The Triumph Dolomite Club - Discussion Forum

Because anyone using a stag engine will be hunted down and used as bait in my next deep sea fishing trip, they are the devils spawn.

that'l be a plenty good excuse then for me to pop a rover one in then

There's nothing wrong with Stag v8 engines!

In standard fettle they produce more power then a Rover v8.

Yes, BHP per litre the Stag engine makes more power than the RV8.

But the Stag engine has the same technologically advanced waterpump as the 1850 / TR7 / Sprint with only double the number of cylinders to cool, it has the same whacky angled head studs as the 1850 / TR7 / Sprint, meaning its heads slide about, it has twice the number of super-length cam chains that current wisdom suggests need changing every 25k and it weighs about the same as my house.

The only redeeming feature of the Stag engine is the soundtrack. Everything else to do with the Stag engine is completely hopeless and rubbish.

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Vindicator Sprint, Honda Fireblade RRX 919cc, re-powered by AB Performance. Quick.

I'm not going to hijack a thread by debating the merits of the Triumph V8 vs the Rover v8, that wasn't the point of my initial question. Yes, the Triumph unit has its flaws, as does the Rover V8, the only difference being that the Rover unit had more money thrown at it by BL and Rover and thus more development.

I have had plenty of Discovery V8s, the 3.9's I ran to over 120K and the Disco 2 4.0 only lasted 80K before I had to get Overfinch to replace the engine (With a 4.6!), they have all suffered from camshaft wear, timing chain stretch, cracked bores and the 4.0 dropped a valve at 800 miles. Yes, 800 miles, I had owned it for approximately 2 weeks!

The cooling issues in the Triumph V8s were caused when the bore was enlarged to increase capacity rather than changing the stroke, resulting in restricted waterways and warped heads, as well as the main bearings being inadequately sized and drive gears shearing resulting in water pump failures.

What I am saying is that with modern upgrades and sticking to service intervals old issues, Rover, triumph or whatever, can be solved. Thus nowadays these engines are not bad at all.

Anyway, how is the conversion progressing? Where did the 3.9 lump come from? Old Range Rover unit?

Don't they have smaller bores than an 1850, each bank only displacing a shade under 1500cc though?
Apart from when you want to remove one, then sliding about is the last thing they want to do!

Yes, the soundtrack of the Stag is more musical than that of a Rover in a stock application, but surely when fitting one to somewhere it wasn't intended to go leaves the exhaust builder carte blanche to make it sound better. I'd go for the physically smaller Ford Sierra XR8 5 litre engine, although iron, it's only slightly heavier than the old Buick engine and it somehow manages to sound even better than the next best.
But hey, the Rover motor's easy to find, easy to tweak and the spares won't bankrupt the builder.

stags are massively oversquare,,,bore and stroke being 86x64.5 which is why the stag can rev so high,,,,piston speed being similar to a rover v8 when its at its rather limited max revs
rover is 89x71,,,,and the bigger variants use a 94mm bore with differning stroke lengths to give up to 5.5litre so a torque curve on a 5.0 rover starts at 250lbft and slowly goes to 350,,and gradually drops,,,,thats the sort of torque curve i'm after so it'll pull electrifyingly in any gear

big rovers suffered at the hand of lean efi fueling maps overheating the cylinder liners ,,and causing them to drop/overheat etc

a stag will give about 160 lb/ft,,,,but thats not really enought to go up a gradient in top gear with a highish ratio diff and still have performance
rover 3.5 will give 200lb/ft from standard ....3.9=225,,,4.2=250,,,,4.6=275,,5.0=350,,,all these torque figures happen at arround 2500rpm too,,,,hence the limited power output,,,but enourmouse higher gear performance from low rpm

i'd have thought about a 5.0 ford with its decent breathing cylinder heads,,,but they tnd to command big purchase prices even if needing a rebuild and would then need a BW T5 or tremec gearbox if i wanted to go manual,,which are scene tax'ed to heck lol

i reckon the sound of a v8 is heavily influenced by the exhaust,,,ive heard later 302 mustangs that sound like a proper v8,,,and some earlier one that were abit boring to listen too due to really bad silencers

i'll hve to find out what exhaust syste this uses as if it sounds like this, http://www.youtube.com/watch?v=XHaesH36_aI but goes like this,, http://www.youtube.com/watch?v=MKsse0hq ... re=related then i shall be very happy with it
the second clip has similar acceleration between 70-100 as my skoda (which is alot faster than my old 1500 ever was) does 0-30 lol

well its been ages since i last did anything to this car due to that stage where time just slips by,,anyhow now that my other project has become a useable daily driving car i can turn my attention to BLs finest

ive been pondering brakes for a good while now,,basically ive finished the brake upgrade,,but decided that they probably wont stave off fade well enough so they are the 'intermediate' brakes just for the mot
anyhow i fitted some mk1 gti disks to the hub by turning the hub to 65mm where the disk mounts on,,and redrilling the disk to suite the hub pcd,,then calipers became something of a quandary especialy as when i was down at the scrapyard and couldnt find much suiteable or in good order,,,,eventually found a rover 45 2.0td and its calipers looked fairly decent,,big pad area and decent mounting points so scored those for like £10
offering up the claiper to the disk looked very promising so i made a bracket out of 15mm mild steel plate and ensure the pads covered the disk properly

i hade to hacksaw and chain drill the bracket out as laser cutting was abit too pricey for my liking

the setup requires the caliper to fit forward of the kingpin to clear the steering arm due to its size,,and tr7 steel wheels give about <1mm clearance (although gt6 steelies give about 10mm) so i'll go for some 14x6 MGF spare steel wheels lol

the next brakes i think will be bmw e30 front disks @ 260mm or 256mm vw ones with the same rover calipers

the rear axle is getting some mgf rear disks and mgf calipers which in the case of the disk fits directly over the 3.75" hub pcd the area to look at however is that the taper roller bearings will need new shims made now that the drum back plate has been omitted

this website >>> http://www.apecbraking.co.uk/search_size.php has been very usefull when checking what disks are likey to fit

