A50 big end nuts

[chaz]

not wanting to re use my old big end nuts, looking on line I have the options , Ive got a pack of new Philidas ones but these are reduced diameter at flange face or the original style which are full hexagon face.
I would think from my experience building rail brake compressors, the full hex is the way to go. but
why are the reduced diameter an option?  why did I buy them? T100..
the 1969 parts book calls for 75-6594, none on ebay to compare, alternative numbers 40-0915, 67-1537, 68-0065, 70-2922 and 71-1957.
70-2922 show the reduced diameter, but a Triumph part number

if the reduced diameter ones can be used is the torque setting different?

[DAVE BRADY]

Hi Chaz,

Look at what SRM has or try C&D Autos.

Dave.

[chaz]

thanks Dave
just got a message back from Hackshaws, they only had 2 full hex ones and said the Triumph reduced diameter ones look a better nut, Im not convinced with only the small spotface and 50 odd year old surfaces to bolt down on to. might look better but do they do the same job?

one not got a web site, the other not got any nuts advertised, getting late in the day. as long as Ive got a bit of time, will start rebuilding over christmas. its been over 2 years waiting so no hurry

[DAVE BRADY]

Hi Chaz,

Best to email or phone C&Ds.

Dave.

[chaz]

any thoughts on the contact area and torque value for the smaller face?

[DAVE BRADY]

Hi Chaz,

With big end bolts and nuts I would rather not take a chance and I always replace the bolts and nuts together. The style of nut does seem to have changed with some having a smaller contact surface.
I would speak to C&Ds or buy a full set of nuts and bolts from SRM.

Dave.

[chaz]

thanks Dave, Ive already bought new bolts and have the later Triumph nuts so will have to ring around.
my thoughts, with the smaller diameter too much torque could see the nut damaging the face of the rods.

[DAVE BRADY]

Hi,

I think that C&Ds have Lester big end nuts.

Dave.

[Allan G]

Regardless of already having bought bolts on their own, I would get a set of ARP bolts off SRM, they are probably the best Big end bolts in the world for our old iron!.

The two should always be bought together (least I believe) and with the ARP you know what your getting is correct. Put the others on ebay, or chalk it up to experience.

[chaz]

cranks already built up with new nuts and bolts.
Ive never had problems in the past on the T'Bolts or Sq4's Ive rebuilt using other make parts.

[RGSJon]

Hi guys,

I can supply big-end bolts and nuts for large journal A10, A65 and A50 motors through my website eborbikes.com. 
They are made by the US company, ARP, who make the best fasteners there are for con-rods, with rolled threads and very high strength steel. 
They are available at
https://eborbikes.com/index.php?route=product/product&path=67&product_id=69

Regards,

Jon