Mustang Tech

So this Dart shork block is just junk, So far I've spent $9K plus on it and now it looks like cyl 8 is porous/cracked.

Both heads pressure tested OK and cyl 8 has lowest compression and has those steam cleaned looking marks in it I posted in the other thread.

Dry cold compression test results:

1. 150
2. 157.5
3. 150
4. 155
5. 155
6. 150
7. 160
8. 135-140

Shanup I am not keen to go back to PLR as the cost for the first rebuild was outrageous. You use Fataz correct? Have you had a block sleeved by them?

Thinking of going 363 if I have to machine it yet again.

How old is the Dart block? Surely they should warrant it?

You only get 6 months on a short block. That was gone before I got it in the car the first time.

Also be careful as VPW will only give you 3 months.

That's terrible. Do you think the block was bad, or some other issue?

Hi,

I think there may have been casting issues/impurities in the block.

Either way I've taken a closer look today and you can feel those strange looking light marks so it will at the very least need a rebuild.

PLR charged me over $4K last time to disassemble/hone/reassemble and I really don't want to drop that much more into this block.

I'm thinking the next step is 363 keeping crank and rods, machining block and getting new Mahle pistons.

Anyone want a low Km set of 347 forged Mahle flat tops?

Ouch, how many kms have you done with it?

less than 2000

Yeah wow that's no good. Maybe I'll just keep reading using stock blocks ?

363 pistons ordered

lukep6470 wrote:So this Dart shork block is just junk, So far I've spent $9K plus on it and now it looks like cyl 8 is porous/cracked.

Both heads pressure tested OK and cyl 8 has lowest compression and has those steam cleaned looking marks in it I posted in the other thread.

Dry cold compression test results:

1. 150
2. 157.5
3. 150
4. 155
5. 155
6. 150
7. 160
8. 135-140

Shanup I am not keen to go back to PLR as the cost for the first rebuild was outrageous. You use Fataz correct? Have you had a block sleeved by them?

Thinking of going 363 if I have to machine it yet again.

I build my own, but Yes Woody at Fataz will build it, Sounds like it may need a sleeve, but the bores are super thick on these cant see how it could have an issue really. Woody and I use Wynnum engine for machine work. Bring it down and I'll have look. Brett can crack test it at Wynnum. I think it may have just washed the rings out. Easy to get it checked though

Think last sleeve I had Brett do was about $100. Plus you'll have to bore to 4.125, and redeck it

Did you do a wet comp test? You wouldn't expect that sort of differentiation on a new engine but ive seen more than that on more used engines that run fine.

Regardless, you probably want to get to the bottom of what is causing your problem before you sink more money into it.

Have you had the block crack tested? check your oil galleries, maybe that cylinder has been starved for some reason. At 2000km you would have barely run in the thing, what run in oil & bed in procedure did you use (there are multiple schools of thought here too...)

I'm no engine expert so please don't take it the wrong way, but you only have around 10% deviation in compression test pressures, which isn't a lot on what is a very crude test that is only indicative of a problem that can be caused by numerous factors.

Yeah I dont think there is much wrong with it. the bores are very thick in these blocks, I think the marks in the bore are do to with it burning some water, or its been running real rich and it washed the bores. You can bore them like 80 thou over 363, they are pretty stout. Worse case it needs a sleeve which is about $100 fitted.

Hi,

Thanks guys, BTW on closer inspection those light marks look like the surface of the bore has flaked off!!! The are rough to the touch so I would expect that cylinder wouldn't have much live left in it.

Every time I started it coolant went in the oil so I was keen to run it long enough to warm it up.

Shanup - So it will be a few weeks now as we have home renovations going on and also I have to spin the car 180 in the garage on wheel dollies before I can pull the motor.

Had also just got the AC gassed, sigh.