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Hi - Im somewhat new here. Here's my intro post:

http://www.alfabb.com/bb/forums/guests-new-members-introductions-please-read/347730-hi-berlin.html

Im looking for some advice:

Im about to take delivery of a 2.0 TS engine which had been built up for use with a turbo in a 105 GTV. The seller changed his mind about it and sold it to concentrate on his 101 Giulietta Spider project. I got it for a price which wasn't much more than what donor TS engines cost here in Germany so Im taking a risk with what he claims has been done to it. I wont get any receipts. Only the sellers word for it.....

Its never been started, but has apparently new timing chain, seals, bearings, pistons, liners and valves, All standard, allegedly. The head has been ported, which I can see in the photos and the valve seats ground/modified somewhat. Hopefully the right way.... The photos show a new timing chain, and the drilled crank with spiggot bush. All apparently carried out by a reputable Alfa garage..... in Greece. It wasnt JimK, but hopefully by someone who has at least read the book! There is a decompression plate fitted to work with the turbo, and the standard cams have been reground to a turbo suitable profile.

So I want to fit this to my S2 Spider, without turbo. I will document progress here, although for now Im hoping for some advice on what I should do to ensure success. What can I check to make sure everything is as claimed? here is my plan:


  • Measure static compression to see if rings are working. Measure CR using oil and syringe method.
Head:
    • Remove/discard decompression plate, and based on above CR measurement get head shaved to achieve 10:7:1 or so. (anyone need a Decompression plate?)
    • dump cams and buy something appropriate. RJR, Alfaholics, or ??
    • check cam followers, valve stem seals and seats as per shop manual.
    • I am tempted to let the Head Shop check the valves, followers, stem seals etc when they shave the head surface, and then have them install the cams and set the valve clearances. I dont have a shim set. thoughts? am I being lazy?
Bottom End:
    • check bore-piston / ring clearances. It should be clear if pistons are new, and hopefully what type they are.
    • Should I remove the pistons and rods? I could then check the rings properly, but if the compression is ok, and the clearances also, is that enough?
    • check main bearing clearances. is the cap gap check enough or should I disassemble and use plastiguage etc?
    • check crank axial play.
    • crank run out? can this be done in situ?
    • spiggot bush diameter check
Anything else?

If there is anything else anyone can think of , your advice is much appreciated. I would rather not pull the whole thing down and start again but if everyone thinks its the best way, then I guess I will.

Ive assembled heads, front ends, timed cams etc before, but never built a up a crank and pistons. With the shop manual and the usual books, and a little advice, I hope everything comes together.

Otherwise, I plan to stick with my 40DCOEs and single plug 123 Distributor. There is a single plug TS engine on the Alfaholics website that seems to be ok, so Im going to try this approach for now as to use the parts from my existing Nord engine. One can always upgrade later. Plus it might make things simpler when I go to get my German TUV approval

Please let me know what you think. all input much appreciated!
thanks, andrew
 

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stick with F.I. carbs are just a controlled fuel leak.. and FI is much easyer to adjust... fact.. even it you get all the carb jets emulsion tubes, etc perfect at sea level,, once you go up 500 meters all is lost.. at higher elv. even worse FI will work perfectly at all elv. I don't know why people want to go back to carbs.. at all.. back in the 50's-60's everyone wanted a ' fuely ' car. now carbs, come on..
 

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Discussion Starter #3
yes, I completely agree as to the benefits although there is something nostalgic about that controlled fuel leak..... anyway, in Germany, you need to keep a certain level of originality to receive "historical" registration. EFI or any other tech not available within 10 years of the vehicle build date would mean 2-3 times higher annual road tax and semi-annual emissions checks which would be hard to pass. so not really an option unless I reverse engineered a 105 SPICA system, which I suppose might be a possible, but nevertheless bizarre solution....
 

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If it's got stock pistons in it, instead of shaving the head to get the compression up you can fit a set of earlier 1750/1800/2l non twin spark rods - they're 1mm longer and will bump the compression up to around where you want it to be without skimming the head. This is fairly common practice among the TS guys down here.
 

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Discussion Starter #5
thanks for the tip re: Nord Rods. Im thinking that Im going to strip the crank anyway, and replacing the rods while Im there would make sense. I skimmed through the forum and read that the pistons on Nord rods will protroud .25mm and therefore need chamfering. Is this a DIY job or one for the shop? and I suppose the valve reliefs need deepening by 1mm?
while I see the elegance in the solution, is it really cheaper/easier than shaving the head?
 

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Discussion Starter #6
If it's got stock pistons in it, instead of shaving the head to get the compression up you can fit a set of earlier 1750/1800/2l non twin spark rods - they're 1mm longer and will bump the compression up to around where you want it to be without skimming the head. This is fairly common practice among the TS guys down here.
Hey Mr Nera - Ive got some Nord rods and going to fit on the weekend as you suggest. Once again, are they a straight fit? Ive read lots about valve pockets, chamferring etc, but then others on the forum saying they just bolted them up.

Also, what cams are people using with this Stock TS Piston / Nord Rod combination? eg anyone know what lift is possible without piston pockets?

thanks!
 

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Discussion Starter #7
a bit of an update:
the engine is apart and seems to be in good order. A dead bee made its way from greece in number one cylinder!

the cylinder liners are super clean but have some vertical marking. see photo. its not possible to feel a scratch or groove. The marks are present on all of the liners and I dont think I caused them when removing the pistons and rods. does it look normal? or should I get it honed?

the piston to bore clearance is very tight. with the piston upsidedown, measuring between the bolt holes, I get less than 0.008in where as per the manual I see the tolerance is meant to be 0.016 - 0.023in. I measured both pistons 1 & 2 with the same result. the seem to slide fine in the bores, also with the rings (which incidenctly have gap clearances at the very top of the tolerance band) Should I be worried about this? another reason for a hone? or am I doing something wrong? It seems a strange problem to have.....

