Technical 1368cc pictures (internals) - Engine problem diagnosis

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Technical 1368cc pictures (internals) - Engine problem diagnosis

I removed number one piston ... haven't done the rest yet. No point as the engine is probably fit for the scrap heap anyway :(


Picture tells a thousand words:

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Not a happy bunny :cry:
 
All 4 are cracked!


I checked ePER the other day and i think they were £58 each with rings fitted. So pretty pricy. Think they only come in oversized as well, so will need boring out a little.


I am busy hunting for other piston sources, but now having much luck so far.

Should have bought those forged 72mm ones, that were in the classifieds a few months ago ;)


Kristian
 
I have heard comments the crank isn't up to much over 120bhp, but i bet it could be pushed more, or a bravo 150 tjet crank and pistons could be used. I wonder if the TJET pistons are a direct swap for mine?! THey will be stronger i'd imagine, but don't know if the will fit the rods, or lower the CR at all.


Can any one access the FF ePER? It's not working for me, and i wan't to double check the piston price, and look at the Bravo TJET piston cost.


Drop Aaron a magic PM to ask John about Mahle ;)


He's reading now ;)


Cheers,

Kristian
 
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LOL, just reading, looks tough luck.

Though even thrashing an engine from cold in an engine only 8K old I would not expect that sort of damage in a new engine as its well within manufacturer warranty period and knowing first hand the extremes engine go through for long term durability testing thrashing from cold is a walk in the park.

It could be a contributory factor but maybe when you had a few issues with setting up the MS when running lean maybe some det happened. it can happen very very quickly, and with timing possible being out could have put the pistons under undue stress.

Talk of crank not being any good over 120bhp, can't see why that would be case, who has actually tested it :confused: ours runs 115ish bhp so by that reckoning we are on cusp of breaking it, margins seem far too small to me. I'd like to see pictures of failed crank from a test bed with the dyno print out showing rpm/bhp/torque when it let go.

I am sure I looked up compression ratios of T-jet engines 120/130bhp model 9.5:1, 150/180bhp models 8.5:1, where as the N/A is 10.5 or 11:1 IIRC.

PS diesels typically run something like 16/17:1

Aaron.
 
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Yep, I may have made a cock up on the Megasquirt. Knock to crack 4 pistons would have be heard....but I'm not ruling out it may have been one of the contributing factors. I can't rule anything out, or confirm anything, so it is a possibility, but not too likely imho.


I have seen the 150 tjet as having 9.8...regardless, they are lower CR's but bore and stroke remain the same...so the crank and robs are probably the same, perhaps toughened a bit more.


I'd imagine the CR drop is pistons, and maybe a thicker head gasket like the 1242 kind of thickness (about 1mm thicker).


A lower CR would be to do now, if its not going to cost much more, as I am still silly and thinking of future projects.

Kristian
 
Think we spoke about this before? The bravo 150 TJET is a turbocharged 1368cc superfire. Its the same block, but pistons (possibly crank/rods, and cams) are different. Plus lots of little bits. The bore is the same though :)


Kristian


Yes, you're right. I keep thinking of that as a Deisel. It's probably the engine that's going in the 500 Abarth.
 
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