Engine running temperature with mods

[Austin Healer]

One of the things we learned when making some LAT vents in steel is the shape of the inside of the aperture. Cutting back into the sub-framing and funneling the throat made a huge diff in the air expelling. Just sayin'

This is what is involved in adding the exhaust vents into a steel hood....

 

[sandy]

one thing is for sure... with a 180 thermostat, the engine can't possibly run cooler than the thermostat opening point... I would expect a running temp near 180 degrees with a 180 thermostat. that's borne out as you are running only 5 degrees above. another thing to consider is testing the thermostat to see when it actually opens vs. taking it for granted that the opening point on the box is accurate....

Not sure why so many folks have a problem with a 180F TStat, so many people worried about it but likely not much difference in cars with somewhat hampered cooling systems. The thermostat can never make your car cooling capacity better, just a different operating point IMO.

The LAT vents have such a small area I would not expect them to do much in the grand scheme of things. The Tiger radiator has about 290 square inches of openning, how much do a wide open LAT vent have? Not much. Don't forget all the rest of the ways air packs into the engine compartment besides though the radiator. Again, I think this is really the biggest problem as stated many times, GET THE AIR OUT! The Tiger Article is really good at a lot of the testing, not sure if it hits LAT Hood, been a long time since I have looked at it.

Once letting the air out is solved the next problem is the generally tiny radiator that the car has, but in looking at sizes of some of the early 65-66 Mustang radiators the Tiger is actually a bit larger area. That being said I had changed to a 3" thick Fluidyne stock size Mustang radiator and it worked really well except in the Summer at Willow Springs where in 100F+ temps the car ran around 210F+. Removed that and modified it to fit a larger core with side tanks, oddly from a 69 Camaro, but worked to keep track temps under 200. The issue I ran into with the Mustang on the street was no shroud and a small plastic fan would climb to 200 on a stop light while idling. The water pump bottom pulley was 'severely' under driver and also a big problem for the street. The Mustang doesn't have as bad a problem getting the air out of the engine bay as the Tiger but I think still the same, at speed the air can lift the back of the hood up an inch or so. I'm guessing hood vents would be a good thing on the Mustang for the same reason as the Tiger. I also had a few degrees of drop between old school green anti-freeze swapping to water wetter and distilled water, but not sure I would run only water wetter again. While it said friendly to aluminum, I'm thinking not so much, and sometining will needed to be done with iron motors (Mine is aluminum head/aluminum block) but the water pump had a steel impeller and guess what was rusty.

As to thermostats, I ran 180F with 3 3/16" holes (since no bypass hose) for some time, then replaced it with a restrictor in place with no real difference in on track temperature except a longer warm up but never ran cooler then with a TStat. Once I get the Tiger going will see what can be done to help besides what I have already done. The car does not have a fan shroud on, it has a Fluidyne 3 pass, an 11" Spal pusher and a 5 blade flex fan and a 19-22lb radiator cap (OK to do according to the folks at Fluidyne). Not the best combination, but it's what it is. Coolant for the Tiger is tricky, and again, may run a better brand of water wetter that has some rust and pump lube, but likely back to some anti-freeze. The coolant of choice for me after many hours of reading stuff on the interwebs was a Nitrite free coolant. I got the idea from my Aston Martin as it has an aluminum engine, and coolant is specfied as some odd stuff, but it's really Dexcool I think when all said and done. The main thing that I found is that anything with Nitrite or Phosphates can react with aluminum radiator and welds due to the brazing flux that is used in assembly. So ended up finding Shell Rotella ELC Nitrite Free, safe for Brass, Aluminum. All a crap shoot I guess.

If I could get a fricken spark plug boot on a plug I could keep the project moving forward (more on that fiasco later).

Sandy

 

[Carbuilder]

Updates.

My hood vents look like the picture that Austin Healer shows; sort of an angled cutaway in front of the vent.
I have tested the 180F thermostat that I had in the car and the 160F one that I am putting in. The 160F was a little sluggish, started opening at 160F and was fully open at 170F.

It's interesting about the air having very little area to exit the engine compartment. The extensive testing that was done by those 2 guys a while ago didn't mention that being an issue at all (unless I missed that part).

What I'm doing is not what should be done to see what effect each mod has. But I'm tired of taking things apart and putting them back together and just want to drive the car. So all the mods are being done in one shot; side air deflectors to direct more air into the rad, a bottom scoop to do the same thing, opened up the flow area into the rad, put a 160F thermostat in. It is not all back together yet, so no results, but here are some of the details.