The AE/Borgo pistons seemOK, but a little scuffed on the top, and one of them is 4g heavier than the others. It also seems cleaner than the others, like it was replaced or comes from another set. Im hoping to get that sorted out and the conrod small end bearings pressed in this week.

thanks for your hints!
 

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Are you sure you are not getting your units mixed up?

.008" is too much clearance. However, .16 - .23 mm translates to .004" - .006" clearance which is better.

The bores have not been honed correctly: there is not cross hatching... the rings will NOT bed in correctly. This should be done with flex hone (30 degrees to the horizontal).

I think the liners have not been out of the block by the look of things. This says to me that the engine preparation was not performed by anyone familiar with Alfa (or was done on the cheap).

I would have the bores honed properly, and then reassess the scores....

Why are you having the con rod small end bushes pressed out? they are very robust and rarely need doing.....
 

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Discussion Starter #9
thanks for your comments... and also regarding your car/other post

the engine was built buy an alfa mechanic, and its all very clean, with new timing chain, rings, bearings, and by the looks of it, cam followers. Those things I can confirm, but otherwise, it was probably done on the cheap and hence the odd piston weight.

Small End bearings: I just thought I would switch everything while I was there. youre right though, the bearings in both my old (TS) and new (nord) rods look fine, and I did wonder why I was bothering. Ive got them now so may as well go ahead.

Cylinder Honing: yes, i might do this. Ive had this done before on iron block engines but people seem to be more about replacing liners on alfa engines from what Ive read. thanks for the hint

dimensions: could be! I have an ancient feeler gauge that once belonged to my grandfather. I just assumed the numbers referred to thousands of an inch, but I will try to callibrate it against my vernier /dial indicator / something else. or just buy a new one.

did you replace the rod bolts? I think Im going with new, standard bolts. ARP is overkill for me I think....

cheers!
andy
 

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I only replace bolts with non stadard, high rev engines. And then with ARPs.

Check clearance in the top ring grooves. Must be < .0015".
 

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an update on my little project here:

my local machine shop confirmed the scoring/marks in the bores were no good and that the liners needed boring or replacing. after looking at the options for new piston/liner sets, probable requirement for valve relief cuts and what I spent on the Nord Rods, Ive jumped in and gone for +0.5mm, 11.5 CR JE Pistons from Paul Spruell. Still waiting for them to pass German customs and then can get the old liners bored to suit. Will then revert to the TS rods. If the CR turns out to be too high, then I have the 1mm decompression plate from the PO.

The machine shop also reckons the small end bearings in the rods are out of round, so just as well Ive got replacements. But what I hadn’t noticed was the deterioration of the crank bearing surface. See photo, plus there is also pitting which isn’t so clear in the photo. The regrind and nitride costs from the machine shop were astronomical, so thanks to hunttheshunt for the recommendation of another specialist which sells complete remanufactured cranks for a reasonable price. So the crank and bearings are in, and hopefully the pistons will show up next week.

Otherwise, everything is prepared for the old engine to come out tomorrow. Ive booked the car in to have the engine bay painted and a few rust spots repaired next week. However I don’t really want to pull out all wiring, plumbing, steering box etc. Has anyone managed to mask off this stuff and paint around it?
 

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Old engine is out. Remaining engine bay parts are masked as best as possible as per Robertsmania"s suggestion and its off to the paint shop.

Now to turn my attention to the engine. I have a somewhat unknown regrind of the 6051 3306/7 cams with Variator. The Exhaust valve clearances are all within spec although the intakes are as follows:

1. 0.008"
2. 0.009
3. 0.009
4. 0.010


Once again, this thing was allegedly rebuilt by a professional and the above clearances seem deliberately set. I understand some cams run tighter clearances than the standard spec - any as tight as the above? Would it be reasonable to leave them as is? or should I disassemble and adjust to the normal 0.015 - 0.018?

thanks for your help!
 

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Its been a long time since I updated this post, from the above point, and following slow shipping and customs clearance, I received my shiny new pistons in Jan

I got them home and to my horror, they were the standard 84mm rather than the oversize 84.5 I had ordered to match my still-to-bored liners. Switching them out was fine, but shipping time and cost to the US is high, and it was a total nightmare trying to get my import tax refunded. In the end I gave up and ordered new 84mm liners locally to suit the pistons and Paul Spruell fixed me up for the difference.

The liners arrived and on test fitment /measurement tuned out to be 84.2mm and out of spec. They went back, another week was lost, and replaced with, finally, the right parts.



I balanced everything as best as possible for a home mechanic and fitted everything together. Too my horror I found the hairline mark in one of the pistons. It caught my fingernail and appeared to have propagated like a crack. JE Pistons and Spruell assured me that pistons don’t crack like this, but I was welcome to send it back to the US for examination. Ahhh!

I took it to my local machine shop who polished the end of the mark out, confirming it was only superficial and nothing to worry about. At least this one was a false alarm

Following my JimK book, I went to torque the head to 100Nm to find the middle nut wouldn’t tighten. I got to about 50Nm, turned and turned, then undid to investigate. The stud came out with the nut, and thread all together. The threads were cleaned and oiled so I guess its yet another gremlin in an old engine of untrusted origin. So I pullued it down again, had the machine shop install a "Re-coil", and off I went again.

Im learning lots and despite one setback after another, am generally enjoying things, But above all, Im finding this old engine caper more a test of patience and perseverance than mechanical knowledge….
 

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