The Top DSM Community on the Web

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. Log in to remove most ads.

Please Support ExtremePSI
Please Support STM Tuned

1G Lifting head?? Maybe... I need some diagnosis & help

This site may earn a commission from merchant
affiliate links, including eBay, Amazon, and others.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Cameron Morison

5+ Year Contributor
51
46
Nov 12, 2018
Christchurch, New_Zealand
Hi Guys

Im in the process of trying to diagnose whether I am lifting the head, or having head sealing issues on my race motor. So in short, here are some main specs
~ 100mm crank
~ 8.5:1 JE pistons
~ Mitsubishi OEM MLS gasket
~ ARP 12mm head studs
~ Galant VR4 block (same as 1G I think)
~ Evo head (same as 2G I think)
~ Borg S200SXE turbo (makes 16psi by 3000rpm in 5th gear!) Running up to 23psi
~ Kelford TX278 Cams
~ 1.1 Bar pressure cap on coolant reservoir

I think that should be enough of the main specs. I'm logging coolant pressure on the Link, using a honeywell pressure transducer. It does have a pressurized expansion tank rather than the factory recovery bottle style. When I have been hitting boost I see a rise in coolant pressure, more pronounced when the engine has been driven hard for more than half a lap, up to 150kpa, which then settles back down to 100kpa as you sustain load, and when you drop off the throttle it goes back down to 80kpa. There is evidence of mainly air getting pushed out the pressure relief of the radiator cap. This happens at all boost levels but the pressure rise in the cooling system was more pronounced at higher boost.

I have just re-torqued the head studs, put them back to the spec 90ft.lbs and some moved a little more, some went back to original position, the ones that moved more were predominantly on the exhaust side. Then I retorqued them again, up to 95 this time, so 5 over the ARP spec. I havnt had a chance to test it in anger (Cant drive it on the road) but on the hoist against the brakes I was able to get it up on boost and the first couple runs the pressure spiked reasonably high, but I wonder if this was due to having topped up the expansion tank to be brimmed. Then the last couple runs the pressure was much more stable at 100kpa throughout the run.

So really, I'm not sure if I have a pinhole leak somewhere or a head lift issue. There are absolutely no other symptoms of head gasket failure, temps are fantastic. Coolant temps are consistent and low 90's. Its not pushing water but that could be part of the design where there is a head of air on top of the water. On the old system where it ran the recovery bottle it would drop about 50mm from the top level in the system constantly, then stabilize at that level.

Attached files: coolant pressure dsm 1 = pulling onto the main straight at Manfeild
You must be logged in to view this image or video.

coolant pressure dsm 2 = on the hoist, loading it up as best as I can in 4th gear, after retorque studs
You must be logged in to view this image or video.


Looking if anyone can share experiences on this topic. where limits were found... solutions etc. Thanks
 
I wouldn't think 23 lbs of boost would lift a head, well it doesn't on my HX40 motor anyway and that is what boost level I am running. Did you have the block and head both decked before assembly?
 
I wouldn't think 23 lbs of boost would lift a head, well it doesn't on my HX40 motor anyway and that is what boost level I am running. Did you have the block and head both decked before assembly?


Neither would have I. In a previous life this block was running around 40psi on a big garret, but the owner at that stage used a o-ring style head gasket. I do want to avoid that if possible so I don't have to skim the head every time it comes off.

The head was skimmed several years before I got it, there were a couple marks on it but nothing that would catch a fingernail. Block had been done in the past so I just cleaned up the surface. Its definitely something I regret not decking both surfaces again but the build was a lot different when I put that motor together and budget was tighter. It would be nice to rule that out but I know that its entirely a possibility.
 
Yes, at least you are aware of that. I understand the budget in different stages of life. My engines all get decked and heads surfaced now. Just something I do to make SURE it is going to seal. I use Cometic MLS and HKS headgaskets on most builds, although I do have a newly rebuilt "stockish" motor that has a FelPro composite on it. On all, I hold the head down tight. More than specified by a book or manual but I don't recommend it unless you have confidence in your abilities to do it.
 
