Engine rebuild help - opinions needed!

mj2k
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Re: Engine rebuild help - opinions needed!

Post by mj2k »

KevJTD wrote:****it's a budget build*****

:lol:

soon changes when shiny bits become tempting :D

cracking thread still 8-)
It was more the price (less than a set of std pistons) and potential rarity which attracted me; they're being safely tucked away for 'version 2', which may involve turbos. No 2 on my bucket list is creating a reliable twin turbo Busso :D

Plan is, once I've proved I can build an engine which doesn't end up needing to be collected in a large dustpan and brush, is to build a 3.0 12v with 2.5 crank (to give a low compression 2.8 - the forged high compression pistons will make sure it's not too low), twin turbos (opportunity is knocking for that too ;)), a 164 plenum, Sud pressure regulator, a programmable 3rd party ecu and sensors / intercooler pinched from a Subaru twinturbo to create something both more powerful and more reliable than the 2.0TB.

Kegsti66
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Re: Engine rebuild help - opinions needed!

Post by Kegsti66 »

Sounds a great project. Wish I had the know how.
Reminds me of these.


https://www.hemmings.com/blog/article/p ... win-turbo/


Good luck and keep us posted please. 8-)

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KevJTD
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Re: Engine rebuild help - opinions needed!

Post by KevJTD »

mj2k wrote:
KevJTD wrote:****it's a budget build*****

:lol:

soon changes when shiny bits become tempting :D

cracking thread still 8-)
It was more the price (less than a set of std pistons) and potential rarity which attracted me; they're being safely tucked away for 'version 2', which may involve turbos. No 2 on my bucket list is creating a reliable twin turbo Busso :D

Plan is, once I've proved I can build an engine which doesn't end up needing to be collected in a large dustpan and brush, is to build a 3.0 12v with 2.5 crank (to give a low compression 2.8 - the forged high compression pistons will make sure it's not too low), twin turbos (opportunity is knocking for that too ;)), a 164 plenum, Sud pressure regulator, a programmable 3rd party ecu and sensors / intercooler pinched from a Subaru twinturbo to create something both more powerful and more reliable than the 2.0TB.
That's definitely not a budget build and one to look forward to 8-)

sure the stage 1 will go well, great that you can resist going straight to stage 2 though!
Giulietta JTD 170
Lancia Delta integrale
Lancia Flavia coupe 1.8 1963
Lancia Dedra turbo
Renault Clio 197 RS

I'm bad with people things
But I should have tried more

mj2k
Posts: 112
Joined: Mon Feb 18, 2019 10:46 pm
Location: Herts

Re: Engine rebuild help - opinions needed!

Post by mj2k »

Kegsti66 wrote:Sounds a great project. Wish I had the know how.
Reminds me of these.


https://www.hemmings.com/blog/article/p ... win-turbo/


Good luck and keep us posted please. 8-)
Wow, that is pretty similar to what I've got planned :D Love the way they've used a giant custom intercooler to replace the plenum, I might have to pinch that idea if it's possible to get a twinport intercooler in that size without spending a fortune.

Don't think I'm likely to get quite that sort of finish though, the whole package is quite spectacular.

And thanks @KevJTD - the temptation is enormous but I'm resisting so far...

mj2k
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Re: Engine rebuild help - opinions needed!

Post by mj2k »

Turns out the cavitation holes I was worried about are present on the nearly-new 24v block too. Judging by the way the tiny bit of water I put in the holes doesn't go anywhere it appears the holes don't do anything, so they must just be from when the block was cast:

Image

mj2k
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Re: Engine rebuild help - opinions needed!

Post by mj2k »

That's it, bottom end done at last!

Image
Image

Since I couldn't find an Alfa 75 flywheel anywhere it's ended up being a low compression (approx 8.0:1) 2.8 using the 3.0 block / liners and crankshaft / flywheel from a 2.5 gtv6.

