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Discussion Starter #1 (Edited)
My Z20LET Rebuild. 400+bhp expected! Update pg3

Easy people.

Ok so quick background if you dont know of me. I have a Mk4 Astra GSi. Owned it for some time now, well over a year and im wanting more power then my 233.0bhp/305.3ft-lb. I decided it was finally time to build the engine id always talked about!

First things first, we need to see the spec list of what it should be at the finish line in around 6-8months time. Im giving my self abit of time doing this as i am soon to goto Nurburg and travel europe so cant afford to splash out on all components yet.

Provisional spec list:

Z20LET
Accralite/Forged Pistons
Arrow Precision conrods
Nortech equal length manifold
Garrett GT30... Not decided which yet
Siemens Deka Injectors

Tial external wastegate
Tial BOV / Turbosmart BOV (Unsure which)
Management (Pending)


So, Wednesday 2nd September was a good day for me all in all, 2hour drive to wales an 2 back obviously. Funniest part of the trip hmmm, getting to the M6 toll plaza and it wanting £3.70 off me, i only had £3.60 in change, but around £400 in £20 notes in my pocket haha. Had to use the "Call Assistance" button :(

You think, why to wales. Well when you can pickup a Z20LET for £70 you go, originally i was going to pay £60 but i wanted the rocker cover so was extra £10. An here are my winnings.






Now you thinking, how the hell could i get what i did for such a cheap price. Reason being are a few hah, first is what you see is what i got! However keep reading i think we may discover something (I say we, i already knew....)

Right, anyways the images above when its not in my boot i took on Thursday 3rd September when i lifted it out (They arnt as heavy as youd expect). Stripping it down began to discover how bad, or good it was.

All parts from the head:


Down to the block, an things get interesting.






Hey, did anyone fancy a game of spot-the-difference?



So, yea.... Melted number 3 as per usual




An work was finished on Thursday.

Friday 4th September.

Block came out my unit again and... more progress was made.




At the point of getting the crank out, and cleaning the block it was time for a break... So i went to a local shop i know who can do wonders with engines and left the block there to have it hone'd an hopefully get the buildup of piston removed. If the honing fails, its 1 of 2 options in my mind, bore out and have a hybrid Z21LET haha, or bore out and get all cyclinders steel lined.

After i got back i decided to start about cleaning the components.





For all my cleaning on everything you see above and further on in this log i use Cellulose Thinners. Works wonders and as you can see from the pics.

Next update expected Monday 7th/Tuesday 8th.
 

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wel good luck with that but not the sign of a good engine is oil ******* out out
 

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A.O.N - Club Member (Dave)
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Resize pics needed badly! Apart from that im looking forward to the build
 

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Discussion Starter #8
wel good luck with that but not the sign of a good engine is oil ******* out out
Im not following you? Theres no oil in it, and its hardly a engine anymore the blocks gone to be for honing.
Resize pics needed badly! Apart from that im looking forward to the build
Sorry there will be no rezizing. Unfortunatly this forum isnt blessed with the pluggin some otherss are were it automatically resizes images.
 

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I wish I had half of your mechanical knowledge mate! impressive though, will look forward to seeing this develop.
 

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Im not following you? Theres no oil in it, and its hardly a engine anymore the blocks gone to be for honing.
picture 2 m8
 

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Sorry there will be no rezizing. Unfortunatly this forum isnt blessed with the pluggin some otherss are were it automatically resizes images.
when using photobucket you can reduce the size of them by clicking edit and then resize.
 

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Discussion Starter #12
I wish I had half of your mechanical knowledge mate! impressive though, will look forward to seeing this develop.
I am self learnt mate, not been to college or anything.
picture 2 m8
Yea...? Left over oil in the block from when i drained it. As you can see its coming out the oil line that feeds the turbo!
when using photobucket you can reduce the size of them by clicking edit and then resize.
I know, i dont intend to do this, sorry.
 

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Sounds a bit like my spec that :lol:

And no worries for giving you some info i dont mind :)

I used alot of brake cleaner and carb cleaner for cleaning up my LEH engine and bit from my LET engine what i killed :lol:

Quick picture of some proper piston damaged tho :p



Thats what happens at 500+ and the liner lets go for various reasons :lol:

Good look with the build though mate, once you start down the power route though you cant stop :( im thinking of ways to get more from mine now though :lol: fancy over 550 :lol:
 

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Discussion Starter #14 (Edited)
Sounds a bit like my spec that :lol:

And no worries for giving you some info i dont mind :)

I used alot of brake cleaner and carb cleaner for cleaning up my LEH engine and bit from my LET engine what i killed :lol:

Quick picture of some proper piston damaged tho :p



Thats what happens at 500+ and the liner lets go for various reasons :lol:

Good look with the build though mate, once you start down the power route though you cant stop :( im thinking of ways to get more from mine now though :lol: fancy over 550 :lol:
Haha, expect phone calls next il be onto Salty, ahhh whats Jonnys number :lol:

Jonny did you not think of reinforcements in water chamber to prevend cylinder defomation?




Spec is a little like, as i know it works, Im thinking Wossner or Arrow rods... Did your Arror rods survive the blow?

BTW, RS Tuning mapped the GT28, who did the 30?

Cellulose mate, paint it on and jetwash off :cool:

Anyways got a little update too;

Right then,updates.

Been to get the block and all bores have had a hone, and looking spot on. Would of only cost £20 aswell which was cool. However i know the guys at the shop an got talking regarding what im doing with the block etc.

An hes said forget the cost of the hone, and Ive left the block there...

All bores being Steel lined
Also ordered my mainbearings too.

There wont be a update as such on this log for around a week and couple of days due to me not needing the block back urgently, they wont get the Liners in till Thursday, so i said have it done for the following week.

All in all, bottom end is looking good :D
 

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A.O.N. - Platinum Member
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This thread looks like it could be a really good one,
Good luck with the project matey (Y)

However, The images are a little on the large size and do violate the Forum Rules

14. Posting Images
• Inline images may not be wider than 800 pixels, nor taller than 600 pixels.
• Also remember to not quote posts with images (or be sure to edit out the images!), since this causes excess width as well.
• Images posted in violation of this rule are subject to deletion.
• We offer a Gallery to our Members to host their images in.
• If you choose not to use our gallery, then you must provide your own image hosting. Many members use ImageShack (free) for this.
If you could please resize them in the future it would be apreciated (Y)
 

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Yeah will need to reinforce my block if im wanting to go daft with the boost again. But i doubt i will be. Will just put a bigger turbo on so it will flow more ant less boost :lol:

The rods i had in did survive but didn't re-use them, they wernt the arrow ones there were some i got from the US.

Its been mapped by Gaz @ GR Performance this time. He can't do standard ECU's though. Buy my P8 and loom and he'll be able to map if for you then though ;) :lol: will even come with a map on it :lol:
 

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Discussion Starter #17
Yeah will need to reinforce my block if im wanting to go daft with the boost again. But i doubt i will be. Will just put a bigger turbo on so it will flow more ant less boost :lol:

The rods i had in did survive but didn't re-use them, they wernt the arrow ones there were some i got from the US.

Its been mapped by Gaz @ GR Performance this time. He can't do standard ECU's though. Buy my P8 and loom and he'll be able to map if for you then though ;) :lol: will even come with a map on it :lol:
PM on its way ;)
 

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Love threads like this, look forward to seeing the updates buddy just dont go blowing it up so quickly like jonny did :lol: (Y)
 
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