1HDT Engine Rebuild

[lynchmob]

Boring 040 over with matching oversized pistons & rings is the optimum solution from what I've read. You just can't get them for this engine - even in Japan.

Are you sure about this? Where have you looked? I may have a set of pistons for you. I have to double check that they are 1mm though.

 

[mountaincruiser]

Thanks lynchmob. 040 (1mm) pistons and rings can be had from Engine Australia
Free shipping too.

Rebuilder whants an additionl $150 per cylinder to bore & sleeve plus $40 per sleeve - thats on top of orginal tab which inluded boring to oversize 040. Doesn't add up.

So options are to wait another few weeks for parts from Oz and go 040, or sleeve and get shafted price-wise. Why is boring sleeves so much more expensive than oversizing?

I made the decision to rebuild because I wanted to do this right and forget about it. Otherwise, I would of slapped a used motor in. 14 weeks later I'm still at square 1. Despite the frustration, rising cost and time - what's the best option?

 

[roscoFJ73]

I still cant see why he needs to sleeve all the cylinders. The sleeve is stationary so it is not out of balance.
If it was me I would go to the next oversize on 5 cyls and resleeve number 6 to the same bore.

Or if the bore on the other 5 cyl was in very good condition ,I would put the pistons back in and just resleev number 6 back to the standard size.

 

[gbentink]

I have a set of quality aftermarket 1mm (0.04") 1HDT oversize pistons with steel inserts in top ring complete with rings and gudgen pin. All new, PM me if you want them, I can post them to you

 

[gbentink]

And for the record, no visible scoring = no need for sleeving. It will have to take your fingernail off to be that bad.

Highly unusual (as in, almost unheard of) to crack a ring in one of these.

By the way, there is no way that the turbo could in any way contribute directly to crank case pressure. Of course, extra boost means extra blow by, but at idle for instance, there isnt any boost to speak of. If a mechanic suggested you to do this, then they only want whats in your pocket.

 

[BC40]

Seems weird (at best) that when you took the head off and saw the bores looked good that three of the cylinders need sleeving. A 0.25mm deep groove is pretty obvious and to say that three of the cyl have even deeper scoring (to need more than 0.5mm oversize) doesn't add up.

 

[mountaincruiser]

Thanks for the offer on pistons Gbentink. I have a set coming from Engine Australia thanks to Lynchmob. Thats one cool dude.
When I get home in a week I'll go over and take pictures of the scoring & broken ring. I'll post'em up for you all to see.
Right now I'm getting all my info over the phone, so can't comment on scoring. Could it be wear though - not just visible scoring (?). I'll find out....
I did see the ring in #6 though and it sure as h*ll split in 3 pieces.
As for my turbo - it was done, cracked housing and all. Don't know if it's early demise was related to engine. I was convinced at the time that the blow-by spewing out of the air intake was turbo seals. It was partly - but after I replaced the turbo - went to check oil level and the oil cap flew right out of my hand. Lots of pressure! So - compression test-->#6 half-->rebuild. Had nothing to do with any mechanic. Just my bad luck! Imagine...... so now everything under the hoods get'n the full-meal-deal.
Milo

 

[mountaincruiser]

Be cool if someone could explain if & how turbo failure (excessive heat) was related to my #6 cylinder issues.

 

[Jimmy B]

Be cool if someone could explain if & how turbo failure (excessive heat) was related to my #6 cylinder issues.

Depending on how badly the turbo seals/bearings were leaking you may have been drawing extremely hot exhaust gases +1000 degrees into the motor,#6 was the worst hit,maybe because it is the rear cylinder and was not able to be cooled properly.

 

[bigbrowndog]

I work in the heavy equip industry and although am not an engine specialist i have done my fair share of industrial rebuilds. From what i have been taught and heard if you are going to boar or go oversize you do ALL the same. Any other method will cause an unbalance, think about your volume-metric differences. And as far as re sleeving these i think since the 1hdt is a dry sleeve(not meant to be "just replaced") it would be very expensive to do and where are you going to source the sleeve? this is much different from a wet sleeve engine where the sleeves just push out. I may be wrong as i have been before , just voicing my .02 as i have never heard of intentionally having different sized boars in an engine in the 8 years i have been doing it.

Cheers, It is fairly common practice to fit one oversized piston which is usually lightened to be the same as the others to cut the cost of a rebuild here. If the cross hatching and bore is good in 5 cylinders there is not a lot to be gained by reboring good cylinders for no real gain.