What's the difference between 2Ltr, Sprint and V8 ?

[dursleyman]

I get 27-28mpg from my Sprint engined TR7 generally running about our local area in the Cotswolds which is fairly twisty and hilly.

Reading FI Spyder's cautionary tale above with the moving crank pulley, whoever built that engine messed up with the thrust bearings, either forgot them or put them in the wrong way round.

[supercass]

I suppose one mans commute is another mans motorway drive! A lot depends on how long your commute is and if it is sufficient to compensate for the excess fuel used from cold. I use a 1.6l Sensotronic car many days and it has an accurate computer. Average fuel consumption is over 37 but when starting from cold it reads about 11 mpg which increases as it warms up. I remember when my TR7 was new taking it back to the dealers as I thought the 12.75 mpg was poor. They didn't find anything wrong although the technician commented that that was more like a Rover 3.5 consumption. supercass

[FI Spyder]

Reading FI Spyder's cautionary tale above with the moving crank pulley, whoever built that engine messed up with the thrust bearings, either forgot them or put them in the wrong way round.

The guy that assembled it also did his Dolomite Sprint at the same time with no problems mind you that doesn't mean he couldn't have made a mistake. He also is the club expert on SU and Zenith carbs. He used to do concours judging on Jaguar cars. A year ago Bill took his car into a club members garage. He works on British cars and is the go to guy on the Island for Rolls Royce repairs (he just did a mechanical survey on John Lennon's Rolls Royce in Victoria (the yellow psychedelic one) for a pile of money. Any way he found the missing oil galley plug causing the oil leakage. After he put the engine back in he mentioned to Bill there was excessive play in the crank (15 thou is the number that comes to mind). We told Bill there is no way it should wear in the amount of mileage he did on it and to check it out. I could have done it for him but he lives in another town an hour away and he never came by. Don't know what happened but something wasn't right. Would love to know the story but it sounds like it's going to be sitting the next couple of years.

[Cobber]

I think that everyone needs to take in to account that all gallons are not created equal.......US gallons are smaller than Imperial gallons so there will be a difference in MPG consumption figures depending on which measuring system is being used.

[kstrutt1]

I ran ours everyday for around 15 years on the 8V, economy was around 30 UK mpg, but to be honest it is not the best engine, it's harsh when revved, and none to reliable, in 90, 000 miles I had 3 different engines, (original ran the thrust bearings, second expensive recon blew the head gasket, third was still running when removed. I then fitted a sd1 V8 with lpg, which transformed the car, smooth effortless driving with plenty of punch, on Lpg it does around 20mpg, which works out the cost equivalent of 35mpg on petrol and in 9 years it has not missed a beat. I certainly would never go back to the 4 pot.

[busheytrader]

Back in the day my wedge was my daily driver and its commute was about 10 miles to work and back again. It achieved 22 mpg on the commute and up to 33mpg on the motorway but was fun to drive.

With the V8 it's now my high day and holiday car. It gets around 16 to 20 mpg but has been known to fall to single figures

I wouldn't drive it as an every day car....

Adam

[FI Spyder]

not the best engine, it's harsh when revved, and none to reliable, in 90, 000 miles I had 3 different engines, (original ran the thrust bearings, second expensive recon blew the head gasket, third was still running when removed.

When I first got my TR7 in 2006, I read a blog (I will call it that) of a guy in Los Angeles who got 180,000+ miles from his 8V before it needed an overhaul. He put in a Buick 215 from a junk yard in. At about 20,000 miles on that he broke a valve spring so put in Rover ones, he said they were better quality. The last post he had a total 250,000 miles on the car when he sold it. The last post was 1995. With last post mileage and time he must have used it as a daily driver. With Los Angeles there must have been a lot of stop and go hot weather driving. I expect no less from mine. At 107,000 miles it has been trouble free other than loose battery cable to clamp, and loose alternator belt (after belt replacement 9 years ago). It doesn't burn any oil and I expect to get to the 180,000 miles (if the timing chain tensioner rubber doesn't separate, the only thing I'm worried about).

[Hasbeen]

I don't think the old 8V are all that bad.

I bought my current 7 when it had been used as a mild club level competition toy, then left standing for over 3 years, when the clutch started giving trouble.

It had less than 100 PSI on a compression test on 2 cylinders, the other 2 were about 145 PSI, & one exhaust valve was sticking open about 50 thou, due to rust or carbon on the stem. One valve was also riding.

Expecting to have to rebuild it, & not having the time just then, we decided to have a bit of fun. After fitting a new clutch & adjusting the valve clearance, apart from the sticking one, I did an oil flush then added good oil & STP. We then used it on my private autocross, a one kilometre track slashed around my bottom paddock.

After a couple of hundred kilometres of merciless trashing, it was running much better. I guess we had polished the rust off the bores & elsewhere. The oil was a funny yellow/brown colour. The compression was up to 160 on all pots, & it was producing more power than my "good" 7.

