Lotus Elan

1965 Seven S2

PostPost by: SENC » Sun May 24, 2020 12:56 pm

vstibbard wrote:Suggests either an air leak or leaning out..


Thanks Vaughn, more tweaking today. I have a colortune on the way so I can visualize if I can't sort it.

I'm interested in your thoughts on timing.

timing mark.jpg and


I'd been interpreting the notch between the 2 raised areas as TDC, but may be a good bit over-advanced as a result.

In re-reading the 7 manual, it suggests this mark is 10 degrees BTDC, which would be correct for the 105E and that the notch in the pulley is be advanced a further 1/8 inch for a cosworth 116E. Timing specs in the manual are 105E-10btdc, Cosworth 116E-11btdc, so presumably 1/8" is 1 degree. This suggests to me that with the Cosworth I should be just a smidge outside left of the raised area for static timing (assuming the notch itself is 10btdc). What is your opinion?

IMG_20200524_102518.jpg and


IMG_20200524_102946.jpg and
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PostPost by: SENC » Sun May 24, 2020 4:55 pm

Also have this article on Cosworths for the 7 from and early HLR newsletter. It suggests to retard 1/8" from the timing mark for the Cosworth 116E. I'm wondering if they went the wrong way or based that in the recommended timing for the standard 116E (8btdc)... but either way this would seem to confirm the timing mark on the chest and pulley are set to indicate 10btdc.

IMG_20200524_124257.jpg and
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PostPost by: SENC » Sun May 24, 2020 11:24 pm

Setting the gap to .015/.016" results in a dwell angle around 50 degrees. I know the twin cam in our Elans want a 60 degree dwell angle +/-3% and spec the same gap, so assumed the Cosworth 1500 would be the same and have started tweaking towards 60 degrees. Currently have about a .011/.012" gap and 57 degrees.

If I understand correctly, too little dwell will both keep from achieving optimal spark and increase advance, but it also feels like I'm getting too far from the prescribed gap. Any thoughts/guidance?
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PostPost by: vstibbard » Mon May 25, 2020 6:43 am

I last timed mine about 18 months ago and its pretty much on the timing mark, I can check when I'm up there later this week. A lot has changed since 62, main thing being unleaded fuels radically different and lower octane, my car was used for sprints in UK when new, the heads has been skimmed so slightly higher compression etc and the distributor advance/springs have been played with before my time. The jetting is factory and I've two things on my list, basic AFR check and then a cruise run to make sure on part throttle its not leaning out which will be done as will fitting the bluetooth programable distributor and setting it up.

Right now, it starts on the button with few pumps cold or hot, idles like a modern car, pulls strongly with no noticeable flat spots or pinking.

Could to do me a favour and post a picture of your front suspension, in particular I'm looking to see the routing of the flexible brake line, and its length and fittings if possible.

Cheers

V
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PostPost by: SENC » Mon May 25, 2020 11:25 am

Thanks V. I have this picture on my phone of one of the front brake lines before I replaced them with metal braided from Redline (replaced solely as a precaution since I had the suspension apart). The only difference fitting-wise is the new lines have banjos on the brake end. I'll get some pictures and measurements current state and post later today.

IMG_20200525_072726.jpg and
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PostPost by: alanr » Mon May 25, 2020 12:24 pm

SENC wrote:Setting the gap to .015/.016" results in a dwell angle around 50 degrees. I know the twin cam in our Elans want a 60 degree dwell angle +/-3% and spec the same gap, so assumed the Cosworth 1500 would be the same and have started tweaking towards 60 degrees. Currently have about a .011/.012" gap and 57 degrees.

If I understand correctly, too little dwell will both keep from achieving optimal spark and increase advance, but it also feels like I'm getting too far from the prescribed gap. Any thoughts/guidance?


The correct dwell angle as you suggest should be 57-63 degrees. The mark on the timing cover assuming standard Ford part as per 1500 non-crossflow engine is a 10degrees btdc mark and not a TDC mark.

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PostPost by: joe7 » Mon May 25, 2020 12:46 pm

For the front brake lines I used a steel bulkhead AN adapter, brake line to adapter, jam nut, adapter through body panel connected to 12 inch SS braided dash3 line to AN adapter copper crush washer to caliper. You can take a look at the routing on my 7 at SimpleSevens SB 1756 Joe N.
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PostPost by: SENC » Mon May 25, 2020 1:15 pm

Thanks Alan.

