High HP on stock headgasket

[someguy2800]

Thought I would share this for group knowledge. On my last motor configuration I decided to try a stock gasket with no orings and S54 head studs just to see what would happen and what the limit on that would be. As you'll see below the limit was just about found. I pulled the head off today to make some motor changes and put in a cut ring gasket for safety reasons, and found the gasket was starting to push out on cylinder 2 and 5.

Just to recap the setup was a 2.8L built off a M50 block with stock bore wiseco pistons, 11.8:1 compression, stock headgasket, 11mm ARP head studs, and E85. The gasket is just a $30 victor reinz from amazon. I don't recall what the studs were torqued to but probably 100 or 110 ft lbs. It has a ton of passes on it at 28 lbs of boost and a dozen or so at 32 lbs. Probably about 800-850 whp.

Hard to see in the picture but normally the gasket is about a MM or so from the bore, but on cylinder 2 and 5 its about 3mm. Don't mind the clover leaf shape of the fire ring, they come that way stock to clear the valve reliefs in the chamber.

I don't know if it would have continued to push out and eventually fail, or mabey it would have stopped and stayed that way forever.

[vollosso]

Very cool.


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[Beer+Oversteer]

Thanks for justifying me turning up the boost on my stock motor!

Just kidding. 12 psi will have to do for now.. once I have a spare motor I'll be sure to test the limits of a fully stock m52 (over 300k miles!)

[Robocop]

is this from the power going on in the cyl or from the block/head flexing you think?

[someguy2800]

is this from the power going on in the cyl or from the block/head flexing you think?

Cylinder presdure no doubt. The reason I decided to get a cut ring for it finally is I’m looking to make another couple hundred hp and I was concerned it would push the gasket out and blow the radiator hoses off going 150. Also time to retire the stock non vanos rods.

[someguy2800]

Now we know the limit of non vanos rods too lol

[somebody5788]

So you're saying that me running stock with normal ARP studs up to 450whp isn't really that big a deal like everyone was making it out to be for so long?

[jakermac]

Am I seeing that right? Does that rod have a bit of an S bend parallel (not anymore) to the beam?

[vollosso]

I pulled apart a 600whp/550wtq block that had been together 2 yrs and ran fine. Every rod was s’ed


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[vollosso]

I pulled apart a 600whp/550wtq block that had been together 2 yrs and ran fine. Every rod was s’ed


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[someguy2800]

So you're saying that me running stock with normal ARP studs up to 450whp isn't really that big a deal like everyone was making it out to be for so long?

If the head and block are surfaced flat with a new stock gasket they will hold a lot. The blocks settle over time and develop high spots as the casting relaxes. If you surface a block they always have high spots around the head bolt holes.

- - - Updated - - -

Am I seeing that right? Does that rod have a bit of an S bend parallel (not anymore) to the beam?

yeah, this is the worst but at least 4 of the rods are bent. The piston is scuffed a bit on this one and the top ring is pinched but I think i can save it.

[somebody5788]

If the head and block are surfaced flat with a new stock gasket they will hold a lot. The blocks settle over time and develop high spots as the casting relaxes. If you surface a block they always have high spots around the head bolt holes.

It gave every appearance that the head was decked properly but unfortunately I have no idea if they even touched the block. The gasket was replaced before I bought the car but I've put 19000 miles on it and 5000 on boost hehe.

[someguy2800]

Rod from #5.



scuffs on the piston crown from bent rod. The piston mic'd out okay and I cleaned it up a bit but the rings were fucked up so I will have to order a new set for that cylinder



Piston #4 has a few detonation pits. The last pass at the track was at 32 psi and it almost went on the back bumper. I was too busy enjoying all the freedom to look at the gauges but the datalog said it was like 14:1 AFR the whole way down the track so I think the fuel pumps sucked air or something and it went way lean which is why it bent the rods and was pushing out the headgasket

[hsvturbo]

I'm not to familiar with custom pistons and pins, but those pins look to have a large ID, like they are designed for NA? Any plans to beef them up?

[bubbafett]

cylinder 6 is cracked as well, just not as deep. Dang dude. lol

[someguy2800]

I'm not to familiar with custom pistons and pins, but those pins look to have a large ID, like they are designed for NA? Any plans to beef them up?

