Need 2.7 Advice as Losing Ethusiasm

SalParadise · 05-21-2018, 01:12 PM

Well I have been cleaning and re-doing the '75S. The engine is the original 2.7 that was rebuilt by the previous owner with a Carrera oil pump, TimeCerts in the block, rebuilt heads, etc. It was actually done well, but he cheesed out and redid the original KS Alusil cylinders and re-ringed it. The engine has about 11K on it since this rebuild.

I was going through every detail and seal, not to mention Carrera tensioners and oil tubes. All of the valves were adjusted right on even after sitting.

While turning the engine over by hand something did not feel right on one cylinder. I kept looking and finally got a good view of cylinder #5. Seems the piston is sort of breaking up (deep scores in the wall) and some other scores. I have read on here that people put aluminum pistons in Alusil in the '90s and the pic on here looks identical to mine.

Needless to say it took the wind of out my sails. I know it's an old car, and I can fix it, but right now I want to fix it sooner than later and start driving.

Question is, do I invest in an entire set of Mahle 2.7 Nikasils and put them in and be done with it? Everything on the engine looks great, but that one cylinder is going to break up in a matter of time I suspect.

I would like to do this as quickly as possible - not the cheapest - but would like to keep my engine and just fix the cylinders/pistons.

Would like to know what people think as I would like to have this done and not have it drag on. I am sure others have been there.

Thanks

Steve@Rennsport · 05-21-2018, 01:46 PM

Hi,

It sounds like you need new P/C's (can't tell without pics), but my main concern is debris in the engine from the piston failure.

One would need FAR more detailed information before offering specific advice, however you should be able to replace the Alusil set with Mahles.

SalParadise · 05-21-2018, 02:07 PM

Steve thanks for the reply.

Funny thing is that my cylinder #5 looks exactly like this photo - damage and all. It was taken from speedo's thread on his 3.0 MFI teardown. He said that someone put aluminum pistons in re-honed KS jugs. That I have in the engine is Alusil KS cylinders and when I asked the old owner of my car he said he just "re-ringed" it.

So there you go. The rest of the cylinders look OK but this one is smoked exactly like this one. Also #2 cylinder has similar scoring, right across the way from this one.

SalParadise · 05-21-2018, 02:09 PM

The scoring on mine, as his, is at the 6 o'clock bottom direct bottom position, 12 o'clock being top of the engine.

Trackrash · Trackrash's Garage

It might be worth looking for a good used set of Mahle cylinders, you never know, there could be some around.

Another choice would be to have your cylinders bored, plated and matched to some JE or CP pistons. Then you would have a 2,8.

pmax · pmax's Garage

Sorry to hear this.

Scoring like that must have been detectable when the engine ran prior to the refurbish. Were there any symptoms ?

SalParadise · 05-22-2018, 03:22 AM

Quote:

Originally Posted by pmax

Sorry to hear this.

Scoring like that must have been detectable when the engine ran prior to the refurbish. Were there any symptoms ?

Strangely enough, not really. It ran - did not smoke. However there was some blow-by. This was probably the only symptom.

Matt Monson · 05-22-2018, 05:35 AM

Make lemonade. Rebuild to RS spec with mahles.

Eagledriver · 05-22-2018, 09:50 AM

The good news is you might not need to split the case. Need to determine if you got metal pieces in the engine. Maybe cut open the oil filter. Check out the bottom of the oil tank. If no metal in the engine, you can just put in new or used pistons and cylinders.

-Andy

SalParadise · 05-22-2018, 01:15 PM

Quote:

Originally Posted by Eagledriver

The good news is you might not need to split the case. Need to determine if you got metal pieces in the engine. Maybe cut open the oil filter. Check out the bottom of the oil tank. If no metal in the engine, you can just put in new or used pistons and cylinders.

-Andy

Andy, yes, no metal at all in the case. None in the filter or bottom screen area.

I would just like to remove the top end, replace the pistons and cylinders with Mahle Nikasils, and be done with it. I am hoping that this would be a week job.

Matt Monson · 05-22-2018, 01:35 PM

If you can find a decent set of jugs, I’ve got some 8.5 RS pistons, new, I would sell.

SalParadise · 05-22-2018, 04:31 PM

Quote:

Originally Posted by Matt Monson

If you can find a decent set of jugs, I’ve got some 8.5 RS pistons, new, I would sell.

Thanks Matt - I'll see what comes my way. Someone stepped up and is giving me a deal on new Mahle pistons and cylinders for a great price. I'll see where that goes...