First, a dumb one. The original rad opening in the sheet metal was round. I opened up the corners to increase the flow area. I recently noticed that the rad is blocked on the sides by over an inch each side. Why I didn't notice before? Don't know. Anyways, I opened it up more.
Before:


After:


I calculated a 16% increase in flow area. That should be significant.

Then, looking at the front of the car:


The red areas don't flow into the rad. They either flow through the horn holes, or if those are blocked then the air hits a wall and I suppose finds its way into the rad....somewhat.
The green areas flow through and out to the suspension area; no cooling provided.
What I did was make some angled baffles to direct the air going into those areas to flow into the rad.
Hard to get a good picture, but this is an upper one on one side:


This is after painting the upper and lower pieces. It is hard to see in the picture that they angle out at the front, as you can see in the unpainted picture. That was done on both sides:


These block most of the horn hole air. Some will go around the front/outer part of the baffle and go into the engine compartment; maybe some cool air in there is good?

The last area was below the rad. This area was blocked a little by the lower cowl metal and a lot by the licence plate. Can't really do anything about the plate. Well, I could move it over to the side of the front, but I really don't like that look on cars. So I made a "snow plow" to direct some of the air going under the car to go into the rad:





I've since painted it black so it really won't show much. And it looks low, but the oil pan and part of the exhaust is an inch lower.

I really think all this has to make a difference in cooling while the car is in motion. At idle, not sure how much good it will do. I did find a small area above the rad where fan air was blowing over the rad, so I'll seal that up.

It is 95F here so not a lot of fun working on the car.

Rick

Edit: I'm debating putting the A/C condenser back in, in front of the rad. It didn't seem to have much of an effect on engine temperature and if I don't put it back it will be another project to mount it under the trunk with a fan and connect it all up. The baffles I've added direct air to the front of the rad, which would largely be behind the condenser. I'll put the condenser in and have a look at what the airflow will be like.

 

[Austin Healer]

Updates.

My hood vents look like the picture that Austin Healer shows; sort of an angled cutaway in front of the vent.
I have tested the 180F thermostat that I had in the car and the 160F one that I am putting in. The 160F was a little sluggish, started opening at 160F and was fully open at 170F.

It's interesting about the air having very little area to exit the engine compartment. The extensive testing that was done by those 2 guys a while ago didn't mention that being an issue at all (unless I missed that part).

What I'm doing is not what should be done to see what effect each mod has. But I'm tired of taking things apart and putting them back together and just want to drive the car. So all the mods are being done in one shot; side air deflectors to direct more air into the rad, a bottom scoop to do the same thing, opened up the flow area into the rad, put a 160F thermostat in. It is not all back together yet, so no results, but here are some of the details.

First, a dumb one. The original rad opening in the sheet metal was round. I opened up the corners to increase the flow area. I recently noticed that the rad is blocked on the sides by over an inch each side. Why I didn't notice before? Don't know. Anyways, I opened it up more.
Before:
View attachment 21244

After:
View attachment 21245

I calculated a 16% increase in flow area. That should be significant.

Then, looking at the front of the car:
View attachment 21246

The red areas don't flow into the rad. They either flow through the horn holes, or if those are blocked then the air hits a wall and I suppose finds its way into the rad....somewhat.
The green areas flow through and out to the suspension area; no cooling provided.
What I did was make some angled baffles to direct the air going into those areas to flow into the rad.
Hard to get a good picture, but this is an upper one on one side:
View attachment 21247

This is after painting the upper and lower pieces. It is hard to see in the picture that they angle out at the front, as you can see in the unpainted picture. That was done on both sides:
View attachment 21248

These block most of the horn hole air. Some will go around the front/outer part of the baffle and go into the engine compartment; maybe some cool air in there is good?

The last area was below the rad. This area was blocked a little by the lower cowl metal and a lot by the licence plate. Can't really do anything about the plate. Well, I could move it over to the side of the front, but I really don't like that look on cars. So I made a "snow plow" to direct some of the air going under the car to go into the rad:

View attachment 21249

View attachment 21250

I've since painted it black so it really won't show much. And it looks low, but the oil pan and part of the exhaust is an inch lower.

I really think all this has to make a difference in cooling while the car is in motion. At idle, not sure how much good it will do. I did find a small area above the rad where fan air was blowing over the rad, so I'll seal that up.

It is 95F here so not a lot of fun working on the car.