I was planning to use the lovely forged high compression pistons I got (plus new lightweight rods) to make a turbocharged engine eventually, but realized:
  • The 2.5 crankshaft isn't nitrided so will get damaged more easily
  • Putting 300ish BHP through a chassis designed for a max of 168 (in the turbodelta) would be a bit silly
  • It should still make all the correct Busso noises but I won't have to worry so much about using strenghtened transmission components or blowing the standard transaxle to smithereens
  • It should work fine with the standard 75-type l-jetronic ignition / injection system which I have in full, which will save me having to spend another age searching for bits to complete the partial 164 motronic system I've got
So now, at last, I can move onto doing the heads and then transaxle :)

All of which means I've got a big list of excess bits which I won't be using:

https://www.ebay.co.uk/itm/293222519210gtv6 2.5 short block
https://www.ebay.co.uk/itm/293203391840Alfa 164 loom - untested but all appears to be intact
https://www.ebay.co.uk/itm/293203391854Alfa 164 Motronic ecu - type 0 261 200 11. Untested but contacts look good
https://www.ebay.co.uk/itm/29322697377275 / gtv6 inlet trumpets and injectors - not tested, assume the injectors will need a clean!
https://www.ebay.co.uk/itm/29322740877075 / gtv6 2.5 12v cylinder heads - appear to be in great condition. I've kept the oil pump drive and camshaft sprockets but could stick an old, rusty set on if you need them
https://www.ebay.co.uk/itm/29323205736675 / 164 3.0 12v crankshaft - seems to be in pretty good condition from my measurements
https://www.ebay.co.uk/itm/293232058248156, etc 2.5 24v crankshaft - appears almost unused
https://www.ebay.co.uk/itm/293203391795164 3.0 12v inlets plus Motronic injectors Not used in ages so will definitely need a clean!
https://www.ebay.co.uk/itm/293226967731164 3.0 12v 'distributor' plus cover, cap and rotor Rotor arm isn't the best, but the rest is in good condition
https://www.ebay.co.uk/itm/293203391775164 3.0 12v 'distributor' Not the greatest, but it turns ok
https://www.ebay.co.uk/itm/293226967147164 3.0 12v 'distributor' Not the greatest, but it turns ok
https://www.ebay.co.uk/itm/293227391116those lovely Wossner forged pistons - brand new and unopened
https://www.ebay.co.uk/itm/293203391794916 gtv, etc 24v rocker covers - good condition
https://www.ebay.co.uk/itm/293227404086116 gtv6, etc 12v rocker covers - good condition
https://www.ebay.co.uk/itm/29323102534675 / gtv6 Busso sump - good condition, but will need gaskets. Just what you need for a fwd to rwd Busso conversion, along with:
https://www.ebay.co.uk/itm/293226757655Alfa 75 / gtv6 oil pump - Some scoring on rotor and can't claim it's perfect / unused, but it's within tolerances, and at least you know what you'd be getting
https://www.ebay.co.uk/itm/293226762861Alfa 164 12v oil pump - Some scoring on rotor and can't claim it's perfect / unused, but it's within tolerances, and at least you know what you'd be getting
https://www.ebay.co.uk/itm/293226766950Alfa 164 12v oil pump with pickup - This one's in surprisingly good condition
https://www.ebay.co.uk/itm/293226767995Random 75 / gtv6 / 164 12v oil pump bits - Rescued from the bottom of a parts box, may come in useful to someone
https://www.ebay.co.uk/itm/29322678588075 / gtv6 / 164 12v main bearing caps - Another rescue from the parts box. Seem to be in pretty good condition

mj2k
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Re: Engine rebuild help - opinions needed!

Post by mj2k »

Underneath all the muck the heads aren't in bad condition - no signs of damage to the seats and I can't detect any wear in the guides yet, so this must have been one heck of a nice engine before it was laid up. However there is some cavitation on the underside of the heads where corrosion had been eating away at it, and the exhaust valves are all pitted by rust on their top sides; the exhaust manifolds weren't fitted so they were the most exposed to the elements.

