Engine temp rises when I get to cruise speed

[hotrodcbx]

I have a similar setup, blown 286" flathead. The first thing I would suggest is put a boost retard system in. If you are running only 18 d total that is not enough for the times you are NOT on boost, which is probably most the time. I also don't see the need
102 octane, I run 92 with no problem. I have 12 d initial, 14d centrifigal for a total of 26d.
The boost retard control can be adjusted for anywhere from 1 - 3 retard per lb. of boost. I run mine at 2 d retard per lb of boost. At 5 lbs of boost this will retard my timing by 10d. for a total of 16d at full throttle.

 

[The Brassworks]

It'll be interesting to see if Brassworks "steps up" if you can prove their radiator to be deficient.

I'll try to "step up" . I talked to Joe V. again today and he is is presently gathering temperature data.

Incidentally, if you post on these forums and do not get a reply from us its because we do regularly not check them. I went on today because a recent visitor in a tour group told me the forum said we had closed. It turned out they confused us with Walker. We are not closed, just busy. Then I stumbled on this posting from Joe V who I have been talking to about his recent engine temperatures.

idle 180
60mph 205
30-40 mph 190
45mph ? but too high for Joe's taste

Background

• Rebuilt his blown '51 8BA flathead motor with a supercharger
• Removed the air pan which routes air through the core.
• Advanced his timing.
• Changed his thermostats from 180 to 160 to open earlier
• Changed his fluids to a higher ratio of water
• Removed the 16” SPAL pusher fan and replaced it with a puller fan and universal shroud

Comments not declarations (argue amongst yourselves)

1. All engines operate in a range of temperatures. People with flatheads tend to like 180 degrees all the time. There are a myriad of temperatures in an engine and a fixed target is hard to hit.
2. A flathead at 3,000rpm on the highway is going to run hotter than a flathead at 2,200rpm on the highway.
3. Superchargers add horsepower and horsepower tends to increase temperatures.
4. Air deflection panels meets the lower tank header and routes air though the radiator. This helps on the highway when air wants to go the path of least resistance.
5. Cool air passing a hot fin puts heat in the air. If the exiting air is trapped the result can be heat soak.

A one size fits all approach to manufacturing rarely fits anything.
I will use another customer's radiator as an example. It was brought to us to use as a pattern when the Chinese POS fell apart. When we built the copper replacement, we pointed out that his fan shroud provided was trapping ~16.489% of the airflow through the core at the perimeter and the 7” motor and aggregate blade area covered ~63% of the hole opening. The vertical plastic support that joined the blades had a 7/8” gap from the core. This customer sent us another identical fan and he elected to have us fabricate a custom shroud to capture the whole core fin area. We also built the fan out and added a ring extension to remedy the issue of trapped air at the blade perimeter. We always vent the bottom for high speeds and we don't use flaps because they look terrible. We generally use SPAL because they provide hi CFM, are extremely reliable and they're an honest company. In this case we used what the customer wanted.

pictures are provided to illustrate.

 

[jrvariel48]

Installed the gauge started the car. Temp rose to 180* in the driveway. Air temp was 86*. I went for a ride and it went up to 205* while on back roads. I got onto the hi-way and the temp stayed at 205*. I put the heater on high and the temp was still 205*
I pulled over for a quick temp reading:

With the temp gun I read 194* at top tank and 187* at bottom tank. 7* difference

Temp gauge in head read 200* and 185* at the water pump. 15* difference

I don't know if that's enough of a change, it doesn't seem like it to me

 

[jrvariel48]

I have a similar setup, blown 286" flathead. The first thing I would suggest is put a boost retard system in. If you are running only 18 d total that is not enough for the times you are NOT on boost, which is probably most the time. I also don't see the need
102 octane, I run 92 with no problem. I have 12 d initial, 14d centrifigal for a total of 26d.
The boost retard control can be adjusted for anywhere from 1 - 3 retard per lb. of boost. I run mine at 2 d retard per lb of boost. At 5 lbs of boost this will retard my timing by 10d. for a total of 16d at full throttle.

Are you saying the 18* is causing the high temps?

