My Engine Build

[Yumann]

That's "You're".

Just updated my "210/225 Differences" sticky and I'm reminded that someone posted the part numbers for the pistons and conrods being the same on the AMK and BAM, so that now suggested that they DO all have 20mm pins. Confused.

Anyway, we're cluttering up Yumann's thread.

Picking up the head today? Busy weekend then

Yes Phil its an AMK, the bam rods and pistons are exactly the same as It clearly states that in the mahle catalogue. You confused

Picked up the head yesterday, and was not best pleased when its a week late and hes just started building it when I arrive. To add to all that hes constanly talking, showing me **** like arp bolts and doing experiments with torque wrenches and angle tighting them to see which one was tighter.

Anyway I starting to get a bit annoyed now and say you mind getting on with the head as I have work, reason for time wasting he does not have the tensioner there and is waiting on another head

As for the porting and polishing its better than it was but I believe I could of done a better job myself.

On the plus side I did see him assemble the head and made sure all the valve springs where properly seated, and also made sure he did the timing properly.

Its all go now starting tomrrow.

 

[Yumann]

Update first build pics:

 

[Yumann]

 

[Yumann]

Porting redone

 

[Yumann]

 

[DPJ]

The guy seems to have come up with the good in the end.

 

[ibizacupra]

what grit finish is the intake and exhaust?
cant make out from pictures..

 

[Yumann]

Not sure bout Exhaust is more than 120 by the looks and intake is done with a burr.

 

[ibizacupra]

not tidied up at all with some thing more even.finer on intake? (not polished, but a more even patina) - something like the exhaust ones look like.

thats how mine is.
exhaust was more polished than intake, which looked like your exhaust ports do not, certainly not as run from the burr alone.

 

[Yumann]

From what I have read all intakes should be polished with 80 grit and exhaust 120 or above. The pictures are deceptive as the intake doesnt look as rough as that iirc.

Using rotary stones on a ally head is a pain as it keeps clogging.

Anyway It cant be worse than std.

 

[HTC]

Compare to:

 

[ibizacupra]

intakes are well shiney/smooth

too smooth?

this was a largeport head to begin with yea?

 

[Yumann]

Yeah that just looks to smooth for my liking on the intake, and the valve channels also look to sharp and narrow.

 

[Mitchy]

Good pictures and project mate

Glad you clarified the AMK/BAM engines having 20mm pins Im almost positive it was jabbasport that started this 20mm vs 19mm bollocks!

Ive always read in the past, the standard pistons being good for 500bhp, rods 350bhp. Im now wondering if this 350bhp rod limit was based on earlier 1.8T engines that had the smaller 19mm pins? I wonder Ive only ever heard of ibizas/octavias and golfs spitting rods, not heard of AMK/BAM failures due to power being too high. Or did the earlier engines also have the 20mm pins?

Ive been running mine extremely close to this limit and probably even beyond for over 2 yrs now and still without failure. Everyone told me thay would snap with 350+bhp/350+lbft but yet they are still going strong.

So when you upgrade the rods, what aspect of the rod are you actually improving? If the pins are same size, is it just the tensile strength of the standard rods that are questioned and then changed.

Keep up the good work Yumann, like informative learning threads like these

 

[ibizacupra]

Yeah that just looks to smooth for my liking on the intake, and the valve channels also look to sharp and narrow.

channels look good to me, surface finish would be my only comment.

 

[ibizacupra]

Good pictures and project mate

Glad you clarified the AMK/BAM engines having 20mm pins Im almost positive it was jabbasport that started this 20mm vs 19mm bollocks!

Ive always read in the past, the standard pistons being good for 500bhp, rods 350bhp. Im now wondering if this 350bhp rod limit was based on earlier 1.8T engines that had the smaller 19mm pins? I wonder Ive only ever heard of ibizas/octavias and golfs spitting rods, not heard of AMK/BAM failures due to power being too high. Or did the earlier engines also have the 20mm pins?

Ive been running mine extremely close to this limit and probably even beyond for over 2 yrs now and still without failure. Everyone told me thay would snap with 350+bhp/350+lbft but yet they are still going strong.

So when you upgrade the rods, what aspect of the rod are you actually improving? If the pins are same size, is it just the tensile strength of the standard rods that are questioned and then changed.

Keep up the good work Yumann, like informative learning threads like these

ibiza's have 20mm pins... dont spit rods.
LCR's have done tho far more frequently.

 

[Yumann]

channels look good to me, surface finish would be my only comment.

From what I have been told from my neighbour engineer is that it should be more wing tips eg wider V than narrow v something to do with the optimium angle of fluid dynamics.

I think we're looking to deeply at it I am sure it is well better than std anyway.

 

[Yumann]

A rod wont just break unless there is a major flaw, more than likely fatigue over a period of time then break, that could take ages.

 

[ibizacupra]

poor mapping, excessive cylinder pressures = bang also... not just boost.

some "early days remapped" LCR's went pop as I recall.

 

[Ruddmeister]

Rods also broke on 'some' LCR's due to revving past the limiter

(The result of some over zealous downshifting mainly)