upper hose. 2 row 1 1/4 tube- suppose to have been built to handle the motor. I have the Griffin order sheet from 2006. Fan is where I'm focused now. The air deal- PO never took the time to bleed it out. Just topped it off & drove w/ the bad cap & pitted Moroso in line water neck. Most of the time it was parked. Probably a no issue- I tend to overthink things & want zero issues w/ the cooling system. Doing research- air seems to be a huge issue w/ a low radiator so I'm trying to eliminate every potential issue. Better to think this out on my 4 post lift now than on the road somewhere. Called HHH- Crossover is same design- hasn't changed in the 15 year run of part. Takes a standard Chevy stat- drill a couple of holes in the flat disc part to bypass air. The balancing ones will not fit & could block water flow from other head.
I agree with your concerns about trapped air.I built a really mild 402ci BBC for my Dad's '41 Willys project....The enormous custom built aluminum rad and electric fan combo should have been more than enough to never even let it get hot enough to open the thermostst in my opinion....BUT,the rad cap was lower than the front of the intake manifold,and he refused to get one of those inline filler caps like you're using,so he could properly purge the air from the system,and it got HOT every time he drove it....like cooking eggs on the dashboard hot! He got a tall housing similar to the one shown at the front end of your post,allowing the release of air and a proper cooland fill,and wouldn't you know it?The overheating went away. It always seems to be the simple stuff that bites us in the ass.I am a constant victim of it...lol Also,I agree that you are probably best to err on the side of caution and swap out your fan for one that will move enough air to start a hurricane....overkill is good in cooling system design.
http://www.jalopyjournal.com/forum/showthread.php?t=792719 I can't say what works and doesn't - but I did start the above thread that has a whole bunch of good info. As far as the bypass issue goes, if the engine had a bypass (hemi a did) its always a better idea to incorporate it back in. The BBC pump has provision for it. Your blower manifold has some provision or easily added provision for it. You could tap the manifold for the rear coolant area and run under the manifold for bypass. I've also heard the " no thermostat " for blown hemi. I don't agree and think its because its a pita to add a bypass with the blower manifold. If there's no tstat the system never uses the bypass anyway . My 0.02
To make sure there are no air bubbles i have loosened the rear block off plates and i always drilled a 1/8 inch hole in the thermostst housing.I ran a blown 392 in my 39 coupe (avator) for about 5 years and 7000 miles and no heating issues whatsoever.I think tuning is more of an issue than water pumps and radiators.If you can get to a chassis dyno shop they can find exactly what you have and what you need.For the money its cheap to save the engine and have piece of mind.Good luck and hope you get it figured out.
i just went through this same thing. if i ran a thermosat it over heated big time. i tried just water and 50-50 antifreeze also a high flow thermostat and wetter water with the same puking results. last fall i tried the morosso restrictors. it worked. with cool wisconsin temps i had the blue one in and it ran about 160. with the blue on a 80 degree day it ran about 220. i then put in the red restrictor and it now runs a max of 200 in stop and go traffic. i drove it up to automotion two weeks ago at around 3hrs of freeway speeds no problem. when i got into traffic after the show let out i was concerned it would over heat. it didnt go over 200 and this was basically idling for over 45 min trying to get back to the hotel. demonds be gone its cured. i did also try to gut out my thermostat with little luck. i just think the hole in the thermostat is too small and causes a restriction of flow. i hope this helps i see you want to run a higher pressure cap. dont do it. from personel experience i tried it with horrible results. the pressure got high enough to collapse the cooling fins destroying the radiator. if you run copper head gaskets use a thin layer of plain silicone on both sides. too much will cover the steam holes. the max pressure cap should be 6-8lbs. i run o-rings on my heads and found they work best at 8-9 thousanths above deck. 15 thousanths was too much for a water application. too much leaking. also use head studs. good luck
I had a car that had a low radiator, to bleed air from the system I would jack the front end way up and burp it.
Is that the motor/car in your avatar? If so the the engine is open and should shed heat like crazy, with a similar car and blown big block chevy i can putt thru traffic stop and go, stop and go and temp never hit 190, on the open road the electric fan shuts off. I would go looking at the basic tuneup, the idle circuits needs to be on the fat side of conservative, timing should be aggressive - 34, 36ish. It sounds like the engine itself is making more heat than it should. Most people retard the timing too much in a blower motor, with the timing retarded the sparkplug is fireing right on top of the [piston and that creates heat like crazy and the engine can't deal with it. I say this for something to think about if case you haven't considered it - it is obvious that you have doing all the right things and the results are inconsistant with what you'd expect. Another handy tool is a lisle #24610 radiator filling gizmo that lets you run the engine and 'burp' it to get the air out (be sure to plug it before shutting the engine 'off'), i had a willeys with BBC and it'd overheat because trapped air and water will quit flowing if there is air in it. I bought this gimo and it took the air right out no problem. maybe that is all you need.
Great thread, Im putting together a 29 Dodge with a blown 392. I may get flamed for this, but rather get flamed here than on the side of the road overheated, but Im going to run 2 radiators, the small one up front and a large crossflow in trunk, bleeding air will be interesting, I will have bleeders at highest points.... thoughts????
No. That car (the 32) runs 180 no matter what the outside temperature is. Spent a lot of time dialing that car in. The blown 392 Hemi is in my 41 Willys. To be clear- overheating issues are per PO. I witnessed the car puking all over my driveway. I drove it & it stayed at 180-185. Car had so many other issues, I parked it to get it all dialed in.
