MeanMini 's cooling system anomaly: coolant push to overflow

[wheming]

Normally, all the pressure in the cooling system comes from the expansion of the coolant due to heat. Having said that, what I would do is warm up the car completely with the system open so that no pressure builds up in the system. Then, put a cooling system pressure tester on the car, using it only as a gauge, and then go do a full boost run down the road with it hooked up and see if the pressure in the system rose substantially when you come back. If so, that pressure would be coming from a combustion leak into the cooling system.

You can also do a 'block test', but I am not sure how recently the gases have to have leaked into the cooling system for the fluid in the tester to change color.

However, with a cooling system pressure tester in place, there would be no relieving of the pressure at any point though. Is that correct? So if what we think is happening happens, the combustion pressure will spike cooling system pressure, and we couldn't regulate what the pressure limit is?

[thedon809]

Yeah you just want to do a quick pull to see if the pressure jumps. A block tester uses a liquid that changes color when combustion gasses hit it.

[mopar-tech]

Do you mean the same as a leakdown tester? I almost tried that today.

I would warm the vehicle up and use the leak down tester to pressurize each cylinder on TDC and see if there is any change in the coolant level in the radiator.

If you pressurize a hole and the coolant starts moving around then you know you have a crack in a chamber or a leaking headgasket.

[Gaboon]

I've had the same issue in the past. The head lifts at high boost pressures and in turn pressurized the coolant system. No biggie.

Crank those studs up to 100ft lbs if not a little more.

[csxtra]

I heard something today, and would want to verify if there are two different ARP stud kits for our application. Did James Reeves have a similar issue and found he had the wrong headstuds? I'll need to check that out.

That is correct. On the older ARP head stud kits, the shank (non-threaded) of the stud necked down to a smaller diameter than the threaded portion. Supposedly the newer kits don't neck down.

A couple of years ago, James was talking to Warren Stramer and he had noticed the necking down and called ARP looking for a compatible 8 valve stud that didn't neck down. He got a part number and ordered a set of individual studs and Reeves did also. They verified that on these studs, the shank was the same diameter as the threaded portion.

I waited a few months and when I tried to order the individual studs, I was told by ARP that those are the same studs that are in the kit. I was on a short timeframe to get the car ready for SDAC and didn't want to take the chance of getting the weaker studs, so I custom ordered the studs individually (at a SIGNIFICANTLY higher cost) and they were indeed the thicker ones.

I have not verified that the latest kits contain the thicker studs, perhaps someone has a set that hasn't been installed yet and can verify.

Here is a picture of a necked-down head stud (notice it looks like a Q-tip):



Unfortunately I don't have a pic of the thicker studs for comparison.

Without pulling a stud out, I'm not sure how you can tell whether you have the thicker ones or a Q-tip, maybe someone else knows. The only markings on the Q-tip studs are the two "ARP" stampings on the head next to the hex.

I hope this helps.

Warren

[wheming]

The stampings visible on mine are ARP 2000
And i cannot remember if i looked closely at them when i received them. They were just all boxed up with all the other parts for Mini's build.
I will see if i can track the part number i ordered down, to see if that reveals anything.

[wheming]

from ARP's website, says kit 241-4501 is undercut
http://arp-bolts.com/kits/ARPkit-det...?RecordID=1587
I need to verify with the vendor this is the kit I received though.

Does anyone know what application or part number for the full diameter stud?
I might need to call ARP.

Also, their instructions say to torque to 90 ft-lbs. So, I guess at the very least I should try going up to that torque spec.
http://arpinstructions.com/instructions/241-4501.pdf

[thedon809]

Another thing to do is what Chrysler does with the new 3.6l. You torque the head down, loosen it back up, and retorque the head again.

[wheming]

son of a biscuit!
I had a reply all crafted and then lost it! Sometimes I hate computers!

anyway, I called ARP and talked to a tech support guy. I asked him about the 241-4501 kit which says undercut on the website. He said it was not, and that the website info was wrong. He said the kit was ARP-2000, which apparently is the higher grade/strength material. (I can see that indicated on the ends of my studs, so that is good news.) Further, he said ARP does not have an undercut stud kit for our application anymore. It might be that customer feedback from the likes of the members here got them to stop offering that kit if they were getting contacted with problems.

