Badger
Part of things
Posts: 250
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Sept 5, 2017 18:51:32 GMT
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'Evening all, now that I'm coming to the end of my Haynes Roadster build (I bloody hope) I'm planning to put my Dolomite into the workshop for a ground up rebuild and turn it into my daily. It's currently got a supercharged MX5 engine in it but I'm not overly enamoured with this set up to be honest, so am looking at swapping or tweaking the engine. One definite is an Emerald ECU, and hopefully 2-3 different maps for FI engines (eco/normal/power on). After a fair bit of research I've got a shortlist of three options: - Turbocharge the 1.6 MX5 engine with stock gearbox. Approximately 240bhp maximum. - Swap in a SAAB B234 engine with R28 gearbox. Approximately 400+bhp maximum. - 2.0 Duratec mated with a Mk3 MX5 gearbox, probably keeping it N/A. About 200bhp with TB's and 220 with cams and TB's I've heard. Before anyone makes any other suggestions I've also considered the F20c (too expensive), the Z20LET (not as good as the B234), Jag V6 (not so good on the juice), VAG 1.8t (no rwd gearbox) and the 2ZZ-GE (no rwd gearbox) amongst others. Engine has to be either a 4 pot or V6 to fit within the engine bay with no cutting. From my point of view there's pro's and cons with all three: The MX5 turbo route is well trodden, the engines are robust and all parts are readily available. I've got the engine and gearbox installed (though I want to relocate it slightly to improve access). However it isn't going to set the world on fire in terms of performance or economy. An LSD for the axle is probably still required for safety. The B234 looks like an absolutely insane engine, capable of both high power and good reliability without cracking open the engine. It is, however, the hardest work in all likelihood - the rear axle (a Sprint one) will need to be swapped to an Ovlov\Atlas one to handle the power, and I've heard conflicting reports about the R28's ability to handle power which may necessitate a BMW gearbox and adapter plate. The Duratec is a light and popular engine, capable of making reasonable power. Part of me likes the idea of a tuned N\A engine. Cons are that it's less power, may or may not need an LSD and is probably not too good on the fuel economy. SO... essay finished, I'm hoping you guys can offer me info or experience on this lot to help me make up my mind and generally stop dithering! Because it always helps to see what someone's on about, here's a few pics:    |
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Sept 5, 2017 19:29:47 GMT
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Volvo T4 would be on my list.
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Sept 5, 2017 19:33:14 GMT
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I'm sure you can get a gearbox for the vag1.8t as I'm sure they fit those engine in to the mazda rx8
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Badger
Part of things
Posts: 250
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Sept 5, 2017 20:26:05 GMT
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Thanks for the replies guys.
I did look briefly at the T4 engine (the B5204T4) but the B234/B204 looks better, and it doesn't seem to have a RWD gearbox that bolts up. It is however pretty light, being all aluminium.
Unfortunately there is no gearbox that mates directly to the 1.8t that I could find; the RX8 guys I've seen have used homemade adapter plates (at least I can't seem to find anywhere selling them!).
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ken21
Wales
XR4i
Posts: 35 
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Sept 5, 2017 21:07:30 GMT
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cosworth YB
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Badger
Part of things
Posts: 250
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Sept 5, 2017 22:22:26 GMT
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Find me a runner for under a grand and I'll do it  |
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adam73bgt
Club Retro Rides Member
Posts: 5,004
Club RR Member Number: 58
Member is Online
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Sept 5, 2017 22:38:47 GMT
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I've no idea about how easy they are to fit or not, but I'm sure I remember seeing two Dolomites (Might have been Toledo's) with Nissan CA18DET engines fitted at the Gathering, might be worth seeing if either of them have build threads on here?
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Sept 5, 2017 22:39:26 GMT
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Volvo M90 whiteblock gearbox from a 960 afaik. Edit: ah, ignore this idea, the price seems a bit stupid on these as they are now deemed as "rare".  |
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Last Edit: Sept 5, 2017 22:45:28 GMT by sausage
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Sept 5, 2017 22:58:59 GMT
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I think you can run VAG 1.8T on a quattro box with FWD disabled and locked to get RWD.
