11D crank/rod questions

[Anonymous]

Further to the nasty sounds coming out of my engine last month, my mechanic finally got a chance to open things up. Doesn’t seem to be nearly as bad as it could have been, but not ideal either. Apologies in advance for anything poorly described – I’ve never had to go into a bottom end before, and am just trying to do some legwork to make my mechanic’s life easier re: ordering parts.

So, it looks like the #1 rod big end bearing spun and is toast. The shell bolts were quite loose. Measurements on the crank pins are as follows.
#1 47.55 mm
#2 47.955 mm
#3 47.929 mm
#4 47.955 mm

I believe standard was 48.000 mm so it seems like the crank hasn’t been ground before.

Questions:
– Since I’m trying keep costs down, I’m hoping it will acceptable to grind the crank to 0.50 over and order a set of 47.50 mm bearings, and replace the #1 rod. Is this reasonable? I understand that 11D rods may only be sold in sets.
– Is there anything that has to be replaced when re-installing the crank, e.g. shims, keys, etc?
– Anything else to be aware of re: parts or installation?

Thanks in advance for the education. I did look through the old FP tech articles but didn’t find anything this detailed.

[Anonymous]

Hi

You have probably seen it but here is OSL282 rebuild
http://osl282.info/Engine.php
and of course there is a lot of information on tripyrenees project.
Sorry do not know on the con rods.

Dave

[Anonymous]

Thanks Dave.

Anyone else? Wondering if I asked a really hard question or a really dumb question.

[Anonymous]

Hi Bruce

Why don’t you try phoning John Gillard +44 (0)207 358 9969 Classic Restorations in London, he is supposed to be very helpful.(I believe Mondays are not good ).Or try e-mailing someone like CAS,Jose Franssen etc I think one of the problems is there all mad busy with the ICCCR in Holland coming up.

[Anonymous]

Hi Bruce,

The original big end diameter was 47.990 – 48.000mm ( ref – http://www.ctaservice.se/tek/tekinfo.htm). Shells are available in steps of +0.25mm from all suppliers.
I think you may need to go +0.75 to ensure #1 cleans up. Your grinder will know best.
All the suppliers seem only to list con rods in sets of 4. Individual engine builders like John Gillard may have a single one knocking around (new or second hand). Maybe the major suppliers too – even though they don’t list them they have already broken a set. Worth calling Chris T at TOC Spares too, I believe he has more than is on the spares list.
Leo Quinn is advertising a garage clearout of enginer spares in the back of F-P – leoquinn1950@gmail.com.

It’s a very open question as to what else needs to be replaced. There’s a thrust washer at the timing gear end of the crankshaft which needs shimming to get the correct end float. So you may need to get some more of them. They come in 0.1, 0.25 and 0.5 mm thicknesses, 461125, A, B, C (Franssen and CAS have them).
of course you’ll need the sump gasket set and graphite cord crankshaft oil seal. Chris T knows what’s needed and what’s in which kit.
Chris

[Anonymous]

Thanks for the replies. I ended up talking to Brad Nauss in New York and he provided the spec info. He also appears to have the parts although as Chris says it looks like the con rods come only in sets.

[Author]

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