Why does an 8psi turbo on stock motor blow a new headgasket, twice?

[Vermont320i]

I had blown the headgasket last fall and put a new one in. Oil test from Blackstone labs when I changed the oil this summer indicated no coolant in oil. Based on that success, I put together and installed a mild turbo setup on my 1981 1.8L. I used a Victor Reinz headgasket and new head bolts, using factory service manual and Haynes manual as guides. Boost gauge installed. Have not yet received the Air fuel mixture gauge so I don’t know those numbers, but I don’t think that is my problem right now.

First time: At initial start up and idling, it seemed to be pressurizing the oil pan and the valve cover—-leaking from oil fill cap and dipstick popped up. (I ran the turbo oil drain to a new fitting on the oil pan—a factor?). When I put a vented the valve cover to atmospher it seemed to solve this issue. After that I took it for its first drive. Engine ran fine, so after 20 miles I ran it on the interstate at a steady 3500 in 5th gear (minimal boost on gauge at steady state) and it started to overheat after a few miles. Shut it down when temp gauge spiked. Radiator (previous owner had a plastic tank radiator installed—-no idea why) had a crack in it and had leaked severely. Coolant in exhaust manifold. Headgasket blown/stretched—-4th cylinder area had a teardrop shape to it. Maybe the fault of a coincidental radiator failure? Or turbo pressurizing?

Pulled head and swapped it with a rebuilt one from CHI ($450 very fast shipping and good customer service, by the way), installed that, again with Victor Reinz gasket, bimmerforum copper gasket spray trick, and new head bolts. Torqued per service manual. Valve clearances checked and set to .007. Installed new radiator from chr racing (very nice as well. $195). Set timing with timing light.

Ran very smoothly and strong, very happy with it driving on 2 lane VT roads, drove like that for about a half hour, not beating on it, never over 4500rpm. Stopped beside road and saw some white smoke from tailpipe. Maybe just burning off some of the previous stuff??? Pulled out and smoke stopped, so I thought, ‘hey, lets see if this is really fixed, I’ll try the steady state 3500rpm test’.... a few miles later, coasting back into town with what appears to be another blown headgasket..... God Damn It. I did nurse it home this time, so did not need AAA.

Definitely coolant in the exhaust manifold; no coolant in oil, no oil in radiator. No visible external leaks from headgasket. Lost about 3/4 gallon of coolant (which makes a surprising amount of white clouds billowing behind your car down your street. Classy.). I will have to pull the head again, but getting pretty good at it. I expect the headgasket is blown. Again. Hope I didn’t warp my new (to me) head.

I’ve searched MLS gaskets, head gasket sealant, turbo headgasket issues, etc, etc, etc.

So thanks for listening to my tale of woe and ignorance. What should I do—— Goetze headgasket? MLS headgasket? Get the head and timing cover resurfaced? What is causing this? I’d think the steady state driving would be a non-issue. Not boosted at that point. Kind of important to be able to go down the interstate without spewing white clouds of hot coolant on everyone.

I just want this to work. The motor easily pulled the car up hills in 4th gear that I used to have to shift into 3rd gear. It really felt great. I actually shouted out the window with happiness at that point. Then I have this issue. I need some help. I can’t find my specific issue in my searches. Any input would be most appreciated.

[320iAman]

You can check for warp-age with a straight edge and a flash light-I doubt it warped already. Sounds like you need to step up your game to a stronger head gasket an MLS or a Cutting Ring Gasket, downside to cutting ring gasket is that it cuts into the Cylinder Head Deck for extra strength. You may want to consider ARP head bolts and nuts as well.

Ireland Engineering MLS

https://www.iemotorsport.com/product...ad-gasket-m10/

We don't have woes here just Giddy up and Goes

Randy

[Vermont320i]

Thanks for the quick reply, Randy. I will get an MLS ordered up right away. Any trick to those—-I’ve read increased torque on head bolts needed, and copper gasket seal on each layer, or dry, or ???

[320iAman]

From what I have read there is no need for sealer,, now the nuts & bolts --in order to use an MLS gasket you need to decrease the surface roughness of the head deck and block deck from composite head gasket surface roughness. What this means is finer and finer sand paper. Surface roughness is like a saw blade--smoothing it out is flattening out the sharp tip cutting edges to plateaus or table tops. Ra u inches. 30-80 Ra u in for MLS surface sealing , p220-p280 Sandpaper 68-59 Ra u in--Matador(Germany) is a good brand and available. I was tracking a M10 cutting ring gasket from elring on eBay -- it disappeared and was about $80/ free shipping, advantage same roughness as Composite-disadvantage slightly cuts into the cylinder head deck for sealing power. The Firing rings have a edge on them that is installed upwards.

https://www.felpro.com/technical/tec...ce-finish.html

AbrasiveSurfaceFinish.jpg


Randy

[Vermont320i]

If smoothing needed, how? Local machine shop, or is that a DIY with a thick glass sheet and superfine sandpaper? Head, of course. Not sure as to block. Is there a how to somewhere?

