Roush Engine Experts.

[jhv48]

Ok, here's the scenario:

Just bought SPF 2932 (new) and the oil and water temps got real high today. Both close to 120 degrees celsius. Air temp is about 90 degrees oustside. Traffic was stop and go. Has run warm since new, but not this warm.

Assuming all other parts are correctly installed and the correct type, I went to check the timing. I have a 427 SRTW with the MSD mechanical advance distributor. I went to put the timing light on it and the light showed over 20degrees on the wheel at idle. But, there is a blue timing mark that someone has put on the wheel that is at about 2 degrees BTDC. So, how do I set the timing on this thing? The specs say 31-34 degrees at 4000 rpm. So, what do I set the idle timing at? Or should I run it up to 4000 and set the timing at 32 degrees? And what is the blue line for?

Someone tell me the proper way to time this thing. I have a feeling it is slightly on the too advanced side.

[poisonsnake]

Jim - I also had similar issue w/oil temp.on brand new #2899. I was told many cars don't use oil cooler. Guess what-I did and made all the difference. Don't forget soft bends. Good Luck!!! MT

[jhv48]

Originally Posted by poisonsnake

Jim - I also had similar issue w/oil temp.on brand new #2899. I was told many cars don't use oil cooler. Guess what-I did and made all the difference. Don't forget soft bends. Good Luck!!! MT

I've got the oil cooler hooked up. Still got plenty hot today.

[ekrupa2]

Jim - I have the 402 SRTW. Timing set at about 12 at Idle...30 at 4000 RPM. When hot run anywhere between 80 and 100 C tops. Have you pulled the sensor bulbs and tested their accuracy (usually with a known water temperature)? Another way to check is with an infared temp gun on various parts of the engine. If you can eliminate the gauges being off then you can start to diagnose the engine itself.

[Chilibit]

You don't refer to the fans coming on, usually at 100C. It continues to climb with the fans on?

[ekrupa2]

Originally Posted by Chilibit

You don't refer to the fans coming on, usually at 100C. It continues to climb with the fans on?

Excellent point...assumed the fans were coming on but exactly as Chilibit mentions if the fans dont come on in stop and go traffic, you will have overheating issues before you know it.

[olddog]

Originally Posted by jhv48

I have a 427 SRTW with the MSD mechanical advance distributor. I went to put the timing light on it and the light showed over 20degrees on the wheel at idle. But, there is a blue timing mark that someone has put on the wheel that is at about 2 degrees BTDC. So, how do I set the timing on this thing? The specs say 31-34 degrees at 4000 rpm. So, what do I set the idle timing at? Or should I run it up to 4000 and set the timing at 32 degrees? And what is the blue line for?

If this is a mechanical only - no vacuum advance - distributor, I would say set it at the high rpm. The spec seems odd to me. I would think the mechanical should be all in by 3500 rpm at the highest. I would get some help and map out what it is doing. See where the timing is at 1000, 1500, 2000,,,,,,, until it quits advancing.

If it has vacuum advance, you should disconnect and plug the vacuum line. Then see where it is at, when at an idle. This should be at 10 -16 depending on the cam.

For a street driven car, personally I feel it should have a vacuum advance. To me mechanical only is for race only applications, where you only care about WOT operation.

As for the blue line, it could have been put there for many reasons. It is possible that someone found that that is the true piston TDC and marked it rather than move the pointer to correct the problem.

[jhv48]

Fans were on the entire time I was stuck in traffic. I switched them on and left them on.

I reset the timing to 15 degrees and will check it out this afternoon when the temps are hot again.

[Chilibit]

At idle or thereabouts there is no huge advance dialed in.

It would be interesting to see if the fans come on at 100c on the dash board. I think that there is no linkage between the fan sensor and the dash gauge. If they come on at 100 or pretty close then the dash readouts are probably pretty close.

Does it run this hot at night when the ambient is way down?

[madmaxx]

the answer to your question.

1) set base timing to about 18 to 20 degrees at idle
2) Now rev the engine in neutral and see what the timing is. you may want to mark your harmonic balancer at 32 degrees so it is easy to see. Yes it will be loud, at 4000 rpm all timing should be in so if you rev over dont worry the timing will not advance anymore. The advance is controlled by springs underneath your rotor in your distributor.