All of the motors I’ve built use L19s with an hks head gasket. I had a similar issue on a motor when using an oem mls headgasket without freshly decking the block. The hks gasket is just a much better gasket imo , I’d recommend switching to an hks and increases the torque to 105-110, if you can afford it go to the l19s for good measure. When I say freshly decked I mean Within a few thousand miles for the record.
 
Have you considered the thought that coolant can pressurize from other sources? Is the turbo water cooled? Do you have coolant going through the throttle body?
 
All of the motors I’ve built use L19s with an hks head gasket. I had a similar issue on a motor when using an oem mls headgasket without freshly decking the block. The hks gasket is just a much better gasket imo , I’d recommend switching to an hks and increases the torque to 105-110, if you can afford it go to the l19s for good measure. When I say freshly decked I mean Within a few thousand miles for the record.

Interesting. Its so hard to know what head gasket is best but I am open to finding another good one. Permanent is a common and easy brand to source here in NZ, i will try to find out about if they are any good also
 
I see HKS advertise theirs as being a stopper style gasket, is OEM one like this too, or does it have a different construction?

The turbo is only oil cooled, throttle body doesnt have water lines.
 
I see HKS advertise theirs as being a stopper style gasket, is OEM one like this too, or does it have a different construction?

The turbo is only oil cooled, throttle body doesnt have water lines.
The hks head gasket has more layers and each layer is thicker.... It’s really the best you can do for this style
 
Ok, good things to consider. Im going to go warm up the car and get it on boost to see if I have any leakage measured. Hopefully nothing like the final runs last time. If I do have leakage then I think Im going to go down the new head gasket route.
 
Ive just finished doing a couple of runs just against the brakes on the hoist. Promising results:
~ first three runs, basically I started once the water temp was up to thermostat temp, the engine hadn't fully heat soaked yet at that stage though. The first run was zero change in coolant pressure, sat at 100kpa (I've just put a 1.3 bar cap on), second run saw a rise to about 160kpa, but it wasn't in line with boost, happened very late in the piece, 3rd run was similar.

You must be logged in to view this image or video.


~ last couple runs were rock solid and only slight and gentle increases which I put down to the rising coolant temperature.

You must be logged in to view this image or video.


So at the moment I think I am going to be best to leave the gasket as-is, go out racing and collect data under race conditions and go from there. Im tossing between the Permaseal MLS-R gasket and the HKS one, both use folded stopper rings, and same 4 layers of steel, a friend has been using a Permaseal one in his Evo which is around 600whp with no issues, but plenty of time to research as its a while before Ill be able to get race data

I will keep the thread updated as it develops.
 
Update to the thread. Had a 1/4 mile sprint today. Not at a strip, just on a closed road with the local car club. I was running 265kpa, so 1.65 bar boost and temp was about 15 celsius. It seems the head gasket issues are gone, the coolant pressures remained normal and followed a curve which related far more closely to coolant temperature than anything else, so thats excellent news. Means I can run the engine at the higher boost levels without having to be concerned about the head.

I got the PB down to 10.34 which is pretty decent. Hoping to get a 9 one day which will need better road surface (it was rough chip) or better tyres designed for doing drags rather than corners.

You must be logged in to view this image or video.


You must be logged in to view this image or video.
 
Last edited:
To raise a dead thread...

I blew the head gasket at an event the other day, well not blown, it lifted the head enough to blow out the water and then it settled back down and resealed, no misfires and holding coolant pressure afterwards. However leading up to the issues I was seeing quite sharp rises in coolant pressure up to around 140kpa. Because we were so focused on re-tuning the closed loop boost control during the event and minimal time between runs the coolant pressure didn't get noticed unfortunately.

it seems as though the issue has been erosion of the head stud clamp area in the head. Its got a bit of an indentation and some evidence of fretting. I think this has been the issue the whole time now looking at it, and a bit of a search online suggest that it is a bit of a design issue on the 4g63 and there are several companies with fixes.