You may want to look at this for your rear disc conversion:

viewtopic.php?f=3&t=2157&st=0&sk=t&sd=a&start=60

Uses Rover 800/MGF calipers and escort disc.

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Finished with Main Engines and Steering....

1981 1500 HL man/od
1972 Series 3 Land Rover diesel
2007 MX5 Sport
2010 Citroen C1
1993 Gas Gas GT32

well untill 5 weeks ago this car has sat on the drive doing nothing as a bare shell while the estelle has been taking daily driving duty so now that both cars mot has gone ive been using all my free time fettling it (6 day working weeks at good ole unipart havnt helped )

first job was to finish all the mounts for the engine and position it so it was straight and true on the engine bay (didnt finalise the gearbox position due to the prop shaft running angles needing consolidated

anyhow fast forward a week and the engine was fitted and the front suspension/brakes steering all fitted up and the bolts torqued up (removed the polybush's to fit some of rimmer bros finest standard ones as the car is more smooth cruiser than racer)
i had thoughts that the master cylinder servo would clash with the rocker cover,,,but not even remotely cleared by 15mm (engine central to the bay)

the closest rad i could find so far to fit was a late saab 900 turbo item,,,shame it was impossible to remove from the car in the scrapyard,,so i got a rover 2200 one instead
the waterpump was a rover p6 item which came with no pulley,,so rather than spend loads on ebay for one i got a machine mart 150mm v belt pulley and lathed it to fit
the manifolds are p38 items cut down and aranged with the outlet at the front (2" mild steel pipe runs unde rthe subframe to a silencer under the seat,,then out the side) but this is a temp solution as i'm aimin to get the down pipes running right up tight to where the inner TCA bush's are as the ground clearance would be better and having them closer to the wheels helps further with then not hitting the ground

once the engine box was in place i could make up the adapter for the 1500 speedo cable to fit the 5 speed the inner cable fitted directly,,and the outer needed just a collar made on the lathe
then it pass's through the tin gearbox cover straight up the back of the dash
then one the lid was bolted in place i could fit up the interior again (basically everything it had before)

once that was sorted i cleaned up the rear suspension parts,,fitted up new bushes again and some unknown dampers that appear to have 1" less droop than stock and harder damping
once the axle was in position the shortened and quite heavy duty ldv 200 propshaft could be fitted up which meant making a center bearing bracket hanging off the origional mounts and to the right size so that all the UJ running angles at standard height were around 1-2Degrees


this pretty much concluded the running gear fit up which went relatively smoothly (prop was easiest ,,cut it down with a hacksaw,,took it to commercial propshaft services in team valley and they welded and balanced it for a reasonable £88 (would have been less if it was a straightforward single prop)

the clutch master cylinder needed fitted inside the car so i got a landrover remote reservoir item and made an extension to fit it to the 1500 pedal mount
3/4 to 7/8 bore seems to make the clutch reasonably light

and as i couldnt afford to buy a remote reservoir for the clutch (could even justify the £10 for one) i cut down a emty disposable gas bottle and welded a brasso top to it

the back brakes was next on the list these are MGF disc's which with a small amount of modification to the register on the hub fitted directly (even the small securing screws matched up with these i went for lucas rover 45 rear calipers which needed a mount bracket and a 20mm spacing bar made
the handbrake cable needed some small modification to fit the calipers,,,but would have needed any if i'd managed to fit rover 800 calipers
and indeed that rust hole amazingly is the only area of rust in the entire sill area

and finally the battery was relocated to the boot on a angle iron frame and some gratuitously ott amplifier wire was used as the starter cable (runs under the carpet alongside the brake line

A work of genius . So nice to see a v8 conversion on a car that is so well designed and thought through, terrific stuff.

Can't wait to hear the soundtrack that matches the pictures. Some fabulous engineering being done here, and all so well thought out. I'd guess that we'll see this ANIMAL at some shows v. soon?

wow! that looks amazing especially considering it looked like a roadside conversion ha ha . How fast do you think you'll go? 140 maby? i would not want to pay for the car insurance on that thou!

Insurance should only be about £400/500 quid, if that, although obviously depending on your situation it could be more!

ive no idea on the performance as all the cars i'm used to have been between 44 and 70bhp so this should theoretically feel abit more lively ,,not that i plan on driving it to the edge tbh,,,more cruising trying to eek out some level of economy due to my bottom of the ladder employment and being content to drive like that

i think it would probably max out at 130 (if going around knockhill/croft etc )

only got one quote for it with a few unfavourable issues,,one crash, 1 years NCB, rubbish northern postcode and just me using it was 1100 for the year

i'm hoping to get it to the RR meet down at somerset but its completely unknown how it will behave and needs MOT tax and the expensive insurance all within 2 weeks so basically it has to pass the test first time