Can too little compression for a camshaft cause engine heating

[cjperformance]

Also while im thinking of it, does this vehicle have an X, Y or H pipe in the exhaust? I have had a few badly made setups over the years that have a pipe protruding in too far and blocking half or more of the exhaust flow to all or just one side of the system.

[Tuner]

IF my LM2 was worth a damn ( locks up off and on regularly ) I would say light load cruise AFR runs about 11.5-12.5ish @ 60 mph around 2650 rpm. If I slow down to about 50 mph and just cruise, temp comes off a bit and AFR hangs around 12.5-13+. ( I am very disgusted with this brand new Innovate LM2 as much as the car itself! )

Thoughts????
Top

Don't throw your LM2 under the bus, I think it might be trying to tell you something about the vehicle's electrical system.

How are you powering the Innovate? If it is a cigarette lighter socket it may be getting an insufficient or erratic electrical supply or ground. Cigarette lighter sockets are notorious for poor ground.

It is also possible a bad plug wire or wires can be causing EM interference. I recently used my LM2 on an engine that has copper wire (old school no resistance at all) plug wires and, no surprise, trying to use the induction clamp to get an RPM signal was an exercise in futility. A sort of usable signal was obtained from the 12V power to the coil + (HEI system) but it was unsteady.

When the induction clamp was on a plug wire or the coil wire, besides the erratic RPM signal, the LM2 would reboot about every minute or two, like the power had been interrupted, tho it had not been. I think it was overwhelmed by stray EMF from the solid wires.

I solved the power supply problem years ago by making an extension cord with a cigarette lighter socket and big alligator clamps from a discarded battery charger so the power supply is connected direct to the battery terminals.

Your electric fan that has a 60 Amp surge to start and possibly some other components in the electrical system could be causing a momentary low voltage condition which will make the Innovate re-start, similar to what using a starter motor does sometimes when the LM2 is already on.

Obviously, the cruise A/F is way too rich. Take a ton of jet out, use larger idle air bleeds, etc. If this engine will run on the lean side of stoichiometric it will cool down the leaner the A/F becomes, as long as your add suitable vacuum advance. On the lean side of stoichiometric the exhaust gas has unburned Oxygen in it and the overlap reversion improves the burn of succeeding firing cycles, instead of quench it like it does with rich exhaust which is high in CO (like it is now).

[topradman]

May we review what radiators have been tried?

I was just reading the section on Cooling at Stewart Components, tech tip #5 on radiators
http://stewartcomponents.com/index.php? ... tion_id=13

Double pass radiators require 16x more pressure to flow the same volume of coolant through them, as compared to a single pass radiator. Triple pass radiators require 64x more pressure to maintain the same volume. Automotive water pumps are a centrifugal design, not positive displacement, so with a double pass radiator, the pressure is doubled and flow is reduced by approximately 33%. Modern radiator designs, using wide/thin cross sections tubes, seldom benefit from multiple pass configurations. The decrease in flow caused by multiple passes offsets any benefits of a high-flow water pump.

A tall narrow nosed vehicle may be a very difficult design, needing very high pump pressure to provide cooling flow for multiple pass radiator cores.

The original radiator I built for this was a 2 pass, 3 rows of 1" tubes making the core 3 1/2" thick. With a 3 row x 1" tube core, the 2 pass is not highly restrictive at all. Out of desperation, I converted it back to a single pass and the cooling performed worse so I put it back the way I originally had it. I could see this "16x more pressure" being an issue if I didn't have the thickness that I have but I have previously built 3 pass radiators that were 4 rows of 1" tubes and had wonderful results on a couple of blown BBC 57 Chevys but I do not usually do 3 passes. Making a multiple pass radiator is an effort to squeeze more cooling out of a limited area to get flow velocity back up when your are forced to go thicker rather than larger in area and this scenario has worked out well for me in hundreds of applications. In fact, when you have room to go thicker and not larger with area, I have taken existing radiators that were already very thick and made 2 pass out of them and cured some heating problems by simply getting coolant velocity up in the tubing, thereby creating turbulence through the core tubing making the radiator more efficient with out having to change it's size.