Oh, crap. I think I might see my problem here. I mis-read the torque specs for head bolts. The Haynes manual for late model e21 has 25-32 ft lbs, 49 to 52, and 56 to 59. Blue Service Manual has 25-32, 49-52, 56-59, with 4th step of 56-59 again. For some reason, perhaps poor reading glasses or just being a damn fool, I know I torqued to 30, 45, and 50, thinking I was in the ranges for the 3 cold engine steps.

That might be my problem.... what do you think? I’m going to try that first.

[autox320]

If smoothing needed, how? Local machine shop, or is that a DIY with a thick glass sheet and superfine sandpaper? Head, of course. Not sure as to block. Is there a how to somewhere?

Oh, crap. I think I might see my problem here. I mis-read the torque specs for head bolts. The Haynes manual for late model e21 has 25-32 ft lbs, 49 to 52, and 56 to 59. Blue Service Manual has 25-32, 49-52, 56-59, with 4th step of 56-59 again. For some reason, perhaps poor reading glasses or just being a damn fool, I know I torqued to 30, 45, and 50, thinking I was in the ranges for the 3 cold engine steps.

That might be my problem.... what do you think? I’m going to try that first.

Beers from the garage, heres my input.

Most updated is with newer headbolts (longer shank for rocker shafts) and updated 44 ft-lb, wait 15min, +33deg angle, (additional +25deg angle after engine temp cycle; can do after first cycle). Angle torqueing the head is much more consistent clamp loading.

Far as copper spray that really does nothing. Like spray paint. The idea comes from the days of bad porous gaskets and slight imperfection surfaces of old motors. Spaying or painting with shellac to make a flatter surface getting a better seal.

I spray liberally loctite 99ma on both sides on my gaskets. It's a gasket maker glue sealer. Let setup for 10min or so to allow the aerosols to evaporate then lay on there. If MLS this 99ma spray is what others use. You'd have to drill out the rivets and spray coat each layer then rivet back together. Some turbo guys have done this and it works. The MLS gasket company has put sealer on some newer gaskets but from my understanding its only effective if a thick enough MLS gasket so the layers are in the stack.

Last but not least I mean 8psi isn't much and others here have run much more than that even with stock components. So yes look at surfaces carefully. But all else fails can o-ring the block using a Isky tool. https://www.summitracing.com/search/...s?fr=part-type

Plenty of turbo guys o-ring to seal the combustion side of things with high boost.


my post showing the gasket spray, and updated headbolts
https://www.bimmerforums.com/forum/s...0#post29890630

[autox320]

A obvious one should be tuning. Someone will ask what timing are you running. Fuel control, AFR's midrange cruise and WOT. If too hot timing under boost and incorrect fueling it won't matter what combo is put together. Could oring the block and you'll eventually destroy rod bearings etc. Just thinking out loud but usually first on everyone's mind should be the tune.

[Vermont320i]

Dang, that is some pretty motor work on that thread, autox320.

Oh, and I tried the Hail Mary idea of re-torque. No go. HG too far gone. My neighbors think I am burning down my garage! But I do think my torque stupidity was a key component here. Maybe with a Goetze head gasket and proper torque it could work. The boost is really low. Not sure if I am ready skill-wise to sand the decks and install an MLS. Of course, if the Goetze gasket fails it will make another HG job, which would probably actually make me cry.

Options: install better standard gasket, new head bolts, with proper torque; OR
Cutting ring gasket, new head bolts, proper torque; OR
MLS gasket, ARB studs, and a smooth finish on the mating surfaces. Proper torque (this is my ‘note to self’) I know the head can be done on a glass plate, but what about the block? I can’t picture that, in-car.

[autox320]

Dang, that is some pretty motor work on that thread, autox320.

Oh, and I tried the Hail Mary idea of re-torque. No go. HG too far gone. My neighbors think I am burning down my garage! But I do think my torque stupidity was a key component here. Maybe with a Goetze head gasket and proper torque it could work. The boost is really low. Not sure if I am ready skill-wise to sand the decks and install an MLS. Of course, if the Goetze gasket fails it will make another HG job, which would probably actually make me cry.

