Dolomite 1500 box and propshaft length for mk1

[myrkross]

I have chance of a Dolomite 1500 ( a twin carb thing 1974) it has a good engine and box, i am a little uncertain as to what box this Dolomite has.
I did a search on here and i cant make my mind up is the box is a triumph or marina box, now obviously it is matched to the 1500 engine so that part is sound enough. But i am not sure about the box itself being the same length as the older herald spitfire boxes, that look different.
What prop is best to get to fit both the dolomite tail spline and the early spit diff flange, or should i mix and match the flanges and cut the prop to the length it needs to be.
Is it worth me utilizing this dolomite box at all or should i just get a earlier spit or herald box and prop.
And the ujs are they interchangeable dolomite to heralds or are they totally different sizes.
Sorry for the twenty questions, but Triumphs and me are all new together.

[stevejgreen]

Re: Dolomite 1500 box and propshaft length for mk1

If you have not looked already, have a look at http://www.rimmerbros.co.uk/ItemList--Triumph-Dolomite-Sprint-Gearbox--m-659
It shows basic pictures of the different boxes and a trawl through the parts list will show similarities / differences between the triumph single rail boxes that are essentially the same as the Marina.
AFAIK there are few significant differences between the boxes but check the input shaft and its number of splines. Not a serious issue as the clutch plates are otherwise identical. You will also need to check speedo drives as differential and wheel sizes varied from the Marina.
Hope this helps.

[b_caswell]

Re: Dolomite 1500 box and propshaft length for mk1

The engine and box will go straight in but as your car has had a pinto fitted at one stage you may have to build the front engine mounts.
If reverse is left/press and fwd its a 3 rail--If reverse is right lift and fwd its the stronger single rail box.
If your lucky it may have O/Drive.
The gear box has a drive flange that will mate with most late Herald 13/60 and GT6 etc. If your lucky you can pull the prop shaft apart and mix and match the ends with one half(doing away with the centre bearing) and get a shaft of about the right length.
Dont thow the Dolly diff away as plenty of the later Mk2 Marlins can use it.
Hopefully the Dolly speedo will be matched to the gearbox from the same car.

[neiltechspec]

Re: Dolomite 1500 box and propshaft length for mk1

The O/D box is longer than the non O/D box by several inches. Can't remember how much exactly.

When I changed to an O/D box (single rail - ex dolly), I had to move the engine forward two inches, widen the tunnel & fit a shorter propshaft. I was lucky with the propshaft, picked up a NOS MGA one which was exactly the right length & just had to change the flanges.

An O/D box is definately worth the trouble of fitting, drops the revs by 500 rpm.

As for the 1500 Triumph Engine, I've had one of those in for quite a few years now. Not a great revving engine it has to be said and a very good idea to have the crank & rods balanced or you'll put a rod through the block.

With hindsight, I would not fit another of these old 3 bearing triumph engines. But if I had no choice would go for the 1300 as it's much more tunable & revs better.

[myrkross]

Re: Dolomite 1500 box and propshaft length for mk1

Thank you for the advice yet again, This Dolomite has the later gearbox with no overdrive.
And i have the prop shaft too, looks to be a little different on the gearbox mount than the marlin sliding bracket. But i have not had time yet to study this properly so it may be i am just looking at it all wrong.
When you look at the claimed specs for the Triumph 1500 engine, it has a fair amount of torque and at 125 kgs id fairly light too. In owners experiences, do these engines make the power/ torque triumph vlaim when in good order or are they very wild claims?
The 1500s do seem to get a poor report or two regarding the bottom end durability, but this engine is sweet and no issues i can tell and showed low miles at 52 though for an old car.
I don't intend to rev this motor off the scale and i cant see as any harm will come to it in my hands.
One other question,. Have any here modified the small fours for increased torque? a fair amount of info on hp increase with cams carbs etc, but little on torque increasing. Any ideas?

[silver-back]

Re: Dolomite 1500 box and propshaft length for mk1

ok my 1500 late engine with big valve head and 1.5 inch carbs delivers plenty of power it revs readily to 5,500 and with a piper cam and 40 thou off the head to increase compression it just about stays with my mates westfield (1600 kent with 40's)