dolomite 1850 engine

[DaveLynch]

hi guys iam posting this for a friend off mine as he is not on pistonheads . The problem is he has a 1850 dolomite with a poorly engine which he has had loads of grief with over the last 18 months and expensive to have fixed , so he is thinking off swapping it for a 1500 engine and box which he says are bullet proof , has anyone done the conversion or knows anything about it ,if it will just go straight in ? exhaust fitting ? is it the same prop shaft etc , any thoughts or comments would be gratefully appreciated
many thanks Dave

[//j17]

It's going to be possible - but with a few changes are required.

The 1850 engine's the Sprint one but with a conventional head, rather than the 16v one, so for a start it's a cross-flow design unlike the Triumph 1500cc SC engine putting the exhaust manifold on the wrong side. Being a slant vs. vertical 4 I'd expect the engine mounts to be different too, and the wiring, and...

Probably cheaper to buy a whole 1500 Dolly.

[davepoth]

You'll want the subframe as well IIRC but apart from that it's a direct fit, the shells are identical. The bellhousing can be swapped too so you don't actually need to swap the gearbox.

I wouldn't go for a 1500 though. It's less powerful, less economical, and because it has a very long stroke it hates to rev and is quite weak. It can be made better but not cheaply.

What exactly is wrong with the 1850 engine?

[GavinPearson]

I have owned a number of Dolomites - a 135, 4 Sprints, 2 1850s and a 1500. The owner of the blue car in his piece asked me to drive his car when newly acquired so he could get a second opinion on the way the cars are supposed to drive, handle and sound.... http://www.automobilemag.com/reviews/driven/1004_t...
I have also helped a prominent US journalist enthusiast get his cars into shape - these are cars that are reliable in 95F weather.

Before condemning the 1850 engine the best thing to do is to see if it can be salvaged. If the engine runs, has good compression and doesn't have knocking bearings it's saveable.

I would change the oil, fit new air & oil filters, clean the fuel pump filter & fit a new set of spark plugs and a new thermostat. If the heater generates a lot of heat then the water pump is working OK.

I would flush the cooling system with radflush, flush it through with water repeatedly afterwards and then use good quality conventional coolant in a 50/50 mix.

The simple modifications I have found make a very significant difference are the fitment of the Piranha / Newtronic electronic optical ignition system and Gross jets which fit in the carburetor float bowls. Then set the engine timing, adjust the carb throttle plates, jets and idle speed and the engine is fixed. After this there is actually very little to go wrong.

If the 1850 engine is broken then honestly I would fit a TR7 unit and transfer over the Dolomite sump. It is the least amount of work to fit and the rest of the car is more than up to the job. But even then, if you want the car to be reliable then you need to do everything I have on the list - no skimping.

[DaveLynch]

hi guys thanks for the info he had a lot off problems with over heating he did well started the round Britain last year and the water pump give up so new pump fitted ok for a while now its started again with similar problems , removed the water pump which is shot again and its damaged the gears on the shaft which drives it and he has been told its an expensive job to replace the shaft . And he may be interested in a spare 1850 water pump if anyone has one to at least get it running again while he decides which road to go down
thanks dave
ps I be away from the computer all weekend I going Scotland with my car for a meet with the Scottish lads

[GavinPearson]

DaveLynch said:

hi guys thanks for the info he had a lot off problems with over heating he did well started the round Britain last year and the water pump give up so new pump fitted ok for a while now its started again with similar problems , removed the water pump which is shot again and its damaged the gears on the shaft which drives it and he has been told its an expensive job to replace the shaft . And he may be interested in a spare 1850 water pump if anyone has one to at least get it running again while he decides which road to go down
thanks dave
ps I be away from the computer all weekend I going Scotland with my car for a meet with the Scottish lads

Unfortunately, if the jackshaft gear is damaged then he really is on borrowed time if he makes the repair by just changing the pump.

I would be tempted to just fit the TR7 engine at this stage.

One common issue with these engines is the water pump impeller spinning on the shaft. If the impeller is removed and a hole drilled 10 mm from the top for a 1/4" grub screw, a small flat can be ground onto the water pump shaft, allowing said grub screw to be Loctited and tightened to top any possibility of spinning when reassembled. Rimmer Bros should sell the water pump rebuild kits comprising all the seals necessary to make a good repair.

The 1500 is not exactly spritely and therefore a very bad route to go down to fix the car.

[davepoth]

If the jackshaft gears are damaged then it's a pretty big job to fix - the engine needs to come out to do it. As Gavin said, the TR7 engine is a good swap, (bolts right in, more or less identical except for the carburettors) but a known good 1850 engine would also work well. I'd go with whichever comes up first. The 1500 lump really isn't a good alternative.

[RichV6]

Its possible the block may be worn where the front bearing of the jackshaft is. This can be the result of over tensioning the cam chain. I went through a couple of pumps on my sprint before realising the problem. First pump may have been suffering from a batch that allegedly had been poorly hardened, the second was a known good pump. I ended up scraping the block and satrting again. Always wondered what a 2 litre 8 valve dolly would be like.

[MoggieMinor]

I had a Dolomite 1850 years ago, actually it was my first car. Even now I can still remember how powerful it felt compared to whatever it was I learned to drive in! Lovely engine when well maintained, I learned a lot from that car and would have another one tomorrow.

[GavinPearson]

RichV6 said:

Its possible the block may be worn where the front bearing of the jackshaft is. This can be the result of over tensioning the cam chain. I went through a couple of pumps on my sprint before realising the problem. First pump may have been suffering from a batch that allegedly had been poorly hardened, the second was a known good pump. I ended up scraping the block and satrting again. Always wondered what a 2 litre 8 valve dolly would be like.

A friend converted his over, it wasn't bad, but it was no Sprint. It was however infinitely better than a 1500.