The radiator core size is 20 3/4" x 17" x 3 1/2" which is the same frontal area as the 4 row brass core radiators found in 70 SS nova Big Block cars. Area is minimum I agree but should be enough based on a know factory application that did not have this much overheating issue. If there had been more room without cutting up the car, I would have put in more. My radiator is 1" thicker than the afore mentioned BBC nova and with 3 rows of 1" tubes versus 4 rows of 1/2" tubes and an extremely aggressive fan as compared to a clutch driven fan, I do not feel like the radiator, fan, water pump or any other portion of the cooling system should be inadequate.

41 WILLYS NEW VS OLD.JPG

This is the new one compared to what I took out of the car. This is a cooling test we did back awhile that made me conclude that we had an engine issue.

WILLYS REMOTE COOLER TEST.jpg

To help assist cooling flow, I have since upgraded the water outlet on the motor to 1 3/4" to match the water pump inlet and have upsized the radiator upper connection to 1 3/4" as well to assist in flow.

All mods to date have seemed to help but I really believe after degreeing the camshaft for information on what the heck it is, coupled with the lower compression of 8.5:1 ( or less?) that is all boils down to a mismatched camshaft for this application. I think the pig rich A/F ratios are over fueling the engine and making it ask for more timing still, just to help stay cool because I think I still have combustion going on and carrying late in to the power stroke where it should be finished. With cylinder pressures in the 150 psi area, I do not want to retard the cam and make it totally gutless so my plan is to get the A/F under control and see if I can lower the timing back a bit and get the same cooling results I am getting by having the ignition timing so advanced.

Does anyone know what kind of NOX reading is unsafe as far as a detonation indicator? The exhaust is so loud right now with mufflers off and with a solid mounted motor and lumpy cam that I am having a very difficult time telling if it is detonating. The header design also gives a weird exhaust note with mufflers removed and also makes it difficult to hear/feel possible detonation if it is present.

Also, if A/F is very rich, would NOX info even be usable for an indicator of detonation?

[ptuomov]

“With cylinder pressures in the 150 psi area, I do not want to retard the cam and make it totally gutless so my plan is to get the A/F under control and see if I can lower the timing back a bit and get the same cooling results I am getting by having the ignition timing so advanced.“

I didn’t mean you should necessarily leave the cam very retarded, just mean that you could use it as a test to see if the early exhaust valve open is partly responsible for the heat problems.

By the way, if it’s 90 and 180 degree exhaust blowdown interference, then I believe there’s an rpm range in which it runs well. That’s the rpm range for which the 180 pulse from the offending cylinder blowdown no longer has the time to make it down the primary and up the other primary before the victim cylinder’s exhaust valve closes. And for which the 90 degree offending cylinder has time to blow its wad before the victim cylinder intake valve opens. This rpm range is determined by the physical distance from one exhaust valve to another they the header primaries and the valve events.

[topradman]

“With cylinder pressures in the 150 psi area, I do not want to retard the cam and make it totally gutless so my plan is to get the A/F under control and see if I can lower the timing back a bit and get the same cooling results I am getting by having the ignition timing so advanced.“

I didn’t mean you should necessarily leave the cam very retarded, just mean that you could use it as a test to see if the early exhaust valve open is partly responsible for the heat problems.

By the way, if it’s 90 and 180 degree exhaust blowdown interference, then I believe there’s an rpm range in which it runs well. That’s the rpm range for which the 180 pulse from the offending cylinder blowdown no longer has the time to make it down the primary and up the other primary before the victim cylinder’s exhaust valve closes. And for which the 90 degree offending cylinder has time to blow its wad before the victim cylinder intake valve opens. This rpm range is determined by the physical distance from one exhaust valve to another they the header primaries and the valve events.

Makes sense. So cylinder 6 would tend to be the biggest victim of the bunch if exhaust reversion is a problem and cylinder 1 coming in 2nd ( if I follow you and assuming problem is compounded from one cylinder to the next in regards to 90 and 180 events.... passing it on )?
i.e. ... cylinder 2 reverbs to cylinder 8 (180), cylinder 8 reverbs to cylinder 4 (90), cylinder 4 reverbs to cylinder 6 (180)?