Vaughn, here are a couple pictures of current. I measured the old pipes at 15"/38cm.

IMG_20200525_090918.jpg and


IMG_20200525_090813.jpg and
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PostPost by: alanr » Mon May 25, 2020 2:34 pm

alanr wrote:
SENC wrote:Setting the gap to .015/.016" results in a dwell angle around 50 degrees. I know the twin cam in our Elans want a 60 degree dwell angle +/-3% and spec the same gap, so assumed the Cosworth 1500 would be the same and have started tweaking towards 60 degrees. Currently have about a .011/.012" gap and 57 degrees.

If I understand correctly, too little dwell will both keep from achieving optimal spark and increase advance, but it also feels like I'm getting too far from the prescribed gap. Any thoughts/guidance?


The correct dwell angle as you suggest should be 57-63 degrees. The mark on the timing cover assuming standard Ford part as per 1500 non-crossflow engine is a 10degrees btdc mark and not a TDC mark.

Alan


Further on this
The reason you are seeing a 50degree dwell for a 15 thou feeler gap is probably slight wear in the distributor spindle bush which is why you always need to use dwell for final points measurement ( Feeler gauge will just put you in the ball park) because it takes care of any wear and centrifugal momentum in the distributor. Check the dwell on tickover and again at 3000rpm, ideally there should be little change.

Alan.
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PostPost by: SENC » Mon May 25, 2020 2:48 pm

Thanks again. The distributor "innards" looked surprisingly good and all moved freely - so just a quick cleanup and a touch of oil and back together. The points are less than perfect and most certainly contributed to what I was feeling with the feeler gauges, so probably not as far out as I thought. I'm going to check to see if the neighborhood parts store has a set this morning, but knowing that is unlikely have cleaned them up the best I can for reinstall if necessary and further testing.

IMG_20200525_104627.jpg and

IMG_20200525_104707.jpg and
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PostPost by: SENC » Tue May 26, 2020 1:20 am

No luck on the points locally. Before I order the wrong thing, can anyone here visually identify the Bosch distributor model or points part number from these pictures (I couldn't find numbers on them).

IMG_20200525_203524.jpg and

IMG_20200525_203425.jpg and

IMG_20200525_203326.jpg and
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PostPost by: disquek » Tue May 26, 2020 3:19 am

Hi!

I have a '62 Super 7 Cosworth also.

I'm having some issues with the DCOEs. I think the steep angle that the original manifolds create causes issues.

Would you mind measuring the angle of the carbs on your car?

Thank you!
-Kyle

9cBAL8lygoNNshQXLHenARoK-zBKzkek7IoQeAOMiFQpX92IB.jpg and
'70 S4 Elan - Cosworth BDP & Spyder Chassis
'62 S2 Super Seven Cosworth
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PostPost by: vstibbard » Tue May 26, 2020 8:49 am

There is something going on as your engine is sitting way to high on the exhaust side, on my S2 the carburettors are pretty close to level.

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PostPost by: alanr » Tue May 26, 2020 10:31 am

SENC wrote:Thanks again. The distributor "innards" looked surprisingly good and all moved freely - so just a quick cleanup and a touch of oil and back together. The points are less than perfect and most certainly contributed to what I was feeling with the feeler gauges, so probably not as far out as I thought. I'm going to check to see if the neighborhood parts store has a set this morning, but knowing that is unlikely have cleaned them up the best I can for reinstall if necessary and further testing.

IMG_20200525_104627.jpg

IMG_20200525_104707.jpg


Unfortunately I can't help with distributor number or even the original Bosch points parts number but the correct ( Bosch repackaged)Ford part number is Motorcraft EDP38 for the points. Used on a large variety of Ford UK cars at the time...Fiesta etc. Maybe you can cross reference.
Lots of pattern part manufacturers have made these over the years with varying degrees of quality.
Also beware when searching there are similar looking but opposite hand Bosch points used on many others of similar vintage e.g VW. BMW at the time.

Alan.
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PostPost by: disquek » Tue May 26, 2020 12:55 pm

Exhaust side? Is yours a cross flow?

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