The HHH blower intake has a 1/2" plug on pass side- you can probably see it between the 1st & 2nd runner. The driver side has a sender installed in it. I do have a brand new Weiand BBC mech water pump that I could install & run the bypass to intake- I would need to figure out the pulley deal. Right now- a single groove pulley is behind the bottom blower pulley & a custom alt mount runs alt low just on top of frame. Not sure how lucky I'll get w/ the pulley lining up. That is an option- I'm not that crazy about elect pumps & this one is 7 years old.
There are identical bosses on the rear of the manifold, but not drilled. The HH timing cover or another with reliefs for the wp bolts and short bbc pump mounted on adapters will line the pulley up pretty damn close to where you need it.
I've read that thread (over & over & over) & a bunch of others you took the time to post. Great work. I have some ideas I may want to post in that thread later. Can someone explain this bypass deal to me? I'm having a senior moment trying to wrap my head around it. I'm assuming if stat is closed & system cool on start-up- the water will circulate from bottom of radiator into engine & having nowhere to go- will circulate up through intake & back to water pump? Is that correct? Does it matter which port you use on pump? Shit- I have all the parts- just need a pulley & a belt & maybe some shims. Another question.......... Elect pumps flows 55 GPM idle or running. What does a BBC pump flow at idle & wot? I see Stewart has some mech water pumps that move mega water (at a mega price). http://www.stewartcomponents.net/Me...PROD&Product_Code=41203&Category_Code=ChevyS4
What ever you do dont go over 32 degrees on the timing. And thats with race gas. 28 degrees on the street. If you run any boost over eight pounds I would be thinking about a msd boost retard box to prevent detonation. The timing suggested in a earlier post may work on a chevy but not a early hemi. A late model 426 can take more timing depending on the head used and fuel used. A call to bob at hh will confirm this. Consider the restrictors I couldnt be happier with the way my car cools. And its a cheap part to buy.
Take a look at this and this ought to clear up some of the flow rates. http://www.stewartcomponents.com/tech_tips/Tech_Tips_7.htm ( I went with the stage 2 pump for mine) The electric pumps shine like diamond in a goats ass on flow numbers at idle and low Rpms. After 2500 or so Rpms the fall short of mechanical flow mumbers. I've read some test that advertised flow of 55 is at no pressure and actuall more realistically around 40 gpm. The BBC pump's hose take offs both flow into the pump, they are on the suction side. In their factory application the center most opening was plumbed to the BBC intake and the offset one was plumbed to the heater core as the return. My thoughts on the bypass- oem style first. It's not ever good to dead head any pump. If you have a closed T stat and no bypass or heater core you'll be deadheading the pump up against the tstat. With a heater core, it's constantly sucking water out of the head or intake thru the core and back into the pump. Along with any air or steam. Now most heater cores have a take off feed at the rear or opposite the pump end, opposit the top radiator hose. Can you picture the cross flow of water just from the heater core. Some cores have water valves that stop this , some don't. The front bypass will be sucking water out of the front of the motor fresh off the heads and running it thru again. This ensures fresh flow across the heads. It brings the hottest of the water to the Tstat. Can you picture the flow? So with the hemi, and assuming there's no heater in your hot rod, what is the flow doing if their is no bypass? It's not circulating beyond the bleed holes. until the coolant at the T stat is hot enough to open it. What's the temp at the rear or center of the head? I don't know but I'd bet its one hell of a lot hotter than what under the tstat. I believe a t stat should spend a fair majority of its time closed cycling between open and closed and it does moreso on some engines. If it was open all the time the cooling and heating would need to be in perfect balance. Shedding exactly as much heat as being created all the time. Nearly impossible in a car with variables such as load, road speed airflow, traffic, WOT times. You could probably do it on a stationary piece of equipment. Getting the bypass flow on the front of the heads is pretty easy. Off the rear is a bit more difficult but certainly doable. Maybe it doesn't need it off the rear but it sure sounds good in theory. There's plenty of room under the hotheads blower manifold. The cragars or weiands don't have much but probably enough however there is no way to tap the coolant thru the manifold. It has to be thru the end of the heads. Just to reiterate what I said before - just my thoughts and I can't say what works or doesn't yet.
It's a little tight in back of heads for access. Here's pics of the intake. Drivers side- sending unit for water temp gauge Pass side 1/2" plug My thought is to tap in there with a swivel AN 90 so I can eliminate a fitting & get it low & run it to top of WP for the bypass. Then drill 1 or 2 3/16 holes in thermostat plate making sure holes are on top to purge air before stat opens. I remember seeing a pic somewhere on the HAMB running it this way using a mech pump for bypass. Can't find the damn thread now.
http://www.improvedracing.com/an-sw...egree-hose-end-to-male-npt-fitting-p-292.html This^ is my plan but I'm putting 4 of them and routing under manifold.
41 Willeys, that is going to be a challenge with that small radiator and being closed in. You might consider tapping into the rearmost waterpassage in the head by drilling thru the intake manifold. Then run lines from the waterpump into there and blocking off the inlet water at the front. By doing that the water will flow across the heads and transfer heat to the radiator. Right now, like chevy etc, you plumb the water into the front and remove it a couple inches away, you can almost touch finger by sticking a finger into the inlet and another finger into the outlet. They remove heat by convection. Lots of race engines plumb the pressure water into the rear of the cyl head and it flows across the head to the outlet. What heatrange sparkplug are you using? i'd try a -9. it'll make a difference.
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