So there's a moral in here - make good use of your best assets before old age takes it's toll :D

Still, as I was looking through the valve seats to the inlet / exhaust ports I realized just what a beautifully engineered thing the Busso is - the paths are almost dead straight! Probably goes some way to explaining the lovely noise they make.

Before:

Image

After:

Image
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Typical valve seat:

Image

Impressive sight:

Image
Image

mj2k
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Re: Engine rebuild help - opinions needed!

Post by mj2k »

Head number 1 (for pistons 1-3, and with the oil pump drive) is much more pitted and rotted than the other head (you can see the state of it in the bottom left of this pic):

Image

It's just about useable since the pitting doesn't extend into the ring where the liner meets the had gasket, but it's still pretty bad, and all the exhaust valves are rust-pitted too. Skimming wouldn't work because the pitting's so deep, so it'd be sensible to try and find a new head, or heads :(

The 2.5 heads won't fit (well, they would, but it'd do weird things to the compression and the valves are smaller so airflow would be affected), so looks like I'm now on the lookout for a new pair of heads (preferably with valves). Anyone got a 3.0 12v head or heads they fancy selling off reasonably cheaply?

alfadave
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Re: Engine rebuild help - opinions needed!

Post by alfadave »

Have you tried GTVince on the AROC website, under parts for sale.

He's in the Birminham area

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LooLooSud33Spider
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Re: Engine rebuild help - opinions needed!

Post by LooLooSud33Spider »

I’ve got a pair of 3.0 12v heads
Alfasud Ti 1984
Alfa Spider 2.0 Ts 916
Alfa Spider 20v Turbo

mj2k
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Re: Engine rebuild help - opinions needed!

Post by mj2k »

alfadave wrote:Have you tried GTVince on the AROC website, under parts for sale.

He's in the Birminham area
AFAIK GTVince is now officially dead as a parts supplier - the various complaining threads about him over the years (especially one infamous one about a court case) have done for him as far as I can tell; he was doing a 'parts clearout' back in March where he was selling the last of his Alfa stock, and though we exchanged one email / text he has completely stopped replying. I opened a thread about it on alfaowner, but he appears to have completely disappeared from everyone's radar now, so I presume he has given up on Alfa parts altogether.

mj2k
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Re: Engine rebuild help - opinions needed!

Post by mj2k »

LooLooSud33Spider wrote:I’ve got a pair of 3.0 12v heads
Thanks Lou, look forward to the pics :)

alfadave
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Re: Engine rebuild help - opinions needed!

Post by alfadave »

Actually, looking closer on the AROC website, some of the parts ads are well out of date, including GTVince

mj2k
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Re: Engine rebuild help - opinions needed!

Post by mj2k »

Ok, some more opinions needed please :D

Just got a brand new set of Alfa rods delivered for my 2.8 12v Busso ongoing project (no car for it yet of course!) so I couldn't resist unwrapping one of the Wossner pistons just to see how it looked on a brand new rod:

Mmm, nice!
Image

You can easily see how they increase the compression, look at the height of the crown compared with standard!
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One fly in the ointment:
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Hmmm, the last one could be an issue. The old 'handed' rods had a drilling in the top presumably to spray oil onto the inside of the bores as it was running. The new rods don't have that drilling, and since the 12v doesn't have a separate oil spray at the bottom of the liner like the newer Busso, I'm wondering if it is a vital part of the design despite being an obvious stress raiser.

Old 12v Block
Image

Newer 24v Block with oil sprays
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I really, really want to use the new rods if I go down the Wossner route, but if I do could I be condemning myself to very rapid bore wear and probable engine seizure? Or will it be fine?

I get the feeling I know the answer already since there are no 'flinger' grooves cut into the big ends so I might have to stick to the old rods, but are there any other alternatives like 3rd party oil spray bars or suchlike?

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