Probably doing a first start tomorrow. Hope it works. (Cracked cylinder head) Topic is solved

Post by **vtl** » 23 Jun 2023, 09:01

abscate wrote: 23 Jun 2023, 08:51
Anyway, I had given the head to a friend, who...has nicked the head cam bearings
Wait - what engine family are we on here? I thought P2s ran in machine matched cam surfaces for both axial and thrust play - no bearings at all.

B5244S or S2 most certainly.

Cam surface is the "bearing". Which is pity, because you can't replace them when they wear out.

dikidera · Post by **dikidera** » 23 Jun 2023, 09:45

The Engine as per the original code is B5244SG, but that is simply B5244S2 really.

Yes, the cam cover and head "bearings" are machine matched and cannot be replaced. The dent is small i believe I can file it down slightly and hope for the best.
The gaps between the cylinders vary in size. I have managed to fit 0.8mm feeler gauges in some and could only fit 0.55mm in others. I am truly not sure how people managed to easily fit a single size shim in each of them with such huge variation.

Might be able to take pictures tomorrow. While I have extensively investigated for cracked liners, as is common on the T2,T3,T4 etc, I found no such on my NA engine.

The head bolts that I buy come pre-oiled to an extent. However I was given advice to give them a cleaning with a wire brush to remove any debris from the threads but I was also told to oil the underside of the bolt cap which is what really clamps the head to the block.

As for sleeves "dropping" or sinking, thats an entirely different matter and can only be measured with a specialty tool.

Post by **vtl** » 23 Jun 2023, 10:09

dikidera wrote: 23 Jun 2023, 09:45 The gaps between the cylinders vary in size. I have managed to fit 0.8mm feeler gauges in some and could only fit 0.55mm in others. I am truly not sure how people managed to easily fit a single size shim in each of them with such huge variation.

Limestone buildup, need to scrub it off mechanically. Permanent expansion is also possible, but what I saw in two T2 engines was limestone mostly. Once scrubbed off, the gaps varied in 1/100s mm range.

dikidera wrote: 23 Jun 2023, 09:45 As for sleeves "dropping" or sinking, thats an entirely different matter and can only be measured with a specialty tool.

Does not happen in these engines, the sleeves are ribbed and are a part of casting.

Also don't file or patch anything on the machined surface.

dikidera · Post by **dikidera** » 23 Jun 2023, 10:13

I will try to take a pic of the affected part, but if I do not file it down or sand it down, the camshaft journal will definitely get scratched. The amount of filing I am talking about is only to remove that rough part of the bearing surface which catches my nail. If I leave it as-is, that little 3-4mm long piece of material will get shaved down and sent throughout the entire head/engine, in my opinion.

I found this cylinder head image on the internet and I outlined in blue the location of the dent. Look for the top left corner.

https://imgur.com/RNhm9AA.png

Post by **abscate** » 24 Jun 2023, 14:03

Dont sweat a ding on the cam bearing surface. They aren’t heavily loaded and they are well lubed in these engines. The cam is hard steel and will mill off any aluminum chaff

dikidera · Post by **dikidera** » 27 Jun 2023, 03:16

I did as you said and installed the camshafts like that. I will be doing a start today if time is forgiving. Also it's 30c today, humid and my concrete garage is like an oven.

For reference, it looks like this

I only hope I did not cause blown crank seals, I mean the one on the side of the harmonic balancer is easy, but the one on the gearbox side is definitely not.

Post by **vtl** » 27 Jun 2023, 08:28

dikidera wrote: 27 Jun 2023, 03:16 Also it's 30c today, humid and my concrete garage is like an oven.

Me wonders how large is your cold beer fridge?

Post by **matthew1** » 27 Jun 2023, 14:33

The hotter the garage, the bigger the beer fridge.

dikidera · Post by **dikidera** » 28 Jun 2023, 04:24

The block test is conclusive. Exhaust gasses in coolant...again. The warped block route is more likely once again. However I don't have the tools to change the engine, so I have to basically give the car to a shop to get a new engine, have it serviced etc and installed.

Biggest issue is you guys know our 2.4 engines have fairly thin cylinder walls, it's not like they can rebore them much if at all, otherwise even the NA engine risks cracked cylinders...of course this depends on how out of round the cylinder is, but this is a game of chance on what used engine one buys.

Now the shop doing the block test did mention that, if one does not fully flush the cooling system from the old oil/antifreeze mix, it is possible to get false positives with the block test, otherwise 0.002 thou or 0.05mm of warpage is on the upper bounds of allowed tolerances, and even then it's better for the warpage to be as close to 0 as possible.

We did tighten the head not to 130 degrees as mentioned on the head gaskset pamphlet, but around 150 just to be safe...but maybe it did not matter.

And just before I even left for the shop to do the block test, not sure if it was a hose clamp not properly tightened, but the hose came loose and spewed so much coolant everywhere... It was either that....or as the block test showed, exhaust gasses in coolant causing a high enough pressure to blow out the hose.

Anyway, I am very disappointed. In myself, in the engine, in spending so much money in an attempt to save money, only for things to circle back to where they were before I even attempted all of this.

Post by **vtl** » 28 Jun 2023, 08:02

The surface has to be very clean in order to measure warping as little as 0.05 mm.

You didn't show us good quality pictures of the cylinder gaps. Usually exhaust leak happens there. Also how bad are the sleeves out of round at the top?

White block engines are basically unrepairable. While it is theoretically possible to bore the cylinders out completely and install Darton sleeves (if you are rich), but the warped head destroys camshaft journals. That you can not repair easily.

I took a month or two off after rebuilding automatic transmission only to find out it slips in all gears. Did another rebuild, replacing worn new friction plates and biting a bullet and buying a new valve body. Found absolutely nothing wrong in my mechanical work, however in valve body I had rebuilt as well just one plunger was rotated 120 degrees and wasn't closing the oil channel properly. It was a bitter experience, given how painful is it just to drop and lift back the transmission, thanks to interfering subframe, but at the end it turned out well and the car drives like new. You have to fail to succeed.