 

[KiWinUS]

Installed the gauge started the car. Temp rose to 180* in the driveway. Air temp was 86*. I went for a ride and it went up to 205* while on back roads. I got onto the hi-way and the temp stayed at 205*. I put the heater on high and the temp was still 205*
I pulled over for a quick temp reading:

With the temp gun I read 194* at top tank and 187* at bottom tank. 7* difference

Temp gauge in head read 200* and 185* at the water pump. 15* difference

I don't know if that's enough of a change, it doesn't seem like it to me

Joe I agree. Not even close to enough difference. Radiator should pull more temp out.

 

[jrvariel48]

Joe I agree. Not even close to enough difference. Radiator should pull more temp out.

Hopefully Brassworks will chime in!

 

[38 coupe]

I agree with all the suggestions to get the most airflow before condemning the radiator. You had acceptable cooling last year. Then you changed two things, the radiator and the fan system. Take the new fan system off and see what happens. It isn't fair to change two things, not like what happens, and blame one of the two changes without checking both.


In my experience fans are a trade off between low speed cooling and high speed cooling. A big fan and shroud can pull a substantial amount of air through the radiator when the car isn't moving. However, that same big fan and shroud are blockages to air flow at higher speed. I have done this exact experiment on both an F-1 and on my 53 sedan. In both changes to big fans resulted in better cooling at idle and higher temps at highway speed.

 

[Ol' Ron]

A retarded ignition can also cause overheating.
G

 

[flatjack9]

Are you saying the 18* is causing the high temps?

I agree that 18 deg of advance at cruise is not near enough. Should have like 25 or so. The boost retard I would think is essential.

 

[jrvariel48]

I agree with all the suggestions to get the most airflow before condemning the radiator. You had acceptable cooling last year. Then you changed two things, the radiator and the fan system. Take the new fan system off and see what happens. It isn't fair to change two things, not like what happens, and blame one of the two changes without checking both.


In my experience fans are a trade off between low speed cooling and high speed cooling. A big fan and shroud can pull a substantial amount of air through the radiator when the car isn't moving. However, that same big fan and shroud are blockages to air flow at higher speed. I have done this exact experiment on both an F-1 and on my 53 sedan. In both changes to big fans resulted in better cooling at idle and higher temps at highway speed.

I totally agree with what you're saying and a fan swap is next in line. I did however have the same problem when I had a pusher fan on the front.
Thanks Joe

 

[jrvariel48]

Ron & Flatjack, I have no problem installing a BTM. I wish I'd known about this sooner. I tried to play it safe with a lower advance timing number so detonation wasn't a problem at boost. I didn't know 18-20* total at cruise wasn't a good thing.

 

[jrvariel48]

The BTM is $650. This distributor is $550 but Charlieny will have to work his magic as they don't offer a Flathead version. I feel the cost will be worth it because it's more tunable than a btm.

https://progressionignition.com/

I adjusted my total advance to 21* this morning. I'm waiting for the temp to go up so I'm close to where it was yesterday at 86 degrees.

 

[Bored&Stroked]

Usually having more timing will help cool the engine - though obviously you need to worry about detonation and boost (and fuel quality)

When you're just cruising at a constant speed (say 60 mph), the throttle plates are only partially open and you're not generating any boost as a result - so having 24 - 26 degrees of total advance is just fine. Now, when you step on the throttle a bunch (say passing a car or having fun), then you'll generate boost - and only then do you need to pull some timing out of it. Obviously you'll need to experiment with the timing curve and boost control to achieve the "happy medium" that gives you maximum advance, yet is reactive enough to pull timing out before it detonates.

I'd probably start at 20 degrees of advance, then get the boost control map working . . . then slowly add a bit more timing in to see what the motor likes before detonation sets in. Also, make sure you check your AFRs - as I don't like having a 14.6 AFR on a blown motor . . .

Distributors: I like what I'm reading on their website - as long as they deliver what they say and it is reliable, and Charlie NY makes it fit, could be a great solution.

BTW: Did you notice that they do deliver a mechanical tach-drive version. Depending on what type of tach you have or want to run, this might be an option.

Best of luck!