If I am understanding you correctly it would support this temp graph taken before any changes were made ( at least that I can remember ). This was before changing to a belt driven water pump though so coolant flow was static.

[topradman]

IF my LM2 was worth a damn ( locks up off and on regularly ) I would say light load cruise AFR runs about 11.5-12.5ish @ 60 mph around 2650 rpm. If I slow down to about 50 mph and just cruise, temp comes off a bit and AFR hangs around 12.5-13+. ( I am very disgusted with this brand new Innovate LM2 as much as the car itself! )

Thoughts????
Top

Don't throw your LM2 under the bus, I think it might be trying to tell you something about the vehicle's electrical system.

How are you powering the Innovate? If it is a cigarette lighter socket it may be getting an insufficient or erratic electrical supply or ground. Cigarette lighter sockets are notorious for poor ground.

It is also possible a bad plug wire or wires can be causing EM interference. I recently used my LM2 on an engine that has copper wire (old school no resistance at all) plug wires and, no surprise, trying to use the induction clamp to get an RPM signal was an exercise in futility. A sort of usable signal was obtained from the 12V power to the coil + (HEI system) but it was unsteady.

When the induction clamp was on a plug wire or the coil wire, besides the erratic RPM signal, the LM2 would reboot about every minute or two, like the power had been interrupted, tho it had not been. I think it was overwhelmed by stray EMF from the solid wires.

I solved the power supply problem years ago by making an extension cord with a cigarette lighter socket and big alligator clamps from a discarded battery charger so the power supply is connected direct to the battery terminals.

Your electric fan that has a 60 Amp surge to start and possibly some other components in the electrical system could be causing a momentary low voltage condition which will make the Innovate re-start, similar to what using a starter motor does sometimes when the LM2 is already on.

Obviously, the cruise A/F is way too rich. Take a ton of jet out, use larger idle air bleeds, etc. If this engine will run on the lean side of stoichiometric it will cool down the leaner the A/F becomes, as long as your add suitable vacuum advance. On the lean side of stoichiometric the exhaust gas has unburned Oxygen in it and the overlap reversion improves the burn of succeeding firing cycles, instead of quench it like it does with rich exhaust which is high in CO (like it is now).

Contacted Innovate ... unhooked tach signal and O2 values no longer drop our or freeze. Sucks that I cannot use this for data recording! Also sucks that Radio Shack is gone and cannot get a 0-1000 ohm potentiometer by just running across town! ( I am powered from the battery so problem is a dirty tach signal )

[cjperformance]

Certainly looks like you are trying a LOT if stuff to nail this down.
Surely just to satisfy your curiosity and title of the thread you must have thought about just changing the cam/lifters? Im sure you have spent way longer in both time and money on this than a cam swap would take/cost to do.

[topradman]

Certainly looks like you are trying a LOT if stuff to nail this down.
Surely just to satisfy your curiosity and title of the thread you must have thought about just changing the cam/lifters? Im sure you have spent way longer in both time and money on this than a cam swap would take/cost to do.

You are absolutely right on the time & money, however, I have a unique situation in that I have built a cooling system for this customer that should work and again, no room for more radiator without cutting up the car.

If indeed it is the low CR + poor cam selection + shitty header design exacerbating the cam/CR problem, I need to be able to prove it so I am having to take this to the wall! If I change cam & lifters and still have an overheating problem I am in deep shit! If we trade out the motor and it still runs hot, again, in deep shit! ( deep shit meaning I will be buying all this stuff and still end up cutting up the car for more radiator). Because of the changes I have made thus far, I feel like the cooling system is as good as it can get with the current components, strategy and limited space. I have proved this ( at least to myself ) with the fact that an external known radiator for a 454 does not keep it cool either ( see previous post w/picture of radiator in front of car) at sustained rpms of the highway cruising type.

