New +2 owner with a few questions

[Lordflashart]

Gentlemen,

First I'd live to introduce myself.
My name is Paul and I live in British Columbia. I've been into old cars for a long time and own a triumph TR4, an Austin Healey Frogeye Sprite and as of last week a 1969 Elan +2.

Now for my questions!

The Elan needs a fair bit of work, but the main problem is the engine. There was a tapping noise when it was running, then it promptly dropped an inlet valve and trashed the head and number one piston. Not a good first day!

Anyway, I've a couple of leads on a new head and have removed the damaged piston. Thankfully the bores are undamaged. However it looks like all of the inlet valves have been contacting the pistons.
The Pistons have written on the crown that they are 15 thou o/s but on measuring the bore, it appears to be standard. The piston has "hepolite 17193C" written under the skirt.
So my questions,
Is the 17193C the standard sized piston? And is the cause of the valves hitting the pistons likely just incorrect valve timing or is there likley another problem?


Thanks in advance

Paul

[Sea Ranch]

Paul, welcome to forum and Lotus ownership, from another British Columbian (I'm in Surrey).

You need help! I cannot give it, but others will be along shortly; there are some very generous/helpful twink experts on this forum.

While I'm at it, where did you acquire the car? Is it local or imported?

Regards,

Randy

[rgh0]

HI Paul

I am not familiar with the Hepolite number but generally the casting numbers used by piston makers are utilised for a number of different piston types so it may not relate specifically to a twin cam piston.


A number things could cause a clash between valves and pistons

1. Piston deck height to high ( or block decked to low)
2. Valve / Camshaft timing incorrect
3. Non standard high lift camshaft incorrectly installed
4. Piston cutouts not large enough ( or large valves fitted that don't match the standard piston cutouts)
5. Valves in wrong position in head ( seated to close to pistons or head shaved and valve position not adjusted)
6. Non standard crank and rods fitted incorrectly - eg a poorly done conversion to 1600 stroke crank)
7. I am sure inventive people have found a few other ways I have not seen yet.

If its a Weber head it is probably worthwhile seeing if you can get it repair welded cheaper than a new or second hand one. If its a Stromberg head then you should be able to source a replacement reasonably cheaply.

Some photos of the head and pistons would help diagnose the cause but it is most likely just incorrect valve timing as you surmised.

regards
Rohan

[billwill]

You sound as if you already know all about it, but if you need to check valve clearances later, this is a topic describing how I did a clay test myself.

lotus-twincam-f39/clay-test-checking-clearance-between-valves-pistons-t26441.html?hilit=clay

[512BB]

I can confirm that the nos 17193C are cast into both the standard and +15 thou pistons.

Leslie

[Lordflashart]

Thanks for the reply chaps,

Randy,
The car is a BC car and I bought it in Kelowna. It's not been driven for years though.
I've found a local guy who will weld up and repair the head and I had my engine builder measure the pistons and he agrees they are standard sized.
So all I need is new valves, new pistons and the head repaired and I should be back in business.
The car also needs the rubber doughnut on the drive shafts and both sill members replaced. Any suggestions where to source them? I know most of the British suppliers but it would be nice to get them closer to home!
Regards

Paul

[oldchieft]

So all I need is new valves, new pistons and the head repaired and I should be back in business.


Paul

Sounds easy when you say it like that!

Jon the Chief

[billwill]

If you are actually needing to replace all four drive doughnuts, you should probably seriously consider changing to CV Drive shafts at the rear, because doughnuts are expensive and generally the quality of the rubber and joints is not as good as it was in the 1960s-70s. Total cost of the CV shafts will be greater than 4 doughnuts+bolts, but will last a LOT longer.

There is MUCH discussion on this website about the constant velocity drive shafts, so no point in repeating it here. The key point is that on a two-seater Elan the CV joints don't handle the original amount of droop when the rear suspension is at its lowest point, so some form of droop limitation is required. With the +2 with longer shafts the angle of droop is not so severe, so general consensus seems to be that they do not need droop limitation.

~~~~~~~~

The search for [CV shafts] found nearly 400 hits on this forum; can someone suggest which is the best topic for this new member to start reading.

http://www.lotuselan.net/cgi-bin/search ... 0&zoom_cat[]=-1&zoom_and=1&zoom_sort=0

[Bud English]

Paul- As for part sources a little closer to home, I'm a satisfied customer of Ray Psulkowski, at R.D. Enterprises. He's in Quakertown, PA and here http://www.rdent.com/. He has a section on his site with the parts manuals available. Quite helpful. There's also Dave Bean in San Andreas, CA, http://www.davebean.com/. I've bought from them in the past and been happy with the parts, prices, and service. They're not in Canada, but they're closer and both quite helpful with info over the phone.

[roblotus79]

Welcome!

I'm also in B.C. North Van in fact. Post some pictures so we can see. Looking forward to seeing the car some day.

When I got my car, I had to do donuts as well and with the cost of them, I went with the CV kit from RD as well. It comes with new diff output shafts and works great. No droop limiters required on the +2. Doing this will also give you the opportunity to fit their differential strengthening piece (really cheap) that is highly recommended.

If you want an expert local opinion on the engine and it's build, I'd recommend contacting Richard Chong at Richmond Auto clinic. He is a great guy and good with the twink.

Cheers

Rob

[Lordflashart]

Here are some pics

[roblotus79]

Looks good and very complete.

Good luck with the rebuild

[Sea Ranch]

Ah, pix of the Okanagan. Spent four happy years up there myself.

In regard to sill members, I opted to order from UK as I was interested in the stainless units from SJ Sportscars. I can tell you that from my experience, they were good to deal with and I'm very pleased with the product as it seems very accurately made and the metal quality looks good (it's non-magnetic throughout, which generally means a good quality of stainless).

Otherwise, heartily concur with Bud's assessment of Ray at RDEnt. Great to work with.

Another interesting local supplier just coming on-line, so to speak:
http://www.lotus-mistry.com/

Will watch with interest to see if he can make a go of it in the lower mainland and on-line.

Regards,

Randy

[Lordflashart]

Thanks again for the tips gentlemen.

I've now got stainless steel sills, Pistons, and valves on the way from Blighty.
The interior is all ripped out and I'm cleaning out the years of mouse droppings.
The damaged cylinder head should be back from the welder on Monday, and then it'll be off to the machine shop for new valve seats and guides and the new valves fitted.

Once I get all the parts it should only take a few days to get it all assembled and ready to go.

Only problem I have is that if looks like 165/80/13 tyres are not obtainable around here.
Is there any other size that fits?

If all else fails, Longstone tyres in the UK do free shipping on their Michelins!

Paul

[mbell]

Try Vredestein Sprint Plus they do one in the right size available at coker.

Can also fit a modern sized 185/60 which are easy to find or a 175/70 which are closer to the original size but more limited options.