Problem with the ST FOUND :(

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Every MA series block I have ever measured seems to settle with odd worn bore dimensions. The reasons I say con rods as well is its possible (though unlikely) that they may be different. I don't know the measurements of the fig ones off hand. Sometimes they are shortened to allow for thicker piston crowns.
 
Ok, thanks

i have a bit to go away and think about now and do my own research, will keep you posted ;)

Thanks everyone

Steve
 
oranje said:
these engines have problem with the 3rd cylinder.i have to broken engines with the same prob. 3rd cylinder.maybe factory fault
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If you look at the manifold the 3rd cylinders run is the shortest and the heat/pressure builds up. I melted a piston on that cylinder also. Keep an eye on the igntion timing that probably why it melted mate
 
Hi

I am looking for another bare block with decent bores as then i have two to compare and i would be planning on building another short engine while running the one in the ST. Any help would be appreciated cheers

Steve
 
Steve I have another two, they are similar condition to that one and have similar amounts of wear. (you will find all ST blocks wear the same, at least that's what I have found)

BTW I'm considering having a set of stock rods and oversize pistons made for the ST, if there was enough interest. However such small quantities means they would unfortunately be around £600 for pistons and £750 for rods
 
hummm, right i see what you mean Ed i would be interested in oversized pistons as i was recommended a rebore but i would probably need the rods too for the gudgeon pin size, im really pushing to get the ST running for the summer, i just want it done as it is a waste of money it being sat in the garage and sooner or later me being me will end up using bits to keep the super s going which i really do not want to do, i still need to measure the ring gap on the honed block bores, do you have any idea how much gap there should be maximum Ed? as i obviously dont want any piston slap etc

Cheers

Steve
 
Look at the Ma10 clearances, they will most likely be the same. Pistons can be made in a matter of weeks, rods will take slightly longer.
 
Ed said:
Look at the Ma10 clearances, they will most likely be the same. Pistons can be made in a matter of weeks, rods will take slightly longer.
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Just to completely clarify, i couldnt have a set of oversize pistons that fit the rods in the engine now?

cheers

Steve
 
As I understand it - no. Let me enquire on Monday and I will see if this is still the case.
 
I'd be interested in a set of pistons/rods if you get them made up. Otherwise I will have to organise some custom ones locally.

Steve, you are unlikely to get acceptable clearances from such an old motor with just a hone. I'm sure your machine cost can estimate clearances after a hone by measuring the current cylinder including checking for ovality
 
I would be interested in a set of rods and pistons as i honestly cant see another way around this problem at the moment, What would the issues with piston rings be though too?

Cheers

Steve
 
this sounds ok Frank, although i dont know how the existing liners would come out? i think they are set in with heat or cold? and will they come out so new ones can be put in?, im not trying to deliberately cut corners but trying to get the best option for my budjet

Steve
 
they overbore your block steve, then fit cast iron liners (heat the block and freeze the liner then press them in, or else stepped liners like the rover k series) then they bore the liner to oe spec (or undersize preferably and hone the old piston to suit the undersize)
 
ah, i understand now, similar to how they put tngsten inserts into the dies at work, I will definetly throw this a line.

Cheers

Steve
 
Frank is right thats not a bad idea. Quite possibly the cheapest way to repair the block. Steel liners can be had for around £100 and then the machining works on top. It would be fairly expensive, but cheaper than a set of pistons. This I will also be doing to my ST, along with pistons and rods.
 
I have contacts for liners and can get the machining done here to if you need more help.
 
Right, i have unfortunately sold my Super S, on the forum so all is good, i now have some more space etc to look at the ST properly so should be updating more regular now :)
 
Some Progress...

Hello,

After a long time of iff'ing and arr'ing about bits i thought it was about time to see what work actually needs doing on the ST. so i decided to take the pistons out and check the ring gap on the new block etc.

This is what it was like before i started :D

DSCF5397.jpg


I jacked the car up and secured it with axle stands.

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Then took the sump off and jiggled it free to expose the bottom end :D

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I numbered all the pistons 1 - 4 and arrowed the front facing direction before messing with the big end bolts, undid these and slid the pistons out the top leaving the shells in the correct sides of the big end and put the bolts back in loosely. (The rings on piston 3 where the cracked block is looked fine)

I then tried the top piston ring to check the ring gap on the honed block, the haynes says the top ring should have between 0.2 - 0.3mm ring end gap and across all cylinders i got between 0.4 - 0.5mm which i don't think is good, so i think the engine work i.e. sleeving will definitely need to be done. I am planning of ringing around tomorrow :D

Cheers

Steve
 
about 2" down, i will check again more thoroughly tomorrow down the whole bore and post my results, The shells didn't look too bad either with minimal scoring, you could still see the part number and 'nissan' stamping on them, also the pistons had very little scoring and you could still see the tooling marks where the outside diameter had been turned. So the engine has been looked after with frequent oil changes etc by the looks of it
 
humm, well i will check for absolute definete tomorrow, its just difficult to get the piston rings absolutely parallel in the bore to get an accurate measurement, Block needs taking out of the ST now, not looking forward to that at all :( i just dont want to end up putting it all back together and having piston slap / cylinders not sealing / any other problems :S
 
right had another look at the bores on the blocks today,

The ring gap on all cylinders on the cracked block is between 0.4 - 0.5mm (Top piston ring only)

The Honed block 0.5 - 0.6mm (MA10 states 0.2 - 0.3mm) so the cracked one isn't too far out. I have bought another block off Baz and planning on getting it honed at a different machine shop which seems a lot friendlier and ask a lot more questions about what i am actually doing which is good :)

Just glad everything is slowly moving forward again, I would like to make a new post on the engine rebuild but don't want to make too many posts as there will probably be a few later on along the lines of 'where does this pipe go' :D

Thanks

Steve
 
Glad to see it moving, having seen this car in the flesh its a clean example apart from the engine, should be awesome when done!
 
Ceirwan said:
Glad to see it moving, having seen this car in the flesh its a clean example apart from the engine, should be awesome when done!
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minus an interoir mirror lol

no got that sorted, thats something i am actually confident in doing!
 
Hi

Engine is nearly out and just bought this off ebay (might have been somoene on here? :D)

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i wish i could read japanease! :D
 
Ok so i have now got the engine out, and done my back in so i will be doing as much as possible that does not contain any more heavy lifting. :D

Cant believe how flimsy the flywheel is, just looks like a piece of tin with a ring gear on, glad im replacing the oil seals too as there was some 'oil fling' marks around the flywheel where it looks like the crankshaft seal has been leaking slightly.
 

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