The Triumph Dolomite Club - Discussion Forum

The sprint engine I am rebuilding came without a backplate, I have one, but no bolts. I now have the pistons in and the siezed engine now turns with new rings and bearings. However I have no way of screwing the backplate to the engine. Does anyone know the correct bolt size?

You will need 4 x HU856 (5/16" UNC and 3/4" long) and 2 x HU857 (5/15" UNC and 7/8" long). The washers are WP8.

Hope this helps.

Edit: Those are for the back plate on the cylinder head. For the engine block back plate you will need 6 x HU0806 (5/16" UNF and 3/4" long), 4 x HU0815 (5/16" UNF and 1 7/8" long) and 3 x HB0818 (5/16" UNF and 1 7/8" long).

Sorry for any confusion!

There are only six bolts holding the backplate to the block. These should not have any washers of any type on them so you should use some thread lock on the bolts.

Thanks, will order, shame you can't buy imperial bolts in a shop anymore.

Following assembly instructions in the little book of lies. It says backplate, flywheel, timing gear and then cylinder head in that order.

You should be able to get the correct bolts from a few of the usual suspects.

Note that the backplate location bolts have to be in different places for manual and auto cars.

If you put them in the right place for a manual car they foul on the torque converter to flex plate bolts.

Jonners

cleverusername wrote:Thanks, will order, shame you can't buy imperial bolts in a shop anymore.

Marine, agricultural and commercial machinery suppliers all do.





Ian.