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Offenhauser VS Edelbrock for 4 barrel conversion.

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POW Peter Wirth
HEBRON, NH - New Hampshire, USA   USA
That looks good though it is probably iron not aluminum. The angle looks fine. Good to see you are seeking ways to retain the correct coolant flow characteristics unlike some of the domestic 'complete' kits' that just plug the inconvenient thermostat by-pass at the waterpump.

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RossL Silver Member Ross LoMonaco
NJ, USA   USA
Is there a diagram of the water flow through the manifold, water pump, and heads/block?

darrellwalker Darrell Walker
Vancouver, WA, USA   USA
1966 Triumph TR4A "Christy"
1981 Triumph TR8 "Kate"
In reply to # 1507684 by RossL Is there a diagram of the water flow through the manifold, water pump, and heads/block?

I have not found one that shows all of the alternate paths. But if you keep in mind that the top hose flows into the radiator, and the bottom hose draws from the radiator, you can figure out how the coolant moves through the block, head and manifold.

TA Performance has this cover, but I don't think the output angle will work:

http://www.taperformance.com/proddetail.asp?prod=TA%5F1535

D&D has one that you can rotate the output:

http://aluminumv8.com/Home/NewStuff



Darrell Walker
66 TR4A IRS-SC CTC67956L
81 TR8 SATPZ458XBA406206
Vancouver, WA, USA

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Bergie Bob Berg
Powell, OH, USA   USA
Ross...the repair manual has the coolant flow diagram and search this website because someone sent a pdf of the repair manual book you can look at recently (look at my pic for carb tr8 w/ ac). ...also the thermostat housing does not have a bleed nipple only the bypass fitting which connects to water pump rear facing fitting...you need to either drill and tap the intake manifold or the top of thermostat housing...need the have the bleed back to expansion tank on fender well...also thermostat with bypass holes helps keep coolant moving (like a bypass) and pushing air bubbles past thermostat to bleed nipple and to the tank.....pm me if that doesn’t make sense...


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FE58261C-BF7F-480C-A577-7D787BBAB35B.jpeg    46.4 KB
FE58261C-BF7F-480C-A577-7D787BBAB35B.jpeg

rbaron Avatar
rbaron Roger Baron
Fort Mill, SC, USA   USA
Attached is a diagram of the coolant flow from the repair manual that I marked up for the Edelbrock intake.


Attachments:
CoolantFlow.pdf    145 KB

rbaron Avatar
rbaron Roger Baron
Fort Mill, SC, USA   USA
Bergie, you beat me to it!

Bergie Bob Berg
Powell, OH, USA   USA
Roger you should be published with your diagrams! The TA performance thermostat housing TA 1535 does not work in TR8 because orientation is 1’o clock vs 10’o clock...meaning looking from front of car at engine the radiator hose faces straight up slightly offset toward right side vs angled left toward pass side ..I have it the TA housing. ..too bad because its aluminum...

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POW Peter Wirth
HEBRON, NH - New Hampshire, USA   USA
In reply to # 1507617 by Pat.L As i posted above with emailing and posting with Bergie I tapped my thermostat housing instead of the manifold, from initial testing it seems to have cured my fluctuating temperature reading. I also change the thermostat to a 180 with by pass holes. Since the Edelbrock does not have the spot for the high speed fan sensor I moved the high speed wires to the sensor on the radiator and I can if I want set the low speed to run continuously. All this did was have the high speed fans come on around 197* instead of around 225*.

I do not know what tapping and adding a nipple to the housing and running a hose to the header tank would accomplish. Since it is on the backside of the thermostat, there would be virtually no flow until the thermostat opened any way and then really no point. I don't think in the long run it will make any difference with temp spikes and falls. I believe the only way to stop that is with the proper, as designed, thermostat bypass from the manifold to the pump.

