The Triumph Dolomite Club - Discussion Forum

It does start with this: The engine of my daily 1300 did die. The axial bearings were lying in the sump and the cilinderblock and cranckshaft are damaged. Why buying another 1300 engine to rebuild when there's enough 1850/sprint engines in the shed. The main disadvantage of the 1300 was the engine. Using a bigger engine i could tow my caravan also with this car.

As it was running on LPG the new engine has to be also. The desired compression ratio will be 1:13 for maximum efficiency.

The plan is to rebore my old 300.000km 1850 lpg injected engine to 2 litre and use and 1850 head. The 1850 head has a smaller combustion chamber as the tr7 variant and this way there's no need to extreme skimming of the head. I used to skim 1850 heads under an angle to have the maximum effect but the max is 1:9 -1:10. Otherwise the valveseats are skimmed out of the head. The engineblock i did modify already many years ago so it saves time not to blueprint as it is already done. All rotating parts were also lightened and balanced already.

I'm going to use a tr7 single carburetor manifold. Long tubes for better lpg mixing and low rev torque. I'm not sure yet what carb to use, one hs6 or one hs8. This way it is easier maintainance and adjusting. Dual su's and lpg are very sensitive for out of balance.

The gearbox will be a single rail 1850/OD.

To be continued..

Jeroen

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I for one will be watching with interest.......








Ian.

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Ready in 2 weeks time for the 'oliebollenrit' ??

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Ronald
Club Triumph Holland - Dolomite Registrar




www.triumphowners.com/tahitisprint

You have, I presume got a spare 1850 subframe to go with this? And a decent axle, I suspect the 1300s 4.11 won't last long with that beastie in it!

Steve

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'73 2 door Toledo with Vauxhall Carlton 2.0 8v engine (The Carledo)
'78 Sprint Auto with Vauxhall Omega 2.2 16v engine (The Dolomega)
'72 Triumph 1500FWD in Slate Grey, Now with RWD and Carledo powertrain!

Maverick Triumph, Servicing, Repairs, Electrical, Recomissioning, MOT prep, Trackerjack brake fitting service.
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It will not be THAT a beast! Just a single carb 2.0 on LPG. Aiming on 110-120bhp at the wheels. It had in 1850 form lpg injected about 110hp at the wheels, about the same as a std sprint. I did run it all those years with a sprint gearbox but a normal 1850 diff with a 3,9 ratio.

It could manage 13km on one liter lpg but i do not want to fit the injection system on it. It is really a very original car and don't want to modify too much. It must retain the could be all original factory look. My home/work distance did shrink about 95km a day so the km/l is not so importand but should be with a conventional setup about 9km on one liter lpg.

Ronald, it was the plan but i was too enthoustiastic. It will be the volvo again this year and Yvonne in her 2500.

Jeroen

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Classic Kabelboom Company. For all your wiring needs. http://www.classickabelboomcompany.com

1850 diff is 3.63.
If you had a 3.89 it must have come from a 1500TC...or maybe a dutch 1500 Toledo?

Single carb TR7 manifold? Where does that come from?

Jonners

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Note from Admin: sadly Jon passed away in February 2018 but his humour and wealth of knowledge will be fondly remembered by all. RIP Jonners.

Yes a 1500 diff but not a sprint type rear axl. Just std 1300/1500/1850 type.

The manifold is of a very emission lean tr7 type with low compression, single carb and an airpump. USA spec but not so common there also.

Jeroen

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Classic Kabelboom Company. For all your wiring needs. http://www.classickabelboomcompany.com

Tonight was conrod night. I'm selecting 4 conrods that have about the same weight. It can varie 30 grams per rod sometimes in an std engine and that is way too much. The next pictures are the basic lightening of the rod. As new rods don't have a mark in them i stamp my initials in them for not mixing up.

The start is with the bearingcaps. When you are having these the same weight it is easier balancing the rotating and translating weight later. Then lightening the small end but don't forget to re drill the oil collecting hole. Otherwise the piston pin has less lubrication. The next step is to have all the rods less cap the same weight. This is the basic lightened rod. Next week i'm going to balance them. In the last picture of an old rod you can see where to take some material for final balancing. When all is done it's rounding the edges and shotpeen all the grinding scratches out.

Jeroen

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Classic Kabelboom Company. For all your wiring needs. http://www.classickabelboomcompany.com

_________________
Classic Kabelboom Company. For all your wiring needs. http://www.classickabelboomcompany.com

_________________
Classic Kabelboom Company. For all your wiring needs. http://www.classickabelboomcompany.com

Nice work, thanks for sharing.

Tony

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Membership 2014047

All balanced and ready for shotpeening. Next step is putting the o/d together and wait for the engineblock and head to arrive from boring/honing/skimming. After some calculations it isn't possible to have a 1:13 compression ratio. 1:12 is max. The combustion chamber is not that much smaller than a tr7. I'm having the deck skimmed so that the pistons are 0,75 above the deck and use the compressed headgasket thickness as extra space to decrease the combustion chamber volume. The head isn't skimmed under an angle but max straight. This will be about 0,5mm. This way the valves have enough clearance.

Jeroen

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Classic Kabelboom Company. For all your wiring needs. http://www.classickabelboomcompany.com

Spray time It is now a 2 liter and has the deck skimmed and flush with the crankshaft bore.

Jeroen

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Classic Kabelboom Company. For all your wiring needs. http://www.classickabelboomcompany.com

The 1850 head is max skimmed and ready for some enlarging of waterholes and ports. The ports are not going to be widened only smoothened and matched with the manifolds. The ports cannot be enlarged much. They are close to the water jackets i discovered a few year ago. An internally cracked head was a water drinking engine mistery. All the inlet port holes had cracks into the watersystem.

The combustionchambers have still to be matched also.

The guides are replaced and the inlets machined to have less resistance so slightly better flow. Jeroen

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Classic Kabelboom Company. For all your wiring needs. http://www.classickabelboomcompany.com

I remember there used to be higher spec conrod bolts available for the 1850/TR7/Sprint bottom end; these, I was told by someone I trust implicitly, being the part that limits the engine to 6500 rpm.

Are there any options still available, does anyone know?

Graham.

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The 16v Slant 4 engine is more fun than the 3.5 V8, because you mostly drive it on the upslope of the torque curve.

Factory 1977 TR7 Sprint FHC VVC 697S (Now all of, but still needs putting together)
B&Y 73 Dolomite Sprint UVB 274M (kids!)
1970 Maroon 13/60 Herald Convertable (wife's fun car).