Main Bearing Cap Bolts

[rikiwho123]

Hi to all i'm in the process of rebuilding my 1300 spitfire motor and was ordering new hardware for it ; now my main bearing caps have bolts with no washers and yet my Haynes manual shows a lock washer being used in the assembly ; so do i buy new bolts with washers or without and do you always replace the bolts after a rebuild . thanks Rick.

 

[TR3driver]

I don't have any Spitfires, but based on my experience with other Triumphs, I would definitely replace the lockwashers, if you decide to use them. Be sure to get the right ones, hardware store stuff may not be strong enough.

I may be in the minority, but I don't normally replace the bolts unless the originals are damaged. One way to check for damage is to spin a nut up the threads and check that it spins easily all the way to the end of the threads. If it gets noticeably tighter before the end, the bolt is stretched and should be replaced. Never use a tap (or thread chaser) to clean them up.

 

[Andrew Mace]

At least one spare parts catalog I looked at shows a simple lock washer used for the main bearing cap bolt. That's for the later "large crank" 1300, which I'm guessing is what you have?

Oh, and the listing (at Canley Classics gives "WL210" as the lock washer part number and "HB1024" for the bolt.

WL[0]210 is 7/16" inside diameter and .78" outside diameter.

HB1024 is 7/16" UNF, 3" in length.

Not that I'd necessarily use the very cheapest quality bolt (or even washer) for something as relatively important as a main bearing cap, but the point is that the above are "standard" (no pun intended) hardware store items as opposed to a bolt or washer or whatever made specifically for a peculiar application.

Again, Canley Classics has the entire secret code book, a.k.a. Standard-Triumph Hardware Catalogue online! Most useful!

 

[TR3driver]

Oops! Somehow, I misread the question, thought the subject was connecting rod bolts. My bad, I'll fix my earlier message.

 

[rikiwho123]

Ok then i was going to replace the rod and main bolts anyway but just needed some extra thought on this subject about the washer since my motor had none; thanks guys.

 

[Andrew Mace]

Just so you know...unlike the main bearing cap bolts and washers, the connecting rod bolts ARE a special item (not off-the-shelf-at-Home Depot bolts)!

 

[rikiwho123]

thanks Andrew i got some HD BOLTS from spits bits for the rods but keep the advise comming rick.