As Darrel mentioned in post #48, the D&D housing will work. It's what I have, and after the initial shock of the cost fades from memory, it will just be another one of those things your car demanded and got. hot smiley

Bergie Bob Berg
Powell, OH, USA   USA
Petes correct ...you will get benefit not all you could....here is the math and hopefully it makes sense...if you do not have a bypass provision before the thermostat in the manifold or thermostat housing(ie edelbrock 2198 manifold housing in my pic) to the back of the water pump you get zero bypass movement....the provision ID of the bypass provision is 3/8inch (fits a 5/8 heater hose on OD) so the area is .11inch worth of coolant flow all the time.....if you do not have a bypass provision you get 0 inch coolant flow bypass and likely will have temp fluctuations on the gauge as coolant heats up before tstat opens/closes causing up and down temp readings..(original TR8 intake had a bypass built into the bottom of the manifold (see pic) and not part of the thermostat housing and with the edelbrock intake the provision for bypass was built into the thermostat housing as in my picture) ... .....if you have a thermostat that has bypass holes (high flow) drilled in it then you get .04inch of bypass (3 -1/8 inch holes =.04) so about a 40% increase which will help and push out air bubbles out of the system quicker and consistently ....having the air bleed before the thermostat helps because you have some back pressure that pushes them up and to the expansion tank and if the bleed is after (when you do not want to drill the intake manifold) you still get benefit because of the tstat by pass holes.....so Patrick get benefit and will see less fluctuation on the gauge and if it works your done.....starting new if you have a choice try and drill the intake-remember you can always take the intake to machine shop or fabricator who will have all the taps and expertise so your manifold doesn't break(what I do and best $50 you will spend) ....hopefully that helps...

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Attachments:
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t stat housing TR8.jpg

tr8 intake.jpg    44.3 KB
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POW Peter Wirth
HEBRON, NH - New Hampshire, USA   USA
As an aside to the whole by-pass deal, my arrangement (with the manifold to waterpump by-pass) does not utilize a small bleed hole in the thermostat. I'm not sure if the original did or not but my figuring is it is not needed when the Edelbrock manifold is tapped at the triangle for a bleed to the header tank, and a manifold to pump thermostat by-pass is in play.

darrellwalker Darrell Walker
Vancouver, WA, USA   USA
1966 Triumph TR4A "Christy"
1981 Triumph TR8 "Kate"
In reply to # 1507996 by POW As an aside to the whole by-pass deal, my arrangement (with the manifold to waterpump by-pass) does not utilize a small bleed hole in the thermostat. I'm not sure if the original did or not but my figuring is it is not needed when the Edelbrock manifold is tapped at the triangle for a bleed to the header tank, and a manifold to pump thermostat by-pass is in play.

The factory setup had all three, though the bleed from the manifold, besides going to the header tank, also went to the chokes on a carb car, or to cool the EGR (or warm the intake) on an FI car.



Darrell Walker
66 TR4A IRS-SC CTC67956L
81 TR8 SATPZ458XBA406206
Vancouver, WA, USA



Edited 1 time(s). Last edit at 2018-01-17 08:02 AM by darrellwalker.

Pat.L Avatar
Pat.L Patrick Ledford
New Wilmington, PA, USA   USA
A little more detail i should have mentioned earlier. I do have the water pump to manifold bypass. I did not wan to tap the intake manifold because I did not want to pull it and was hesitant of drilling and tapping my self, although I probably would have taken it to the machinist I use. After reading a lot of posts and what I did do I believe my problem was air in the system. By tapping the thermostat housing, bleed holes in the thermostat, filling the radiator with one of those sealed fill funnels I think the problem is solved. As I said I think the problem is solved, until the weather breaks I will not be able to tell if it run at a normal temperature.

Pow I believe you are correct and I wondered about tapping the thermostat housing and with out the holes in the thermostat I do not think routing the header tank house to the t-housing would allow air to escape until the thermostat opened.

In reply to # 1507867 by POW
In reply to # 1507617 by Pat.L As i posted above with emailing and posting with Bergie I tapped my thermostat housing instead of the manifold, from initial testing it seems to have cured my fluctuating temperature reading. I also change the thermostat to a 180 with by pass holes. Since the Edelbrock does not have the spot for the high speed fan sensor I moved the high speed wires to the sensor on the radiator and I can if I want set the low speed to run continuously. All this did was have the high speed fans come on around 197* instead of around 225*.

I do not know what tapping and adding a nipple to the housing and running a hose to the header tank would accomplish. Since it is on the backside of the thermostat, there would be virtually no flow until the thermostat opened any way and then really no point. I don't think in the long run it will make any difference with temp spikes and falls. I believe the only way to stop that is with the proper, as designed, thermostat bypass from the manifold to the pump.