Rick

Edit: I'm debating putting the A/C condenser back in, in front of the rad. It didn't seem to have much of an effect on engine temperature and if I don't put it back it will be another project to mount it under the trunk with a fan and connect it all up. The baffles I've added direct air to the front of the rad, which would largely be behind the condenser. I'll put the condenser in and have a look at what the airflow will be like.

The idea behind blocking the horn holes is to stop air from exiting them and being repassed back through the radiator. As there is little area for hot air to get out of the engine bay it's a high pressure area. This is only a problem at slow speeds or when the car is parked/stopped and idling.

 

[sandy]

I would guess they also add some pressure to the engine bay at speed as well, might not change cooling at speed but the less air in the engine compartment the better, let the hot air out

 

[Carbuilder]

Haven't driven the car yet to see how the improved cooling works. I did put a spring in the lower rad hose. Surprised how a fairly flimsy spring makes it so you can't squeeze the hose closed.



I put the 160F thermostat in, filled the cooling system and fired it up. Major leak, from the thermostat housing. When I reassembled it I thought it might give me a problem. The housing has 2 O-ring groves but is designed for a one-piece seal, sort of like the 2 O-rings joined together.



I previously bought a seal for the larger groove, and made one for the smaller groove. It sealed until I took it apart this time and used the same small seal; which didn't fit as well as the last time (some swelling it seems). I couldn't find a replacement one-piece seal without buying the complete housing. It seems like this is a leak point no matter what type of housing or seals you have. Someone said to fill the smaller groove with epoxy, machine it flat, and use a gasket. It seemed like a good idea and I was all set to fill both grooves. Then I saw how thick the housing is and thought why fill the grooves and then machine the epoxy flat, instead of just machining off the grooves. So that is what I did.



I machined it until the O-ring grooves were gone. I actually went a little too far before realizing the the black line you can see is not part of the seal groove, it is where the 2-piece housing it pressed together. I machined the recess for the thermostat and even found a gasket to use. A bit of sealant on each side of the gasket and with one warmup cycle, no leaks.

So the car is ready for a warm day without rain to test it.

 

[sandy]

I think I had one of the same or similar TStat housings. It was a really stupid design and it's really difficult to get the tstat centered in it unlike some of the others. I think I sent it back to Jegs and got a different one but couldn't use it as all of the ones I had got were not at the correct angle to clear the fan or oil filter housing. I ended up getting an old style ford aluminum one, chopped the bypass fitting and blocked. Perfect. I can't remember the brand that was really poorly designed, might have been March. Also watch out for the bypass hole in the gasket, on some of the gaskets it too large and overshoots the side of the housing! I think the ones from Felpro worked, the more generic ones with the sticker were punch with too large a hole on the bypass hole. Thought I posted that mess here but I don't see it, so I'll post a couple of pics...

Use some thick 4 ply silicone hose that I had from the mustang. The 90degree bend wasn't quite right but in forcing it, it caused more tension on the hose bend that prevents it from getting sucked in. It's a lot stiffer then the black rubber one that needed the spring. I don't know if the soft silicone would like the spring, so didn't try it.

One of the swivel TStat Housings, I think this was the March. it was really poorly engineered and not possible way to align in the TStat. And no, can't really glue it. or how would you swivel it...

Early ford aluminum housing, this one just uses a gasket. Bypass blocked, and good to go. The out of focus gray gasket has a HUGE bypass hole and on every tstat hosing it was either over the edge of the housing or so close to the edge that it would for sure blow out. Just badly engineering in China I guess.

This was the best billet one, single oring for not leaks, but alas wrong angle to work on the Tiger

Like a glove as they say

Each had a different angle, figured the Black March one would work, the middle is the Ford (maybe from a 62 something or other) and the best engineered one was the Mezerie.

 

[Carbuilder]

Testing with all the mods in place. The previous runs (testing with and without the hood vents) were with an ambient temperature of 75F and the engine temperature was around 187F. Idle was up to 198F.
The mods compared with that are:
Side baffles to guide air into the rad.
Lower scoop to bring air up into the rad.
Larger opening in the sheet metal around the rad (no blockage of the core part of the rad now).
160F thermostat in place of 180F
Spring in lower rad hose.

Did the same drive with an air temperature of around 77F (maybe not quite as humid). And the results...

Engine temperature was 170F. Yes! I set the fan to come on at 180F so of course it was not running. Almost a 20F drop in engine temperature.

