heat cycling and retourqing arp head studs

[byron]

i am just about to finish up my car here and one thing i am unsure about is retourqing the head studs? what exactly is a heat cycle?

[e36'n]

Not really sure as I haven't done a HG.

Updates???

[JamesM3M5]

Heat the engine up to temp (at least 10 mins of running) by driving easy. Make sure you don't overheat the engine, and bleed the coolant before taking it out on a drive. Then let the engine cool overnight so it's stone cold, remove the coils and valve cover, and do a final torque. I just did a Cometic w/ ARP studs (for the second time now) on a twin-screw, and I set the final 4th torque stage (after heat cycle) to 70lb-ft. The first Cometic blew out at 60lb-ft and several track events. The owner is a HPDE instructor, and runs many schools each season. He'll be at RA this coming weekend.

[CosmoE36]

Byron.... yo dont have to retorque ARP bolts.

just Torque to 70 ft lbs and dont look back. thats what i did.

as far as the heat cycling goes, i heatcycled my motor with NO COOLANT so that the Copper Seal i sprayed onthe headgasket woudl get nice and dry.

i put motor back together did NOT put any belts back on and did NOT fil with coolant.

i started the motor and let it get to sightly under TEMP, only because theres no coolant going through the thermostat so its hotter than what it says it is.

let the motor cool down and then put belts back on coolant back in. havent had any issues 300 miles so far and i have been hitting 10 psi

[byron]

hmmn, conflicting info:help lol

[bmwperson]

ok i have tried this at least on 3 different cars, no retq per Tonys(VAC) advice.

do a 20/20/40/40/65/65ft-lbs with 15m in between, I actually went ahead and checked the tq after a few heat cycles... they didnt move a touch...

[RRdawho?]

this is somewhat OT but did u refinish the head?

[Bassmaster]

ARP do not need to be retorque.
My torquing is 15,30,40,50,60,70.

[slvr98 M]

I retorqued after several hundred miles. Some of the bolts had about 1/4 turn on them. Even at 70lbs it was needed. VAC and a few others recommended it to me.

[e36'n]

ok i have tried this at least on 3 different cars, no retq per Tonys(VAC) advice.



I retorqued after several hundred miles. Some of the bolts had about 1/4 turn on them. Even at 70lbs it was needed. VAC and a few others recommended it to me.
:confused


Byron did the shop get the IC and exhaust pipes done yet? When do they start tuning?

[kalib0y]

when you retorque does it just require you to just torque them down to 70ft lbs after heat cycling or do you have to back the studs out, reoil the thread with 10-30 and then torque to 70ft lbs?

[JamesM3M5]

I guess what I did, per others suggestions, was not a "retorque", it was a final 4th torque stage. The previous gasket job I followed Tony Salloum's advice and did multiple repeats of the 3 main torque stages (20, 40, 60) since the compressing gasket caused the first studs to be loose by the time the later studs were torqued. Bottom line is the head gasket lasted less than a year, with obvious signs that the gasket sealing material was compromised at the #6 coolant passage seals.

So this time, after scouring the Intarweb (BF is invaluable for this type of info), I followed a club-racer's suggestion to do the 20/40/60 torques, heat up, cool down, then do a final 4th stage of 70-75lb-ft without loosening any studs. I found that some of the outer studs (toward the front and back of the engine) needed more angle to set to 70 lb-ft, while the ones in the middle required very little motion to get up there. They all turned, nonetheless, so I know the lube was still good on the studs/nuts/washers.

I am not sure that heating up an engine without coolant is such a good idea. The ports in the head are rather thin, and aluminum, and they need some medium to transfer heat from the 700-1000F exhaust gas. Whenever I run an engine without coolant, it's usually only far enough to move the car.

[slvr98 M]

I guess what I did, per others suggestions, was not a "retorque", it was a final 4th torque stage. The previous gasket job I followed Tony Salloum's advice and did multiple repeats of the 3 main torque stages (20, 40, 60) since the compressing gasket caused the first studs to be loose by the time the later studs were torqued. Bottom line is the head gasket lasted less than a year, with obvious signs that the gasket sealing material was compromised at the #6 coolant passage seals.

So this time, after scouring the Intarweb (BF is invaluable for this type of info), I followed a club-racer's suggestion to do the 20/40/60 torques, heat up, cool down, then do a final 4th stage of 70-75lb-ft without loosening any studs. I found that some of the outer studs (toward the front and back of the engine) needed more angle to set to 70 lb-ft, while the ones in the middle required very little motion to get up there. They all turned, nonetheless, so I know the lube was still good on the studs/nuts/washers.

I am not sure that heating up an engine without coolant is such a good idea. The ports in the head are rather thin, and aluminum, and they need some medium to transfer heat from the 700-1000F exhaust gas. Whenever I run an engine without coolant, it's usually only far enough to move the car.


Thank you.

I dont see why it wouldnt hurt to retorque at 70 lbs. anyway. What are you losing, about an hour of your time? All of the companies I deal with that build high boost applications recommend it.

There are also conflicting reports of using or not using a gasket sealer on the MLS as well. Even the people that sell them recommend it.