2L teardown measurements and questions

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TulsaSpider
Posts: 1547
Joined: Tue Apr 29, 2008 7:33 pm
Your car is a: 1978 Spyder 124 2L
Location: Tulsa, Ok

2L teardown measurements and questions

Post by TulsaSpider »

Crank journals measured as follows:

1 52.75
2 50.79
3 52.84
4 50.62
5 52.88
6 50.58
7 53.06
8 52.77
There has been some talk about rear seal leak causing a groove? I didn't see/feel any groove on the rearmost journal so I guess that is good. I see a slight discoloration on the main journals, bit of a brownish stripe in the middle. So does this crank need any attention at all I am wondering?
Image

Image

Bore measurements MM in the top. No discernible ridge
1 83.91
2 83.92
3 83.84
4 83.90
I am planning to get some domed pistons. I read the other day where Mark said that the pistons should go to the machine shop for proper fit.

Oh and there was one thing that kinda looked iffy. There seems to be some damage on the tail end of the aux shaft. Is this in need of replacement?
couldn't get my camera to take a really good pic.
Image


Image


Image
1978 Spyder 1800 make that 2L! Finally making real progress!
User avatar
TulsaSpider
Posts: 1547
Joined: Tue Apr 29, 2008 7:33 pm
Your car is a: 1978 Spyder 124 2L
Location: Tulsa, Ok

Re: 2L teardown measurements and questions

Post by TulsaSpider »

nobody?? bump!
1978 Spyder 1800 make that 2L! Finally making real progress!
User avatar
TulsaSpider
Posts: 1547
Joined: Tue Apr 29, 2008 7:33 pm
Your car is a: 1978 Spyder 124 2L
Location: Tulsa, Ok

Re: 2L teardown measurements and questions

Post by TulsaSpider »

double bump bump!
1978 Spyder 1800 make that 2L! Finally making real progress!
User avatar
TulsaSpider
Posts: 1547
Joined: Tue Apr 29, 2008 7:33 pm
Your car is a: 1978 Spyder 124 2L
Location: Tulsa, Ok

Re: 2L teardown measurements and questions

Post by TulsaSpider »

Suggestions? anyone?
1978 Spyder 1800 make that 2L! Finally making real progress!
ventura ace

Re: 2L teardown measurements and questions

Post by ventura ace »

TulsaSpider wrote:Crank journals measured as follows:

1 52.75
2 50.79
3 52.84
4 50.62
5 52.88
6 50.58
7 53.06
8 52.77
There has been some talk about rear seal leak causing a groove? I didn't see/feel any groove on the rearmost journal so I guess that is good. I see a slight discoloration on the main journals, bit of a brownish stripe in the middle. So does this crank need any attention at all I am wondering?


Bore measurements MM in the top. No discernible ridge
1 83.91
2 83.92
3 83.84
4 83.90
I am planning to get some domed pistons. I read the other day where Mark said that the pistons should go to the machine shop for proper fit.

Oh and there was one thing that kinda looked iffy. There seems to be some damage on the tail end of the aux shaft. Is this in need of replacement?
couldn't get my camera to take a really good pic.

My workshop manual says 52.985 - 53.005 for the main bearing journals, and 50.792 - 50.802 for the crankpin journals. Your mearsurements show quite a bit of variation from this (what is the 4th crankpin journal measurement?). I would polish the journals smooth with some fine emory cloth and attempt a more accurate measurement.

Your bore diameters seem to be standard size. I would have a machinist measure the bores for roundness, and make a recommendation for staying with standard bore or going oversize. You should definitely let a machine shop set you up for proper fit of the pistons and all the bearings.

The pictures of the aux shaft are a little blurry, so hard to say. Are you using a mechanical fuel pump, and are those wear marks from the fuel pump? If so, I'd just clean it up and continue. If you aren't using a mechanical fuel pump, I wouldn't be concerned in the least, since the part of the shaft doesn't touch anything (except the fuel pump, or the connecting rods if your engine timing is not set correctly!).

Alvon
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TulsaSpider
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Joined: Tue Apr 29, 2008 7:33 pm
Your car is a: 1978 Spyder 124 2L
Location: Tulsa, Ok

Re: 2L teardown measurements and questions

Post by TulsaSpider »

Thanks Alvon. I will re measure but I was pretty careful. Maybe it has had work before. The damage is to the end of the aux shaft, it's like a gash, and yes the pics are blurry, best I could do. I am wondering is this from a previous time when the timing belt may have broken? I don't know the history of this motor. I did start it once for about 2 min. before I removed it from the car. Thanks for the reply!
Clark
1978 Spyder 1800 make that 2L! Finally making real progress!
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TulsaSpider
Posts: 1547
Joined: Tue Apr 29, 2008 7:33 pm
Your car is a: 1978 Spyder 124 2L
Location: Tulsa, Ok

Re: 2L teardown measurements and questions

Post by TulsaSpider »

OK I had a chance to go re-measure everything while I am not super tired and sweaty! I have a digital micrometer so I thought I would take both high and low measurements. I see there is some variation here so I am guessing I need to get it cleaned up

LOW HIGH
FRONT
1 52.70 53.23 Main
2 50.77 50.88 rod
3 52.86 52.97 main
4 50.50 50.74 rod
5 52.78 53.10 main
6 50.50 50.57 rod
7 52.97 52.86 main
8 50.50 50.55 rod
9 52.68 52.84 main
REAR
1978 Spyder 1800 make that 2L! Finally making real progress!
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