Deciding to put it on the road "as is", I did the brakes, gave the thing a cheap paint job, seat diaphragms, & a fuel tank overhaul, & drove it for 72,000 kilometres with no real problems.

I don't rev past 4000, it does nothing up there, but I love it's torque from about 2400 to 4000. Sure it's a bit harsh between 1500 & 2000 RPM, but you should not be driving at those revs anyway.

I think apart from its weight, it is a great engine for it's day, & believe it would have been developed into a really top engine, if not for the more exotic version in the Sprint attracting all the development.

Compared to things like the BMC B series in the MGs, & the Ferguson tractor engine in the early TRs, & the overgrown 1500cc 4 pot expanded to 6 pot in the later TRs, I think it is by far the best engine ever fitted in a low cost pommy sports car.

It would be pretty easy to get 150 reliable BHP out of one, if really interested. However while it is so easy to just plonk in a Rover, it will probably never happen.

Don't knock it, just enjoy it. Driven sensibly it will reward greatly.

Hasbeen

[kstrutt1]

If I were doing mine again I would be seriuosly tempted to drop 1.8 mx5 engine and box in, 135bhp smooth and as cheap as chips.

[Tamas Petrunin]

I don't think the old 8V are all that bad.
<snip>
I don't rev past 4000, it does nothing up there, but I love it's torque from about 2400 to 4000. Sure it's a bit harsh between 1500 & 2000 RPM, but you should not be driving at those revs anyway.
<snip>
I think apart from its weight, it is a great engine for it's day, & believe it would have been developed into a really top engine, if not for the more exotic version in the Sprint attracting all the development.
<snip>
Don't knock it, just enjoy it. Driven sensibly it will reward greatly.

All good stuff to hear, I have defintley settled on a having an original 2 litre 8V engined car, now all I have to do is find a good one, preferably with a 5 speed box. As this is a classic car, my plan is to stick to how it was "back in the day", so period mods are allowed, and subtle improvements where nessesary that improve reliability and/or driving pleasure without loosing the essence.

A massive thanks to all who have given their opinions.

[Bobbieslandy]

Do you do enough miles for the mpg to be an issue? I had the 2.0 8v, it was great and very torquey. I used to love the 'shove' it had when you crawled in first at idle then planted the throttle, it just took off. The sprint engine is just a warmed up 2.0 8v and not worth converting to, it just doesn't offer anything exceptional apart from novelty value. As a result, i gave the 2.0 8v to a mate, the sprint engine went up for sale and currently have a V8 waiting to go in and to hell with the MPG

[Tamas Petrunin]

Do you do enough miles for the mpg to be an issue?

Hmmm, probably not, it's not like it'll be used everyday and I only average about 6k a year in my main car, and I fully expect to park up a TR7 for the winter to avoid the rubbish weather and all the bl**dy salt they chuck on our roads everytime it gets a little bit chilly. So maybe 2k a year at best, probably less if I'm being honest.

currently have a V8 waiting to go in and to hell with the MPG

That says a lot to me about the merits of the various engines, I went to the local TR drivers club meet for the first time recently, and after chatting with the members there, the consensus was there was hardy any difference between the mpg achieved by their V8's and their 2litre cars. A few members had kept a record of their fuel consumption on some of the longer trips they have done, I was suprised that the V8 had averaged 34mpg including a bit of track driving.

Assuming that is correct (and I have no reason to disagree with their finding) then the V8 is looking like an option again, <sigh> I'm going round in circles here. I really would like a V8 and assuming it can average 30+mpg then it's the prefered option as my only real concern with the V8 was fuel consumption and lets be honest it has a soundtrack to die for.

[busheytrader]

More smiles per mile with a V8 if your annual mileage is low. Bimble along at low revs in 3rd, 4th or 5th with the option of that V8 grunt and torque when you want it.

I converted my own to V8 back in the day and if I can do it then anybody can. It's easier with a "common underbody car". These have the captive nuts in the chassis rails for the TR8 radiator mounts and exhaust hangers on both sides at the back for the twin exhaust system. IIRC all TR7's had these when the drop head was introduced.

Adam

[Shauniedawn]

Don't kid yourself mate - you ain't going to get 30+ mpg out of a V8 [SD1 variant].

At 2k miles PA mpg has almost no impact.

Assuming £4.80 per gallon...

At 30mpg = 67 gallons = £322
At 25mpg = 80 gallons = £384
At 20mpg = 100 gallons = £480

Difference between 20 and 30 mpg PA = £158 PA - is that really worth fretting over?

Fit the engine you want and it'll be worth every penny.

[Tamas Petrunin]

Difference between 20 and 30 mpg PA = £158 PA - is that really worth fretting over?

Put like that, NO ! V8 here I come