If it was my car, number one, it would not have this mismatched Cam/Header/CR combo. Number 2, if I had bought it this way and wanted to fix it on the cheap, I would have changed the cam out already.

Situation in a nutshell ... customer just purchased the car for a lot of money
customer is a good dude and owns a number of very pissed of streetrods ( this being one of the mildest )
customer did not test drive the car more than around the block at purchase because of circumstances beyond his control
....... ( long story )
car has maybe 500 miles on all of it so hard to sell that the engine is screwed up but he has been pretty understanding
... overall
customer likes the rumpty rump of the cam that's in it and a swap to one that might fix the problem will more than likely
.... not sound at all like it does now
If I can solve the problem with some superficial changes ( am going to work on AFR now, waiting on jets & power valve)
.... I will be a hero and not a zero!!
It's kind of a "reputation" combined with a major amount of "give a damn" on my part I guess. Not a very good business strategy as I will have more money ( via new LM2 + digital temp probes for 8 locations simultaneously + new 5 gas analyzer + time ) than he will in the fix if I can pull it off for him but I guess education costs money. I wasted more on 3 1/2 years of college ( pre-dental, ran out of money to finish ) than this I guess.

What to do????????

[topradman]

Also while im thinking of it, does this vehicle have an X, Y or H pipe in the exhaust? I have had a few badly made setups over the years that have a pipe protruding in too far and blocking half or more of the exhaust flow to all or just one side of the system.

Craig, I am testing now with open exhaust and car does not have x, y or h. I know exactly what your are talking about as we are also a full service exhaust shop in addition to radiator shop.

[topradman]

A word of warning re raising the back of the hood: depending on windshield angle and hood contours, it's very possible, probable even, that the region (especially near the center) is in a high pressure zone* and opening up a gap will further pressurize the engine compartment and reduce radiator airflow. *Think about cowl induction.

I have tested a number of cars with bits of yarn taped at the gap and have almost always found them to be drawn into the underhood area. It's a very simple verification test once the hood is propped up.

Thanks for chimin" in Bill! I think if customer decides to vent the hood it will be with something along the lines of over exaggerated ports on the side like an old Buick Roadmaster. ( always appreciate and respect your input, thank you!)

[topradman]

Without going back and re-reading the entire thread, I've lost knowledge of WHAT the actual engine temps are. The problem mentioned is boiling fuel in the carb making me think the biggest problem is UNDER HOOD TEMPS.

NOT generally favoring holes in a hood, I don't care much for Louvers. There, I said it. HOWEVER, in those rare cases of small frontal area as in the early Ford's, Stude's, and Willy's, it may be necessary to Louver the hood to provide sufficient air flow through the ENTIRE AREA of the engine bay to provide sufficient cooling.

This has been proved time and again on the Flats. You may be experiencing something like this on the street with this combination.

PROVE IT BEFORE CUTTING THE HOOD. Somehow, manage to lift and prop the hood, even an inch. Use a couple of sticks and half a roll of duct tape, something. And run it, see if it makes a difference.

I certainly hope this works!

Some air movement would definitely help this thing out however, when in the shop, it behaves the same way with a 5" air tube on the carb getting air from 5 ft away from the car! But I get where you're coming from.

[topradman]

Ultimately, I will have to get the AFR's right before I can proceed with anything as the car seems to run "good" but exhaust samplings with LM2 as well as 5 gas show it is very rich, especially off idle then it gets more rich as rpm is gradually increase from 20 mph all the way through 65 mph. Full throttle applied at 65 mph dips clear down to 10point something!

[cjperformance]

And good on you for sticking with it till it's right.
By all means have another dig at the jets.
If no luck and you are as sure as can be about the cam then personally, i would (and have done this on a few occasions ) tell the customer your thoughts. Tell him you'll do a cam swap and if it does not work you will change it back all free of charge , BUT if it solves the problem then he pays for all the work and parts.
Sure you risk that work for nicks BUT its one thing proven either way and if it does work you can stop guessing AND the customer will respect you for your call on it.

