Square 4 big end shells

[sbeagle]

Hopefully someone will be able to help me.

The specification for the crankshaft big end journal is 1.3745" to 1.375" (which is a very tight tolerance)
I am thinking of fitting a Morgo oil pump and I am measuring 1.370", 1.373" , 1.373" & 1.374" on the 2 crankshafts. The biggest is 4.9212 thou (1.370")

Looking at Draganfly they supply standard, 10 thou, 20 thou etc. Do I need to get the crankshaft reground to 10 thou?

Does anyone know who makes shells to suit my tolerances. I have a set of 2 thou (0.002) big end shells.

Many thanks Simon

[Roger Gwynn]

.0005" tolerance is pretty standard for shells, modern vehicles will have even tighter tolerances. The shells are produced to fit the sizes given and for set undersizes rather than making them to suit individual crankshafts. You should have all the journals ground to -.010" as they are all outside the limits, which will cause rapid failure. Your local automotive engineering workshop should be happy to measure the journals and advise you.
Apologies if I have misunderstood the question.

[sbeagle]

Many thanks

The next question is can someone recommend someone near Junction 11 of M25 to regrind the crankshafts?

Also does anyone have the sludge trap screws 1190-37 (I believe they are 1/4" 26 TPI BSF x 7/16" CSK)?

Regards, Simon

[simon.holyfield]

Many thanks

The next question is can someone recommend someone near Junction 11 of M25 to regrind the crankshafts?

Also does anyone have the sludge trap screws 1190-37 (I believe they are 1/4" 26 TPI BSF x 7/16" CSK)?

Regards, Simon

This outfit looks good, not tried them myself yet.

http://www.seager-engineering.com/

[Paul Gasson]

I know nothing about square fours but I saw a set of -0.002” shells on eBay earlier which the seller identified as suitable for a square four. Might be worth checking to see if they help?

[Julian Murphy]

I have used Seager Eng.

Very good.

Recommended.

[john.davies]

I used T & L Engineering near Bedford to do my bottom end for me including grinding and cleaning out cranks, new main bearings/ crankshaft bushes and fitting club rods with the new shells. They have a lot of experience with SQ4's as I believe the current owners father, who set up the company, had them.

[sbeagle]

Thanks for the help and suggestions