 

[Ronnieroadster]

Installed the gauge started the car. Temp rose to 180* in the driveway. Air temp was 86*. I went for a ride and it went up to 205* while on back roads. I got onto the hi-way and the temp stayed at 205*. I put the heater on high and the temp was still 205*
I pulled over for a quick temp reading:

With the temp gun I read 194* at top tank and 187* at bottom tank. 7* difference

Temp gauge in head read 200* and 185* at the water pump. 15* difference

I don't know if that's enough of a change, it doesn't seem like it to me

Since the temp went to 180 just sitting in the driveway with the outside temp at 86 that's not good. The temp difference you discovered from top to bottom using the heat gun is showing there's an issue with the radiator design. The air flow across the tubes/fins on the highway should be dropping the temp more than what your seeing. I would expect a reading of 180 on the highway however since its already at that point just idling in the driveway there's no way what your working with is going to get better.

Understanding how the flathead exhaust ports are super heating the water in the block a difference of only 15 degrees is not good.

What I would do if you haven't already is set the initial ignition timing at 12 degrees with a total all in of no more than 25 degrees. Personally I have never used a boost retard I see no reason for it unless the boost your getting is going above 10. If you do not see any reduction in the driveway temp after doing this in my opinion there's not much your going to do with the radiator you have.
Ronnieroadster

 

[jrvariel48]

Usually having more timing will help cool the engine - though obviously you need to worry about detonation and boost (and fuel quality)

When you're just cruising at a constant speed (say 60 mph), the throttle plates are only partially open and you're not generating any boost as a result - so having 24 - 26 degrees of total advance is just fine. Now, when you step on the throttle a bunch (say passing a car or having fun), then you'll generate boost - and only then do you need to pull some timing out of it. Obviously you'll need to experiment with the timing curve and boost control to achieve the "happy medium" that gives you maximum advance, yet is reactive enough to pull timing out before it detonates.

I'd probably start at 20 degrees of advance, then get the boost control map working . . . then slowly add a bit more timing in to see what the motor likes before detonation sets in. Also, make sure you check your AFRs - as I don't like having a 14.6 AFR on a blown motor . . .

Distributors: I like what I'm reading on their website - as long as they deliver what they say and it is reliable, and Charlie NY makes it fit, could be a great solution.

BTW: Did you notice that they do deliver a mechanical tach-drive version. Depending on what type of tach you have or want to run, this might be an option.

Best of luck!

Makes sense B&S. I did put a little more advance in yesterday and went up from 18* to 21*. I didn't have enough driving time to see what was really goin on as I'm focused on the temperature problem at the moment.
Mt cruise air fuel is around 14.2, but that's on a flat road and that's not for very long. I'm as low as 11.3 when I step on it. The roads here in Jersey are hilly so you're always on the throttle to compensate. What I'm saying is that 14.2 number does not stay on my meter for more than a few minutes at a time without changing.

I spoke to Charlie and he said he's up for the task. I'll call Progression Ign. today to see what the deal is. I really like the idea of seeing and changing my timing on the fly. It would be great to change timing maps as you're driving without going back to the garage to mess around with springs etc. I haven't read anything bad. I know it's a newer technology, but I'm willing to take a chance. I can always go back to the mechanical distributor.

I did notice the tach drive unit for the corvette. I'm already set with the electronic tach which seems to work well.
Thanks Joe

 

[jrvariel48]

Since the temp went to 180 just sitting in the driveway with the outside temp at 86 that's not good. The temp difference you discovered from top to bottom using the heat gun is showing there's an issue with the radiator design. The air flow across the tubes/fins on the highway should be dropping the temp more than what your seeing. I would expect a reading of 180 on the highway however since its already at that point just idling in the driveway there's no way what your working with is going to get better.

Understanding how the flathead exhaust ports are super heating the water in the block a difference of only 15 degrees is not good.

What I would do if you haven't already is set the initial ignition timing at 12 degrees with a total all in of no more than 25 degrees. Personally I have never used a boost retard I see no reason for it unless the boost your getting is going above 10. If you do not see any reduction in the driveway temp after doing this in my opinion there's not much your going to do with the radiator you have.
Ronnieroadster

I agree Ronnie. I'm hoping that Lee from Brassworks is following this post and offers some technical comments, advice and solutions.