[topradman]

And good on you for sticking with it till it's right.
By all means have another dig at the jets.
If no luck and you are as sure as can be about the cam then personally, i would (and have done this on a few occasions ) tell the customer your thoughts. Tell him you'll do a cam swap and if it does not work you will change it back all free of charge , BUT if it solves the problem then he pays for all the work and parts.
Sure you risk that work for nicks BUT its one thing proven either way and if it does work you can stop guessing AND the customer will respect you for your call on it.

Thanks Craig. I have been in contact with the owner. As soon as I get the AFR's right, that is exactly what I am going to do. Just sucks because the "nicks" are pretty out of hand already but I signed up for this gig so is what it is. If it doesn't fix, in for cam, lifters, intake gaskets, pan gasket, timing gasket, 8 qts oil change, all times 2 (save cam/lifters) if I have to take it back out, so that is why I want to get the jetting right and see if it will let me tame the timing back down to reasonable levels 1st and still get some cooling. AFR will need fixed regardless.

Most everything I have actually changed has helped. When we started addressing this a couple of months back ( cooling system was originally done last year then cam back this late August for more attention ) you could let it idle all day long w/ac on and it wouldn't overheat, but if you left for a drive after warm up, about 10 miles and we were seeing engine temps rise to 220-230+ and fuel boiling in the carb. After changing to different head gasket design, belt driven water pump, upsizing water necks to all be 1 3/4", etc... I can drive it about 60 miles before temps start getting up to the low 200 area so much better but feel like upgrades are masking what it really wrong ( cam/CR/header design ). If I slow down, it calms down. Same in shop, less rpm, less heat.

Dug a big hole I did!

[Tuner]

IF my LM2 was worth a damn ( locks up off and on regularly ) I would say light load cruise AFR runs about 11.5-12.5ish @ 60 mph around 2650 rpm. If I slow down to about 50 mph and just cruise, temp comes off a bit and AFR hangs around 12.5-13+. ( I am very disgusted with this brand new Innovate LM2 as much as the car itself! )

Thoughts????
Top

Don't throw your LM2 under the bus, I think it might be trying to tell you something about the vehicle's electrical system.

How are you powering the Innovate? If it is a cigarette lighter socket it may be getting an insufficient or erratic electrical supply or ground. Cigarette lighter sockets are notorious for poor ground.

It is also possible a bad plug wire or wires can be causing EM interference. I recently used my LM2 on an engine that has copper wire (old school no resistance at all) plug wires and, no surprise, trying to use the induction clamp to get an RPM signal was an exercise in futility. A sort of usable signal was obtained from the 12V power to the coil + (HEI system) but it was unsteady.

When the induction clamp was on a plug wire or the coil wire, besides the erratic RPM signal, the LM2 would reboot about every minute or two, like the power had been interrupted, tho it had not been. I think it was overwhelmed by stray EMF from the solid wires.

I solved the power supply problem years ago by making an extension cord with a cigarette lighter socket and big alligator clamps from a discarded battery charger so the power supply is connected direct to the battery terminals.

Your electric fan that has a 60 Amp surge to start and possibly some other components in the electrical system could be causing a momentary low voltage condition which will make the Innovate re-start, similar to what using a starter motor does sometimes when the LM2 is already on.

Obviously, the cruise A/F is way too rich. Take a ton of jet out, use larger idle air bleeds, etc. If this engine will run on the lean side of stoichiometric it will cool down the leaner the A/F becomes, as long as your add suitable vacuum advance. On the lean side of stoichiometric the exhaust gas has unburned Oxygen in it and the overlap reversion improves the burn of succeeding firing cycles, instead of quench it like it does with rich exhaust which is high in CO (like it is now).

Contacted Innovate ... unhooked tach signal and O2 values no longer drop our or freeze. Sucks that I cannot use this for data recording! Also sucks that Radio Shack is gone and cannot get a 0-1000 ohm potentiometer by just running across town! ( I am powered from the battery so problem is a dirty tach signal )

How are you getting the RPM signal input, through the 14 wire analog input bundle on the RPM + (Black/White) RPM – (Blue) or using the inductive clamp and the 2 wire connector?