Melted Piston.

Pistons are now flycut for the 39mm Int valves

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Head has heater port welded

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Hopefully he'll be done with machine work early in the week - I'd like to get the engine together & back in the car before December comes around
 
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I have an interesting thread I am about to post that will bring back memories of this melted piston for Hussein. Check the pics...
 
That's 40 thou (1mm) piston to head (or SQ) clearance, just right IMO.

Using the Scat rods (which are 10thou shorter CtoC) and decking the block for flat worked out just right I would say...

I like the head heater port modification... another way to do it ... I've got a CAD drawing of a thermostat adaptor which incorporates a fitting to route the heater to.... but your way is neat / tidy and doesn't require extending the heater hose at all...

Interesting piston rollover vice your machinist has, grips on the pin... my guys vice has soft jaws that grab on the ring lands and into the ring grooves... means I need to remove rings whenever I want this operation done...

have you worked out your static CR yet??

its all looking good Hussien.... keep us all posted.

SteveC
 
I can follow your suggested method for checking specific clearances once I get the parts back from the machine shop. How to calculate static CR from that, I have no clue - math is not my forte in the slightest. Is the combustion chamber volume a published number or does that need calculating as well? If the process is explained I can probably do the calculations, but it's not something that is obvious or that comes easily to me at all.
 
Head took a very light skim - valve seats being cut. He is using the 33mm exhaust valves, but reducing them about 1mm - original seats do not have sufficient meat to enlarge to 33mm, and he feels that is too large anyway. I trust his judgement.

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Shaved valve guides & port work somewhat visible

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Short Block is ready - head should be ready tomorrow, so Fri hopefully I will make up true TDC & check valve/piston clearances with some putty.
 
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Definitely do the plasticine (bump) clearance check, definitely determine true TDC by the positive stop method. If you are anal about this stuff like me, you will want to measure that the head has been cut squarely, measure that the block has been cut squarely, measure that the pistons sit square in the bores...and measure the ring end gaps of all piston rings.

Calculating your actual CR isn't too hard, just requires some careful measuring, that's all.

Get yourself a small sheet of plexiglass (perspex) that will fit over the chamber / bore. Buy yourself some graduated syringes from a pharmacy, vet supplies etc ...they are pretty cheap... a selection (say 10ml, 5ml and 2.5ml) with graduated markings on the side makes it quicker to do.

Position the plexiglass over the chamber, use vaseline / petroleum jelly smeared around it to help it seal up. get the head so it sits pretty level and mark a couple of points on the plexiglass that fall within the chamber, one is going to be an inlet hole, the other will be your air vent.

Drill the holes out... maybe 2 to 3mm is sufficient...put a bevel on the inlet hole which will help you not spill any fluid and get the tip of the syringe in... put the plexiglass back on. Have a spark plug screwed in and the valves fitted, and both valves closed (if the cam is fitted )

Carefully fill the space in the chamber with fluid, very light oil (cooking oil works ok) kerosene, a mix of both these to get a nice not too viscous and not too runny liquid. Keep note of exactly how much fluid it takes to fill the chamber, do it a couple of times so you know your results are correct by repeatability. For total accuracy do all four chambers but that's not 100% necessary. This is your true chamber volume.

Do the same thing to the flycuts on the pistons...measure their true volume.

At true TDC, determine exactly how much positive deck your pistons have in your block using a good flat edge and feeler gauges....do this to pistons 1 and 4 at least... all four if you can be bothered.

I have another set of exactly the same pistons your using so I can determine the piston ring land volume and piston head diameter for you.

Measure the head gasket thickness of the head gasket you have ... and note the brand and type you have...as we will need to do a little educated guesswork about it's crushed thickness

post all the numbers here and I'll help you do the math....it's actually pretty simple once your shown how.

SteveC
 
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Thank you for the detailed instructions!

The impatient side of me just wants to throw it together & get the car running! I'm going to take the time to check these other elements, in part because I just want to know.


This is what I did with the tensioner pivot casting to allow for coolant drain in the event my stud comes loose when setting the tensioner DTR

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Flycuts

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Worked on my Mum's S70 yesterday after work, so I didn't pickup the parts until late this afternoon, hoping to have time over the weekend to do the partial assembly in order to check valve/piston clearances, etc. just have to see how it goes.
 
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Problem in #1

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Don't know how I didn't see that when I picked the short block up.

Have to take it back & him figure out what happened when he assembled it. Looks very bad to me :-(

I may need another block. No way I'm shelling out for different pistons and all that work again. The large groove is significant
 
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I think there is a strong expletive that needs saying here. Geez.

Really sorry to see that. I hope it didn't mess up the rings on that piston.
 
Bugger... :confused:

best thing to do is stop and go show the guy what you found....

I would stand there while he dropped the piston out to look too...

lets us all know what happens.

SteveC
 
What a bummer

Hey.
I cant believe your Luck... I too have followed this thread and the bad luck magnets are sure on full.
If finding a block is a no go can these be sleeved?
I wish you well dude
 
He is taking full responsibility for the damage, which I was expecting, just wasn't sure what path would be necessary to move forward.

The oil ring is essentially an "I" beam (bloody font), and a edge of the upper beam snapped off & gouged the bore. He will sleeve & rebore the cylinder to spec. He is also going to try and get newer design oil rings and replace all of them with ones that aren't one-piece, he just doesn't like that old design. He pointed out that they are non-ductile, so will always break rather than bend like the other rings. Pic later

hard to see, cracked in area of arrow

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How did you make out with your machinist?

Good Luck,

'PeteX1/9

Sorry I didn't see that you had already stated that the machin shop was taking full responsibility for the damage, which is great news.
 
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Got the call just now. Re sleeved, and new style oil rings on all pistons. Now I can move on with the measurements.
 
Got a little time in on the motor today. I Installed the front and rear covers, gears, oil pump and dist shafts, oil pump, vent tube, oil pan. I'm cleaning & painting parts as I go along , so it's gonna be awhile :)

Also compared the 240 LH2.2 fuel rail to the Fiat L-Jet. I'm going to need to modify the rail, and make sleeves/adaptors for the injector seats in the intake runners. Also have to find 16ohm Bosch injectors (to replace the 2.4ohm stock) in the Fiat flow rating. Anyone know off hand what that is? 160cc? More, or less?

EDIT: Found the answer here:

"the X1/9 use 0280 150 123 which are 148 cc (14 1b/hr)"

I'm fed up with the old FI, and a couple of other threads on here reminded me of that, and it's limitations. LH2.2 maybe old also, but it's a far cry from L-Jet. Doesn't require a crank signal like 2.4 and Motronic, so not hard to integrate with the Allison Ignition I recently installed.
 
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Glad to hear the score in the cylinder was fixable. Mistakes happen and its nice to hear the shop admitted the error and made it right... in fact they made it even better with the improved oil ring!
 
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Yes, I'm happy with that.

Got the oil port plug out, and fitted my 5 bar sender with adaptor

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fits snugly alongside the block, without interference for thew oil t/stat housing

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Now I'm thinking I should look at having the flywheel drilled for a pulse wheel.

I should be able to mount a sensor here...

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Or, cut the bell housing & weld it here (where my finger is touching the casing), above the timing window...

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