Options: install better standard gasket, new head bolts, with proper torque; OR
Cutting ring gasket, new head bolts, proper torque; OR
MLS gasket, ARB studs, and a smooth finish on the mating surfaces. Proper torque (this is my ‘note to self’) I know the head can be done on a glass plate, but what about the block? I can’t picture that, in-car.

New gasket and bolts with angle torque updated method is all should need IMO; IF the block and head have been decked milled to clean up. Most shops should clean that up with more than acceptable finish. I'd definitely let a machine shop do surfaces even though I have braved diy myself. If don't have to thats the area I pay a competent shop to do. VR gasket is not as good as geotze or elring true. VR lacks the sealer around areas. But I'm even using VR gaskets in my builds, the best practice IMO is using the 99ma spray on them. My street cars don't weep and use the same technique.

Thanks on my thread. It's a fun project. Motor is just over 13:1 all motor build. VR gasket and no issues yet. Just saying it's all in the prep, and I like my machine shop guy .

[Vermont320i]

I have a machinist friend who could do the head, but block is not coming out of the car. I’ll try a cut ring gasket from elring and the 99a sealant, and new bolts.

Thank you, will update!

[autox320]

I have a machinist friend who could do the head, but block is not coming out of the car. I’ll try a cut ring gasket from elring and the 99a sealant, and new bolts.

Thank you, will update!

In that case lightly clean off the block deck surface with a green 3m scrubber by hand. Once clean put a machinist ruler across the surface on it's edge and try to put a light behind it. If see light theres a gap use feelers under edges if unsure. Either way even if .001" needs to be decked to clean up. I know it sucks but must be flat to seal.

[dukedkt442]

As stated, I'd check the head for being straight/true, especially after the temp spiked. IF the head warped slightly as a result (including possibly from under-torquing earlier), it'll never seal without being milled at a shop. Which, of course, opens up the prospect of figuring out how much it needs to be milled based both the head's need, and also the availability of thicker head gaskets. New bolts, especially ARPs, are a good idea also. Probably also a good idea to calculate combustion chamber and compression, who knows if any previous milling/decking has been performed? Just things I could think of to check out for, to make the 3rd time a charm.

[Vermont320i]

Will definitely check head for flatness as stated, and compare head depth to standards in service manual. Good point about unknown history. Thank you all for advice.

[320iAman]

Checking for Straightness is not difficult at all, the Block is checked the same way,,the feeler gauge used is 1 to 2 mm it should not go under the straight edge and you look to see if any light come under the straight edge, the middle area is where generally the warp-age is,,Glue the wet/dry sandpaper with correct Grit on a flat surface--I used 3M Super 77--I used a large panel mirror--flat as well--wet the sandpaper with water then push and pull the bottom of the cylinder head back and forth---its very fast to get the Ra's your looking for.
DSCI0534.JPGDSCI0538.JPGDSCI0549.JPG

You'll have to plug up all the holes,since your head and block is loaded up,vacuum up particles after each push and pull, this has done before with no future problems, the devil is in the detail, I'd fill with rags, then use a cardboard cutout for each hole that is oversized and push it in.

I disagree with Permatex Copper Spray, I used it with Victor Reinz Composite head Gasket, Metal Paint any color will work as well--since the METAL paint is wet with binders it sticks to the METAL surfaces really well--the metal in the paint transfers heat much better than the Composite material,, like I said before its a club thing.

The alternative in the smoothing process to get Ra's down to MLS smoothness is a complete tear down,, thats the bad news-- now the good news--GET a FEL PRO MLS gasket or one like it--the smoothness required is 80 Ra which is where you are at using a composite head gasket.. Follow instructions from the Gasket maker as too sealers or not with MLS-Viton Surface-call them and talk to them.....They'll give you the ins and outs of it...

Cutting Ring Gasket is your go to if you cannot get a MLS like Fel Pro mentioned above in the link and decide not to do the sanding, check for straightness, I used an Empire Level--Home depot has them and guaranteed straight ect,, USA Company.

Pelican Parts---BMW Head Gasket with Cutting Rings - 11120035273 - Elring Klinger 248.801 $90.75--ships Monday in stock
This fits your 1981 BMW 320i Coupe
Quantity in Stock: 13
Time to Ship: Ships Monday
Weight: 0.45 lbs.
Warranty Info: 2 Years / 24,000 miles
Application Notes: (1.50 mm).

