Any alternative markings to do cam gear timing with???

cuel

Supramania Contributor
Jan 8, 2007
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Timing covers are like insurance, kind of. They might not be 100% necessary, but you'd definitely wish you had them if something fell in there(like that harness laying just behind the cam gears ;)). Knowing exactly where the timing marks are for the cams is good, to.

The thermostat controls coolant flow, and thus temperature. It opens at a particular temperature(195 stock, iirc), to let the hot coolant flow out of the motor, and be cooled by the radiator, and lets cooled coolant flow from the radiator to the motor. It also closes at a particular temperature(not sure where that is), to hold coolant in the motor to properly absorb heat before flowing back through the radiator. Sounds like yours is stuck.
Timing can effect temps, but you'd notice other symptoms as well, as it would have to be a good bit off. Slight stumble if you blip the throttle is a good indicator of being a tooth off.

Edit: Damn, beat by both!
 

IwantMKIII

WVU MAEngineering
Jun 12, 2007
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Perkasie, PA
jdub said:
Hmmm...coolant thermostat?

TSRM Thermostat

The way your temps drop at speed is leading me to believe either you don't have one installed or it's stuck open.


IDK, that's for another day i guess. Likei said though, temps are typically right around the 180 mark around town or heavy/constant throttle. maybe hits 200 under a lot of boost then simply cools to 160-180 depending on temps outside

Edit: can this negatively affect performance?

cuel said:
Timing covers are like insurance, kind of. They might not be 100% necessary, but you'd definitely wish you had them if something fell in there(like that harness laying just behind the cam gears ;)). Knowing exactly where the timing marks are for the cams is good, to.

The thermostat controls coolant flow, and thus temperature. It opens at a particular temperature(195 stock, iirc), to let the hot coolant flow out of the motor, and be cooled by the radiator, and lets cooled coolant flow from the radiator to the motor. It also closes at a particular temperature(not sure where that is), to hold coolant in the motor to properly absorb heat before flowing back through the radiator. Sounds like yours is stuck.
Timing can effect temps, but you'd notice other symptoms as well, as it would have to be a good bit off. Slight stumble if you blip the throttle is a good indicator of being a tooth off. Edit: Damn, beat by both!

I have that, ill hit the throttle and there is almost a slight delay drops barely in RPMS and then raises strong. Typically that hesitation is only while at idle. anywhere else in the RPM range it seems to be fine from what i notice. The engine always did this though, even since the rebuild.....i wont know if its off till i get the cover. All i know is there are 18 notches from BEFORE the exhaust mark to just Before the intake mark. With my aftermarket gears the lines are not exactly in the middle of the tooth.
 

jdub

Official SM Expert: Motor Oil, Lubricants & Fil
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IwantMKIII said:
IDK, that's for another day i guess. Likei said though, temps are typically right around the 180 mark around town or heavy/constant throttle. maybe hits 200 under a lot of boost then simply cools to 160-180 depending on temps outside

Edit: can this negatively affect performance?


Short answer...yes ;)

Like I said, below 176 deg F the ECU will go to warm-up enrichment...you will run rich. Above 210 deg F, the ECU retards timing in an effort to prevent detonation.

You are showing big temp swings...that is not what you usually see. OAT will only affect this to the extent the radiator can get rid of the heat...you are not having this problem. The good news is you are not overheating. I would def check your thermostat...you want one rated at 190 deg. I like Stant Superstats..cut the jiggle valve off before you put it in.
 

trydrew

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I like Stant Superstats..cut the jiggle valve off before you put it in.

I'm just curious (not trying to get off topic) but what does the jiggle valve do and why are you recommending to cut it off on the Stant?
 

jdub

Official SM Expert: Motor Oil, Lubricants & Fil
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Feb 10, 2006
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I recommend cutting them off on any thermostat for this car. It's there to allow air to pass and exit out the radiator cap. What I've seen is pressure can build up behind the stat, holding it closed...the coolant lines to the CT26 also acts as a bypass to help prevent this. It usually works good, but at times you'll get a random coolant temp spike in the 1st 10 minutes of driving. Using a oil cooled only turbo makes this much more common if you remove/block the coolant lines.

Cutting the jiggle valve off allows a small amount of coolant to always bypass the thermostat...no more pressure build-up. The delay getting to ops temp is very small.
 

Supracentral

Active Member
Mar 30, 2005
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jdub said:
I recommend cutting them off on any thermostat for this car. It's there to allow air to pass and exit out the radiator cap. What I've seen is pressure can build up behind the stat, holding it closed...the coolant lines to the CT26 also acts as a bypass to help prevent this. It usually works good, but at times you'll get a random coolant temp spike in the 1st 10 minutes of driving. Using a oil cooled only turbo makes this much more common if you remove/block the coolant lines.

Cutting the jiggle valve off allows a small amount of coolant to always bypass the thermostat...no more pressure build-up. The delay getting to ops temp is very small.

My MKIII has two 1/32" holes drilled on either side of the jiggle valve hole (which is also removed). I originally did it because I had an air bubble that I could NOT get rid of no matter what I did. It's added a few minutes to warm up time now that it's cool out, but its not bad.

I had intended it as a temp fix, but my oil temps are dead on, so I never bothered to remove it.
 

cuel

Supramania Contributor
Jan 8, 2007
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Baytown, Texas
IwantMKIII said:
I have that, ill hit the throttle and there is almost a slight delay drops barely in RPMS and then raises strong. Typically that hesitation is only while at idle. anywhere else in the RPM range it seems to be fine from what i notice. The engine always did this though, even since the rebuild.....i wont know if its off till i get the cover. All i know is there are 18 notches from BEFORE the exhaust mark to just Before the intake mark. With my aftermarket gears the lines are not exactly in the middle of the tooth.

Did you have your head and block milled? The stumble is a good sign of the timing belt being out of time one way or another. When you get the cover, set the crank mark where it goes on the bottom cover, with the cams pointed up where you set them, before removing the belt and cam gears. Once you get the plate on and belt installed correctly, see if the stumble is still there. It is possible that enough material has been removed from the head and block to change the distance enough between the cams and crank to effect timing. You should be able to turn the cams back(clockwise?) a degree or 2, with the adjustable gears, to make up the difference. I hope I got that right...
 

IwantMKIII

WVU MAEngineering
Jun 12, 2007
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cuel said:
Did you have your head and block milled? The stumble is a good sign of the timing belt being out of time one way or another. When you get the cover, set the crank mark where it goes on the bottom cover, with the cams pointed up where you set them, before removing the belt and cam gears. Once you get the plate on and belt installed correctly, see if the stumble is still there. It is possible that enough material has been removed from the head and block to change the distance enough between the cams and crank to effect timing. You should be able to turn the cams back(clockwise?) a degree or 2, with the adjustable gears, to make up the difference. I hope I got that right...

I have exact measurements of what was taken off and where, just not here. they are all at school. ill get back to you on that also when the cam cover comes, which again, THANKS FORCEDTORQUE