So I've got the head off now, getting reskimmed (hardness tested ok to use, and was perfectly flat), and the stud clamp surface is being refinished and machined to fit a 'hat-washer' which prevents the washer moving around against the head. A bit like the TMZ one but is a locally produced product.

Hope to have the car back together in a few weeks once parts arrive. will be using the stopper ring style Permaseal MLSR gasket this time, its a nice looking unit!
 
I don't, or haven't yet, done the time serts but I would do just about the same as @ist dwa.
I have my own head torque specs and I guarentee if you lift a head, it is more than 50lbs of boost. On my personal engines with the L19's, I run 115 ft/lbs on the studs (special washers to spread the load better and creeping up on my values). I can get flamed for it but this isn't my 1st rodeo and when I do my own motors to my specs, they hang in there even tho I abuse the heck out of them (9200+ rpm's).
It's not a HP motor, but my Saturn 1.9 DOHC daily driver motor is similar to 4g's and I just turned over 60,000 miles on it this week after a rebuild 3 years ago. I don't expect to get that out of a HP 4g63 build but they hold together with a lot of little tricks and attention to details. My current 4g63 is at least 500hp, my buddies and kids think more but we don't have access to a dyno and really don't care about numbers, just the fact my little ragity looking TSI will out run anything I can find on the road and I even challenge bikes, just to see how good my shit runs! Lol, that last phrase sure came out bad, anyway let us help you help yourself! :)
Marty
 
115 is too much.

PER ARP

"The recommended torque spec is given to ensure the stud does not yield out and remains reusable. Having said that, you can increase the torque spec 5-10ft-lbs but you will be very close to the yield point.

Thanks,
Martin Ramos
ARP Special Orders
[email protected]

Best regards,
Martin Ramos

Technical Support
Automotive Racing Products, Inc.
800-826-3045
ARP-bolts.com"
 
Thanks. That is the reason I put the disclaimer on my reply. I will continue to build MY engines the way I have for 40 years. I do not suggest anyone else do it, they are only MY specs.
Customer motors get different values.
If you dont push the limit, you won't know it.:)
Marty
 
instead of all these crazy recommendation for head studs and gaskets, yall should be looking for why he is having trouble with headgaskets at 23psi. Either it's not got a good enough deck surface, or it is rattling. Better gaskets/studs won't fix either of those. Just be harder on everything else. Fix the problem, not the symptom.
To raise a dead thread...
!
We need more info to really help you. Where is your coolant pressure sensor located? What does your tune look like, what fuel, ect. 23psi is in the realm stock stuff should be lasting without issue. Being that this is some sort of a lapping car you shouldn't have it so cranked up it's on the verge of leaking anyway.

My current setup makes a significant amount more power than what you are doing. I'm using a 9627pt and 25yr old 8740 arp studs at 105. Headgaskets are the least of my worries. it's in the neighborhood of 800hp and it's only on 30psi - so the tune up isn't soft by no means - everything is happy. it's not a lapping car, but some days it might see 15-20 1/8mi passes in a couple hours time - so close enough.
 
I also torque the head to 110-120lbs depending on how I feel. You are likely a bit hot in the timing department or are increasing your cylinder pressure in some other way. More info is needed.


My experience is that the words “Lifting the head” are used way too often. Unless you are making 6hp/cubic inch or more, you aren’t making enough cylinder pressure to shove the head off the block.

I am able to keep a head gasket in a 4g63 very consistently to 1000whp. And with land speed racing I certainly take things to the extreme as far as service and duty cycles. It is just like told someone last week. Your head gasket didn’t fail you, your tuner did.
 
Last edited:
Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Innovation Products Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com RixRacing RockAuto RTM Racing STM Tuned

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds

Back
Top