They are an off the shelf part number so no they don't have the thick pins and they have pretty thin rings also with a 1mm top ring, but they are a turbo piston. Where I really want to be is about 1200-1300 hp at the motor and I'm not convinced an M50 can ever do that reliably so I'm not sure I want to sink $2500 into custom pistons and good rods + machine work just to crack the block every 30 passes. Besides for the damage above, which I think is understandable for going down the track at 32 lbs and being dead lean, everything else in the motor seams to be doing okay. The bearings all looked like new and there was no wear in the pin bores. For the moment I am putting it back together with what I have and will keep the power in the 1000 hp range at the motor. Hopefully it will live for a season at that level and I can sort out where I want to go from there.

I have a 2-1/2 year old girl and we will be having another in about 2 months so I don't really have time to mess with this all the time anymore. I want to get into something that I can run a whole season at 1200 hp and not mess with, and by a whole season I mean like 150 passes because I run the shit out of this car. That was a major reason I went with the th400 trans. I don't think an m52 is up to it.

I think suitable motors would be a built 2JZ, a built S38, or a built LS motor. An S38 would be my top choice but they aren't making any more of them and they are already awfully hard to find and expensive. I would really need to buy 2 of them to have a spare. A 2jz isn't too bad to build to that level and most of my current setup like injectors, coils, turbo, torque converter ect would carry over. An LS motor probably make the most sense to invest in and if you blow one up they are everywhere for a couple hundred bucks. They are also pretty easily serviceable with reusable head gaskets and all that, and they make power at 6000 rpms so they don't need to be too exotic in the rotating parts and valve train. Plus I'm a v8 guy at heart. I don't know, we will see.

[PowerKraut]

The moment you said you are not convinced the M5x will last, i knew its gonna be LS time. Lame.

For sure the most reasonable decision in the long run tho.

[Substance D]

I thought the Elring gasket is supposed to be better than Viictor Reinz. Bigger fire rings or something. I am surprised it lasted as well as it did

Sucks to hear your giving up on the ol' m50. Makes rational sense though

[someguy2800]

The only reason it still has an m50 in it is they are cheap to make 800whp with and people seam to think it’s cool that it’s still bmw powered. Im sure you could make it live with billet caps and sleeves and a welded up head but I’m not willing to spend $15k to be cool when $3k in an LS gives what I want and can be replaced in a week. What’s lame to me is $1200 camshafts and $1000 harmonic balancers. I’m at the point where if I want to go faster I have to spend a bunch of money on top of what’s already been dumped in. I have $10k worth of transmission and drivetrain stuff. The car is good to go low 8’s high 7’s if it just had the right power maker in it.

[someguy2800]

The real problem is I didn’t anticipate how fast cars would get lol. I built the car to be a 800whp mid 9’s car, which it did. Problem is when started a 9 second street car was exrodinary, and when I finished it was the norm.

[hsvturbo]

The only reason it still has an m50 in it is they are cheap to make 800whp with and people seam to think it’s cool that it’s still bmw powered. Im sure you could make it live with billet caps and sleeves and a welded up head but I’m not willing to spend $15k to be cool when $3k in an LS gives what I want and can be replaced in a week. What’s lame to me is $1200 camshafts and $1000 harmonic balancers. I’m at the point where if I want to go faster I have to spend a bunch of money on top of what’s already been dumped in. I have $10k worth of transmission and drivetrain stuff. The car is good to go low 8’s high 7’s if it just had the right power maker in it.

What would be your $3000 LS recipe that could crank out 1200 hp? I haven't priced out a built engine yet but I would think heads, cam, valve train, piston and rods would be closer to $5k.

[someguy2800]

What would be your $3000 LS recipe that could crank out 1200 hp? I haven't priced out a built engine yet but I would think heads, cam, valve train, piston and rods would be closer to $5k.

Pistons, rods, cam, springs, pushrods, ls6 intake, balancer, and I would do a quick port on the heads myself. I would surface the head and block at home and probably get it bored .010” over. Probably upper 20’s boost and spray a 100 shot on top of it.

[jrode34m5]

And if it was an s38 what would be the recipe for 1200hp ?


Thanks

J Rod

[PowerKraut]

And if it was an s38 what would be the recipe for 1200hp ?


Thanks

J Rod

Pretty much in this order ---->

[jrode34m5]

but those guys from sweden make it look so easy to get ~1000 hp from these engines as long as you have the

money and the know how. With money anything is possible.