As Darrel mentioned in post #48, the D&D housing will work. It's what I have, and after the initial shock of the cost fades from memory, it will just be another one of those things your car demanded and got. hot smiley



Patrick
1980 TR8 DHC TPVDV8AT209637
1957 TR-3 Under restoration TS20462LO
Western Pennsylvania Triumph Association
North Coast Triumph Association
TWOA

Darth V8R Avatar
Darth V8R Vance Navarrette
Beaverton, OR, USA   USA
1980 Triumph TR8 "Wedgie"
In reply to # 1507996 by POW As an aside to the whole by-pass deal, my arrangement (with the manifold to waterpump by-pass) does not utilize a small bleed hole in the thermostat. I'm not sure if the original did or not but my figuring is it is not needed when the Edelbrock manifold is tapped at the triangle for a bleed to the header tank, and a manifold to pump thermostat by-pass is in play.

The thermostat bypass hole is there simply to facilitate filling the cooling system. It lets the air in the system get past the thermostat when the engine is cold. The engine being cold is most likely when coolant will be added, and as we all know getting the air out of the system is important. That is why the bleed hole is to be located uppermost when the thermostat is installed.

As a side note, I tracked down the correct thermostat with the bleed and 'jiggle valve" when I rebuilt my engine. After a shakedown I took the car to get emissions tested, and it puked coolant out on the ground right there in front of the technician. It was on the verge of overheating all the way home. I pulled the thermostat and picked 180F thermostat up at my FLAPS, sans bleed hole. I drilled a 1/16" hole in the thermostat and installed it. Never had a lick of trouble after that. So getting the "correct" thermostat is not a necessity, you can just add your own bleed hole to it, and all is well. Cheaper too.

Vance



1980 Platinum Metallic TR8, navy blue interior
Bare metal respray, Crower cam, raised compression
ported heads, modified Zenith carbs, 0.060" overbore

POW Peter Wirth
HEBRON, NH - New Hampshire, USA   USA
A 180° is what I have too. The stock 190°, and with original FI specs of TDC at idle, and AC with it's condenser sitting in front of an already marginal radiator made for a car that ran hot most of the time. With the 180°, timing at 10° BTDC, and AC gone (never used it, could not see hauling it around for the sake of originality) normal temp is between 1/4 and 1/2. As far as the little hole in thermostat helping with filling initially, would not the tapped manifold accomplish the same thing? It is actually located a bit higher than any hole in the thermostat could be and only a couple of inches aft of the 'stat.



Edited 1 time(s). Last edit at 2018-01-17 10:29 AM by POW.

Mr. Nuts Avatar
Mr. Nuts Peter N
Tucumcari, NM, USA   USA
In 38 years of owning these cars I have never had the issues other people have with cooling systems. I have a hole in the thermostat, and a bleed line from the intake in the factory location to the coolant tank. I do not use special funnels, milk the system (what ever that means), disconnect hose, raise the front of the car, etc to fill the system, which others claim needs to be done. I simply fill the cooling system leave the cap off over night, refill it in the morning and drive the car. Done. The issue with any car with a radiator lower than the engine is to get the air out of the system before operating the engine. Since the cooling system fills from the lowest part to the highest, air needs to escape. The coolant tank only sits a few inches above the engine, the bypass hole in the thermostat is 0.125 inches, the bleed nipple a little larger. With the low pressure of the coolant only sitting a couple of inches higher than the engine and the small bleed holes in the thermostat and bleed hose it takes hours for the system to bleed the air out thru the coolant tank. Even then, I'm sure a little air is trapped on the ruff casting surfaces, corners in the system etc. You can try to improve what the factory did, but, it's not going to change the fact it takes a long time to get the air out of the static system.

What the factory did works quite well. Even when the engine is running it creates steam that need to be vented to the coolant tank. This has to be done at the highest part of the system or else it trapped. Other engines also have this issue to some extent. The new Chevy small block also has bleed lines, except I think they call them steam lines that vent to the radiator tank. One (use to be two) on each head as no coolant flows thru the intake. It's basicly all the same issue and solved in the same manner of air escaping from the highest part of the system. When you run the Triumph intake use what the factory used. When you run an after market intake mimic what GM did on their 215 engine as far as the cooling lines and thermostat housing. But, remember their engine sat lower than the radiator and trapped air was not a problem. So, you must run a vent hose off the intake manifold in the factory location (highest point). I've used the factory aluminum Buick thermostat housing (mentioned earlier on in this post) on the Rovers engines and Buick 231 engines (with a vent hose in the intake) I've installed and never had cooling issues. It's when people tried improve these systems or leave parts of it off that problems arise. Good luck with your project.

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