JFettig
Vendor
if you know how to use them, telescoping gauges can work very well in combination of a good micrometer. I frequently see people mis-using them, it is sometimes hard to get a good measurement on them if you can't feel it just right.
Ok - lots of comments to address here...
All of the other things that the car needs (suspension and such) are definately needed and way beyond overdue. Then combining the engine repair/replacement now and everything associated with that, I just wanted to make sure that I wasn't "polishing a turd" here. The overwhelming consensus is that it should be fixed and I agree with that. This car has done everything I've ever asked of it, thousands of miles pulling trailer, my dependable daily transportation, excelllent mileage (52+ MPG average over lifetime). I know what this car is/is not and buying something new/used would start that learning curve over and besides that I like the car .
That said, now to decide how/what to repair this thing. It sure seems that lowering the compresion would help keep peak cylinder pressures and piston temps down. Lower compression will generally loose thermal efficiency but might prevent this from happening. ~18.5:1 would be about as low as I'd want to go to insure good starting in the winter. Any opinions on a thermal barrier on the tops of the pistons - Maybe keeping the 19.5:1 CR for good starting and a thermal barier would make the pistons live? I'm aiming to improve power in the 1000-2000 RPM range so this is the time to make any changes/improvements to support that.
I'm assuming that this failure was due to thermal stress on the pistons, most likely from towing and resultant operation at continuious high loads for hours on end. If I get it apart and find the oil squirter plugged on #3 pistion or some other evidence of another cause of the piston failure, I'll let everyone know. EMP's during the heavy trailer towing are equal to boost and IAT's are ~50F over ambient. A larger oil cooler would probably be a good idea (no oil temp gauge, but will be getting one).
My trusted mechanic is adamant that the block should be bored/trued up and that it's probably not round and would have trouble sealing the rings if it was just honed. I'm going to try and get a 3-4" micrometer and bore gauge to see if the cylinder is true enough to hone or not. Given the marks on cylinder 2 in particular it could be either way.
What about a complete engine swap? A PD150 and 6 speed from across the pond?
Are there any 16 valve motors that will more/less go in?
A CR without all the emissions stuff would be cool as well?
I guess all the statements I've made about "Well, it has not blow up yet" are no longer valid .
If I can just hone the bores for new pistons/rings, then I don't have to remove the engine from the car saving a fair ammount of time/effort. If it has to come out, it will, but being generally lazy, I'd rather not if I don't have to.What is the down side to bore out the block? Cost of new pistons and the machine shop cost? At least you would know the bore is true. And you are going to buy some new pistons anyway, right?
Just asking - not advocating.
Also, what needs to be done to boost the power between 1000 to 2000 rpm??? Smaller turbo?
Yes, they are basically the same. PD150's are 18.5:1 CR, the ASV's are 19.5 like ALH's.Are the PD150 and ASV pistions interchangable? Bowls in the same location, etc?
I assume the PD150's have a larger bowl to drop the compression? Any idea what the CR drops to on with the PD150's
Swaintech for coatings I assume? Anyone else who does coatings like this?
I think I have all the measurement equipment lined up and will try and measure the bores tonight.
I've wanted to put a heavier flywheel in for a long time - figured it would smooth things out quite a bit.
Regarding lugging and stress on the internals, I think the pistons and rods should address a lot of that. I'm not looking to make 200 HP at 2000 RPM, but just extend the power curve down the RPM range. BMEP's are significantly lower (half) than some of the 200+HP 400+ft-lb TDI's out there.
Maybe to ask another loaded question....OEM head bolts or ARP's?
Are ASZ and ARL pistons the same or are they actually different?
Any theories on why a change in compression ratio would change the powerband?If you're set on the low rpm power, as in 1000-2000, the lower CR will destroy those dreams... I went down to 18.7XX on my build and it has the torque of a 2.slow under 2000rpm.. 2500rpm+ is a totally different story however.. A bit hard starting in the cold but nothing major.. Some of my lack of low rpm grunt is from the 2260, but regardless of the turbo, there's NO off-boost power at all...