Brand: Elring Klinger


Associated Part Numbers: 11 12 0 035 273, 11-12-0-035-273, 11-12-0-035-273-M30, 11.12.0.035.273, 11120035273, 248 801, 248-801, 248.801, 248801, 4041248069400



https://www.pelicanparts.com/More_In...assCat=Y&null=

lol, Check the Boost Limits for blow bye for this Cutting Ring Gasket - Pelican parts has technical support for these questions phone them, then report back--Roberts Words,,

Randy

Quotable Quotes:

I didnt Miss something, I'm a Mister.

[Vermont320i]

Thanks, Randy. Great info.

[320iAman]

Sure, Here is the same gasket for $67.75,, Parts Container--Huge seller of parts on eBay, I have bought several items from them no problems, fast shipping..

s-l500.jpg

https://www.ebay.com/itm/For-BMW-E10...NnJ5#vi-ilComp


Randy

[Sleepyhead97]

Parts container is great

[320iAman]

I looked into on turbo Boost limits of Elring Cutting ring Gaskets, from what is said and being used you should have no problems with 8 psi boost and stock head bolts if you dont go MLS,, ARP Head bolt conversion is available also.


Randy

[Vermont320i]

Thanks, Randy. Cutting ring gasket and BMW head bolts on order. I’ll pull the head tonight and check it and block for flatness.

[320iAman]

Sure, When running a turbo , 1st thing that pops into my mind is "airtight" small leaks are not your friend-study vacuum testing if your intake and exhaust systems hold vacuum your good to go--with all else good. Torque on head bolts have 3 stages 25-32 lbf-ft,, 49-52 lbf-ft, and 56-59 lbf-ft let rest for 5 minutes or so on each stage before going to the next,, every year I loosen the head bolts 1/4 turn and then torque to 59 lbf-ft--this keeps the deck surfaces flat to the gasket and helps alleviate warp you may want to do this every 3 to 6 months and after 500 miles or so on this job.. The head bolt holes and threads should be cleaned and a light oil put on the head bolt threads--does not change the torque--further the head bolt washers have convex & flat side, the flat side goes down on the cylinder head and torque each in order shown in Haynes ect.

Randy

[OLD MAN]

Looked up the 2002 tii turbo M10. Compression is listed at 6.9 to 1.

May want to check and see if your head has been surfaced ( more than once or twice). Turbo engines need to start with lower compression then a stock non turbo engine.

Personally if i built a turbo engine I would use studs and torque to a higher torque then the stock specs call for.

Turbo M10's on this forum have been troublesome builds.

[Vermont320i]

Some very good points and definitely something to think about, OM. Thank you. I can’t find the cylinder head height spec to check if it has been ground down too much. Would a +.3mm head gasket help that? I have picked up a stock 1.5mm cutting ring gasket, but given situation with the head (see below), I’ve got some time to buy parts. I will research the compression ratio issue.

I just took the head off. Cracked at #3 cylinder, exhaust side. Pretty sure that wasn’t there when I installed it! I’ll contact CHI tomorrow, see if we can work something out—- I know they have recently received a core (from me....). Really glad its not my daily driver. And of course, some adversity will make my eventual success much more satisfying.
0B858704-BEA8-4A30-AAAC-273E07485D55.jpeg

[Vermont320i]

26DCED2C-FBEA-47FA-A3A1-AC91C9BB2D66.jpg It looks like there are some small stamped numbers on the head- would that mean it hasn’t been cut before?

[320iAman]

Not generally,, You measure it.

From Aera-Engine Rebuilders Association

Liter CID Vin Model Year
1.8 108 M10B 320i 80-83

Casting numbers: Head # :1268721

new height 5.085-5.090 ,,min height 5.063
intake height 1.645-1.655 exhaust hgt 1.645-1.655

Notes: VIN M10B18, EFI 320i

If it never has been resurfaced its height will be 5.085-5.090 in, total amount of resurfacing height available @ 5.090 is 5.090-5.063-- .027 in--27 thousandths of an in or 2.7 hundredths of an inch.

Yes that can be welded and made new. Aluminum Welding. CHI has a warranty exercise it , if its still in warranty.

What Daryl(OldMan) is saying is flat top pistons are generally used when going turbo here....lower compression pistons..

Using Higher Compression pistons than 8.8 to 1 owners here have gone with 1977-79 2.0L Crankshaft which increases the stroke from 71 to 80 mm and bumps HP to 125 - 130 area.

Higher compression pistons can be used in turbo , you'll need to prove each specification or use a build someone has done and had success with it.

Right now your testing your build and learning from it.

Randy

[Vermont320i]

And I am having fun with it——thanks for all the help guys!
I’ll get the info to CHI and see what can be worked out.