I let it idle after the drive and it went up to 180F, fan came on, and was steady around 182F for about 3-4 minutes. I lightly rev'd it and held it at about 1800 RPM; I thought maybe the pump running faster and increasing the flow of coolant through the system might tell me something. Let it idle again and the temp was steady at 185F for several minutes.

So the idle temperature did lower quite a bit, and the driving temperature lowered a lot. I'm really pleased with this.

The A/C condenser is not in place and I'm going to mount it under the trunk with a dedicated fan. My car has the trunk floor raised so there is a lot of room under it to fit the condenser/fan.

Now if I could just get the fuel injection sorted out. I bought the relatively new Aces Killshot after reading a lot of good things about it. The price is very good, but it is a PIA to get properly tuned. Anyone considering it.....don't.

Rick

 

[Austin Healer]

Testing with all the mods in place. The previous runs (testing with and without the hood vents) were with an ambient temperature of 75F and the engine temperature was around 187F. Idle was up to 198F.
The mods compared with that are:
Side baffles to guide air into the rad.
Lower scoop to bring air up into the rad.
Larger opening in the sheet metal around the rad (no blockage of the core part of the rad now).
160F thermostat in place of 180F
Spring in lower rad hose.

Did the same drive with an air temperature of around 77F (maybe not quite as humid). And the results...

Engine temperature was 170F. Yes! I set the fan to come on at 180F so of course it was not running. Almost a 20F drop in engine temperature.

I let it idle after the drive and it went up to 180F, fan came on, and was steady around 182F for about 3-4 minutes. I lightly rev'd it and held it at about 1800 RPM; I thought maybe the pump running faster and increasing the flow of coolant through the system might tell me something. Let it idle again and the temp was steady at 185F for several minutes.

So the idle temperature did lower quite a bit, and the driving temperature lowered a lot. I'm really pleased with this.

The A/C condenser is not in place and I'm going to mount it under the trunk with a dedicated fan. My car has the trunk floor raised so there is a lot of room under it to fit the condenser/fan.

Now if I could just get the fuel injection sorted out. I bought the relatively new Aces Killshot after reading a lot of good things about it. The price is very good, but it is a PIA to get properly tuned. Anyone considering it.....don't.

Rick

Went through the FI ordeal as well... tried the Holley FItech unit... and had issues mostly with cold start and running. Now using a Motec unit. we ended up getting the most success using an intake with fuel rails and individual injectors. Still had issues with cold running tuning. Switched to injectors that extend further into the intake runners and had better results.... The mapping out for mixture is a ROYAL PIA

 

[Carbuilder]

I must have got lucky with the FiTech I had on a SBC. Installed it, fired it up, adjusted the idle, and that's all I ever did. Started, idled, and ran perfectly. The Aces is a very good price but so many people are having issues with it. Not quite ready to go back to a carb, but close. I'm going back and forth with customer support trying to sort things out.

 

[Austin Healer]

Testing with all the mods in place. The previous runs (testing with and without the hood vents) were with an ambient temperature of 75F and the engine temperature was around 187F. Idle was up to 198F.
The mods compared with that are:
Side baffles to guide air into the rad.
Lower scoop to bring air up into the rad.
Larger opening in the sheet metal around the rad (no blockage of the core part of the rad now).
160F thermostat in place of 180F
Spring in lower rad hose.

Did the same drive with an air temperature of around 77F (maybe not quite as humid). And the results...

Engine temperature was 170F. Yes! I set the fan to come on at 180F so of course it was not running. Almost a 20F drop in engine temperature.

I let it idle after the drive and it went up to 180F, fan came on, and was steady around 182F for about 3-4 minutes. I lightly rev'd it and held it at about 1800 RPM; I thought maybe the pump running faster and increasing the flow of coolant through the system might tell me something. Let it idle again and the temp was steady at 185F for several minutes.

So the idle temperature did lower quite a bit, and the driving temperature lowered a lot. I'm really pleased with this.

The A/C condenser is not in place and I'm going to mount it under the trunk with a dedicated fan. My car has the trunk floor raised so there is a lot of room under it to fit the condenser/fan.

Now if I could just get the fuel injection sorted out. I bought the relatively new Aces Killshot after reading a lot of good things about it. The price is very good, but it is a PIA to get properly tuned. Anyone considering it.....don't.

Rick

The 160 thermostat is probably the determining factor.... Yes, after your drive, the temp idling was 182.... which I would expect.... as airflow is less than optimal with the car stationary.... BUT, the 160 thermostat proved that the engine will run at lower temps..... as I predicted and as I have learned from experience....