I called the vendor, and he is going to check to verify the kits are in fact full diameter studs. So I should have that info later today.

[wheming]

Ok, so here's my immediate path forward...
Trying to locate some ARP assembly fastener lubricant to retorque the headstuds, and will probably go to 95 ft-lbs to start with. ARP recommends 90, but with these studs being the ARP 2000, there should be little concern in torquing a bit higher.
So with the engine cold, i'll back them off one at a time, relubricate all the required surfaces, and then torque them down to 45 ft-lbs until they are all reassembled with new lubricant.
Then i will step torque up to 95 ft-lbs.

I don't like the thought of removing all the nuts at one time.

[mopar-tech]

Any moly based lube should be fine, I'd do minimum of 100 ft/lbs myself.

[wheming]

Any moly based lube should be fine, I'd do minimum of 100 ft/lbs myself.

100 ft-lbs, even using a Cometic MLS headgasket?
Does that make any difference?

I did find some ARP Ultra Torque fastener lube not too far away at a speed shop. I'm going to get it right now.
Since they are so picky about it in their instructions, i may as well use their stuff since I can get it.

[thedon809]

If anything the MLS gaskets can withstand more torque because they don't squish like the oldschool graphite or composite gaskets.

[wheming]

I've been at a stand-still the last few days. Had to to some yard work before the rain and an impromptu picnic with the wife then Halloween with friends used up my only opportunity to work on Mini. I really hate not having a useable garage for car work. And now we have 3 days of rain in store and i go back to work.
Hopefully Monday i can get all the head stud fasteners re-lubed and re-torqued. I hope the heck that does the trick.
The pressurized coolant expansion tank i ordered turned out to be ginormous, so back to the drawing board there. Need to search for one that would work. Ideally it would use a regular radiator cap, and have an outlet to go to an overflow.

Might try to use one from a jetta. That ball shaped one might work, if i can get a 16psi cap instead of the 22.
At least with the expansion tank, i wouldn't loose coolant hopefully, the air/gases could be purged out when the pressure rises.

[GLHNSLHT2]

Wayne, here I thought you were following my build thread



89 volvo 760. Pressurized, has the pisser knozzle to get air out, and a 3/4" return on the bottom. Great mounting bracket if you can get one out of a j-yard car. I haven't seen the bracket for sale on Ebay though maybe. I sanded off the top of the cap to remove the volvo on mine but I recall it being close to 15-16psi written on it.

[wheming]

Wayne, here I thought you were following my build thread

89 volvo 760. Pressurized, has the pisser knozzle to get air out, and a 3/4" return on the bottom. Great mounting bracket if you can get one out of a j-yard car. I haven't seen the bracket for sale on Ebay though maybe. I sanded off the top of the cap to remove the volvo on mine but I recall it being close to 15-16psi written on it.

Wait a minute, i am following it! Didn't i say i have to remember that?

I had to look back but see you are using yours for your IC setup.

[wheming]

Looks like the cap vents to atmosphere.
I can't find a great pic from the top. But this shows the shape.
http://pages.ebay.com/link/?nav=item...194655&alt=web
The caps look like 1 bar, 150 kpa, so about 15psi.

[GLHNSLHT2]

Wayne I'll try to get some pics of it and the bracket this weekend. The cap does vent to atmosphere, and yes I'm running it for my water/air ic setup. I'd take the spring and valve out of the factory rad cap, run the small nipple off the rad neck to the small nipple on the expansion tank, and then T into the returning heater hose to the water pump from the 3/4" nipple off the bottom of the expansion tank.

[GLHNSLHT2]

Caps on mine are 75kpa or that's what's printed on them.







All cleaned up and ready for install into a Turbo Mopar




And then this style is out of a 240 volvo



Wide and skinny but the bracket would have to be refabricated a bit.

[Dr. Johny Dodge]

the little hose that runs from the filler neck to the overflow jug .. is it the original or an old piece of hose?

if so it might be full of crud that allows the collant to flow to the jug because there's enough pressure to drive it into the jug but if somewhat pluged up it might not allow the coolant to reverse flow when the engine cools down

also if the nipple on the filler neck is lose or has a pin hole the same problem could result

sediment in the overflow jug could also stop the reverse flow of coolant too