My initial timing is at 7*. I'll bump it up to 12* and see what happens. I'm still wonder about the shroud causing a problem at hiway speeds. As you said, if it's 180* sitting in the driveway, it sounds like a radiator problem
Thank you Joe

 

[Ol' Ron]

Charley's distributor, with an 8deg vacuum canister. Would give 28 degs in cruise, but only 20 at WOT. Should work, unless your static CR is too hi.
Gramps

 

[Gene1949]

My kid and I had pretty good luck by simply using an adjustable vacuum advance can connected directly to the intake manifold. Improved low speed cooling and much better idle.
At cruise (high vacuum) is functioned as it should giving you 6-10 degrees.
Under boost it dropped out; again depending on your setting of the can.
A 7* temp differential between the upper and lower tank is unacceptable.

 

[Bored&Stroked]

Over the weekend I did a couple tests: I increased my timing from 24 degrees total to 26. That was a bit too much - caused bucking and some detonation under heavy throttle in 2nd and 3rd. I put the timing back to 24 - all is well.

Temperatures: It was fairly warm over the weekend - about 85 degrees or so. I went to the Goodguys meet (about 20 miles away) - running about 65 - 70 mph on the freeway. My engine stayed at 180 degrees the whole time. When I came to the exit and it sat for a bit - temp rose to about 185.

I have a stock 32 style radiator with a stock fan setup - no shroud. I also have 160 degree thermostats with a couple holes drilled in them for bypass. I run mostly water, with a bit of anti-freeze to reduce rust deposits. I am also running Skip's water pumps with his improved vane design . . . though I think this is MORE of an issue with the older 37 - 48 pumps as the later pumps typically have the improved vanes anyway.

If it was mine, I'd pull the fan and shroud and set the total timing at 20 - 22 degrees (as a first step) and take it on the road. This will pretty much tell you whether the radiator has the capacity to cool the engine or not.

I like the idea of an ignition that is easily setup/tuned (I'm a computer guy) - with multiple tunes, though I don't believe this is your issue.

My guess, the fundamental issue is most likely overall cooling capacity and/or air flow.

 

[The Brassworks]

Hopefully Brassworks will chime in!

My experience with forums is that “chiming in” results in “piling on.” There are already too many declarative statements on here for me. I'll be brief.

When we spoke, I suggested you start by removing the fan shroud and putting the fan back on and measure under various conditions. It looks like you did not do that.

Do this first. If that lowers the temperature, then stop.

If you need more cooling I suggested adding the 1,959 cfm SPAL pusher that we mounted and you removed. The two fans should be mounted offset with the SPAL mounted higher and the cooling component lower. Better core coverage and I trust the stated CFMs of SPAL. You want the highest cfm where the source-sink differential is greatest.

You never mentioned the air panel had been removed. This I learned on the forum postings. Add it back. It's there for a reason, it forces air through the core at higher speeds.

We always recommend the largest core that will fit, pullers over pushers and pullers with fan shrouds provided you have adequate space. You purchased a 3 row core and I now see that a larger 4 row core core would have fit - I do not know why it was not purchased originally. The extra row of tubes and 33% more fins adds $100. The cooling components fan/shroud were added later at cost of $420 and they are blocking air. In fact, a SPAL pusher, SPAL Puller and the larger core could have been ordered, you would saved almost $160 and got far more cfm. It would have all fit in the space you have.

I cannot say unequivocally that the two fans will get your 1951 supercharged flathead to your 180 degree target because (1) the face area of a 1935 ford radiator is 17.5% less that the 1951 Ford OE core and (2) you have added a supercharger.

I can say that (1) the cores we design and make today are a marked improvement over what was available in 1951 (2) an extra row of tubes, more fins, more contact points and higher cfm from both fans with greater core coverage certainly would have helped.

I think you can get closer to your target without the fan shroud, closer still with a offset pusher/puller fan set-up. Do one thing at a time and record what you're observing before changing the next "thing".