If you have an adjustable light you set the advance at 32 degrees then rev to 4plusk and you should be on zero on your harmonic balancer. It is critical you rev the engine and dont use a spring curve to calculate advance.

[Roush #1]

Jim,

Your total (initial timing plus advance in the distributor) timing should not be over 34 degrees.

All of your timing should be advanced by 3,500 RPM if yours is like most Roush MSD distributors. If you check it at 4,000 is shouldn't be any higher than it is at 3,500 ........if it is like most Roush distributors.

Check it at 3 or 4 thousand (wherever all the advance is in) and set it somewhere between 31 and 34 degrees. Try it out and see which one you like best just don't get much over 34 degrees total.

Mine (427 SR/TW #444) likes 34 degrees total, but there is not much difference between 31 and 34. My timing at idle is about 12 degrees.

BTW...some timing lights do not like MSD products and will not work properly with them. If you can borrow another timing light it wouldn't hurt to check the accuracy of yours.

Hope this helps.

Jody

[madmaxx]

shoot the $10.00 timing light I bought from harbor freight worked great, sure you had to use it at dusk since it was not that bright but what the heck, LOL!!!! And when i melted the pick up on the header it did not hurt so much!!!

[jhv48]

New wrinkle.

Today I went for a 15 mile drive and the temp spiked to about 120 on the freeway with the fan running. Limped home (temp never got below 115) and pulled into the garage just as the overflow tube puked about a gallon of coolant. With the engine off, I could hear the coolant boiling and the gauge went to about 250. No problem cleaning up the coolant. Dog licked it all up when it cooled down. Now I need a new dog too! (just joking).

Now what? I have a hunch that this isn't a timing issue. I'm loading it onto a flatbed and having it checked out at Danmar Autobody in Costa Mesa. They did the install and hopefully they can shed some light on the problem.

It has always run on the warm side, but today it boiled. Could there still be an air pocket that wasn't burped out? Or am I looking at a gasket problem. Oil is clean and there is no coolant coming out of the pipes.

[mln385]

Drill 2-3 (1/4") bypass holes in the t-stat for coolant flow.
I did this (only put 1 as I live in New England )and it has helped, it was suggested I put 2 in but I drive mine in early spring and fall so to many holes would not allow it to come up to temps. in those months.

All in all I beleive these motors put out to much heat for the stock radiators in traffic, just my opinion though.

Marc

[Goopie 18]

Are your fans running the proper way? They pull the air. Maybe your wires are crossed and your fans are pushing.

[G_Edmonds]

jhv48
Don't overlook the simple things too. Your last drive sounds just like what happened to me last week while taking my daughter to college. Turned out to be a bad radiator cap.
-Greg

[jhv48]

I hope you're right!

[patrickt]

Jim (elmariachi) knows more about overheating Cobras than anyone on this forum. You can review the thread below, or consult him off-line, but touching base with him will save you a lot of time.

http://clubcobra.com/forums/showthread.php?t=97316

[jhv48]

I read all the threads I could find including his.

My situation is a little different. All items are new SPF. For the past month, the engine temps have fluctuated a lot during normal driving. In town, 75 degrees out, stop and go temps would be 110 oil, 110 water. Get on the freeway, same day and the oil and water temps would back way down to 65-70 degrees.

The last two days, the oil temp would climb to 110 in about ten miles and the water to 120. Fan on, freeway driving had no effect on the water temp, but oil would back down to 105. Pulled into driveway and shut it off with the fan running and the temp spiked immediately and it puked all over the floor. Could hear the boiling coolant in the tank. Hoses were hot, radiator was hot, engine was hot. No sign of oil in coolant and no sign of coolant coming out of exhaust pipes.

Just took it back to the installer for diagnosis. Will let you know what he finds.

Would an intake manifold gasket leak cause these symptoms? How about if they forgot to install a thermostat? Leaking head gasket?

[patrickt]

Usually when you see "monster variations" you think air-bubble. Replacing the thermostat with one you've tested on the stove and burping the system (when you can't spot something obvious) is usually the first step.