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ChasR
RR Helper
motivation
Posts: 10,309
Club RR Member Number: 170
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Sept 5, 2017 23:06:22 GMT
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I was about to mention CA18s like adam73bgt did. They looked well under the bonnets. From my own experience I'd fit a Duratec HE if you can get past the cost and the height issue. In an Escort Mk1 or Mk2 they require some thinking to fit in. The benefits are they are light, mega reliable and as you say produce alot of BHP on stock internals with some well trodden paths; around the 200 mark on throttle bodies and a decent exhaust system. RetroFord also do many bits to make these RWD friendly as well. Ford still use a version of this engine as the basis for the 2.0 EcoBoost as well and I believe that derivative is around in the Focus RS and Mustang. The other issue is that they can be pricey to pick up. In stock form they do around 40MPH+ on a run. The reason why the fuel economy was dire in the Fiesta STs was down to the gearing ; it was very short. If the Jag V6 is anything like the ones in Fords you cannot take any chances with the cooling system otherwise things can get expensive. With that taken care of they are mega reliable to be fair, but lazier than the 2.0 Duratec. The other choice as you say is to turbocharge the MX-5 unit. You know it can take it as well and there are a good few packages out there like the ME221 ECU, manifolds and all sorts to buy for them. Reliability seems to be questionable on turbocharged units. Maybe staying closer to 200 alleviates this  . |
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Last Edit: Sept 7, 2017 12:30:57 GMT by ChasR
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mk2cossie
Club Retro Rides Member
Posts: 3,063
Club RR Member Number: 77
Member is Online
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With the Mazda gearbox already in there, I'd be swayed towards going for the Duratec if it bolts up to the Mazda bellhousing  Pick one up from a breakers would be the cheapest option, or a running Ford or Mazda car with a slightly iffy/short MOT |
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BMW M44 1.9 and gearbox cheap to buy and not that hard to get running 140 bhp
Had many dolimites over the years nice car
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Last Edit: Sept 6, 2017 9:29:52 GMT by mt500ish
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820
South East
Posts: 793
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Sept 6, 2017 13:08:31 GMT
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Why not a Sprint engine? with the work saved in fitting something that is not meant to be in there it would be nice to do a fully rebuilt Triumph engine with Fuel injection, full engine management and a big radiator.
The Sprint engine bay is very small with a low bonnet line, Triumph designed a nice compact 16 valve engine for job.
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ChasR
RR Helper
motivation
Posts: 10,309
Club RR Member Number: 170
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Sept 7, 2017 12:45:40 GMT
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As much as I like the idea of the Sprint engine it is wishful thinking to think that you could get 180BHP+ from a Sprint engine without revving the tits off it which you have to do in stock form anyway so that the car will move with any speed ; hoopsontoast can vouch for that. Good parts like HGs and water pumps especially are drying up albeit there are workarounds. What don't you like about the blown MX-5 engine Badger |
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820
South East
Posts: 793
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Sept 7, 2017 15:34:09 GMT
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As much as I like the idea of the Sprint engine it is wishful thinking to think that you could get 180BHP+ from a Sprint engine without revving the tits off it which you have to do in stock form anyway so that the car will move with any speed ; hoopsontoast can vouch for that. Good parts like HGs and water pumps especially are drying up albeit there are workarounds. What don't you like about the blown MX-5 engine Badger I reckon 160 - 170hp is achievable with fuel injection, COP ignition, fast road cam and a properly mapped ECU without having to go over the standard rev limit or raise the compression. dollysprint.com link |
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ChasR
RR Helper
motivation
Posts: 10,309
Club RR Member Number: 170
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Sept 7, 2017 17:09:38 GMT
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I'll try not to derail too much. Have you ever owned a Dolly Sprint or driven one? You'd still have reliability problems however. Payen as an example no longer make head gaskets for them ; or at least they stopped make them a few years ago when I had one ; others like the Stag world are known for being hit and miss like most old British parts. Water pumps are a weak point too ; new ones don't have hardened gears and on a chain driven jackshaft I don't need to say what the consequences of an iffy gear are. The water pump is driven tangentially off the camshaft. But to be fair you can get Davis Craig EWP motors for around £400 with the controller to circumvent that issue and free up a few horses in the mix . Sure, they are a nice bit of engineering but IMHO there are much better engines out there. If I am honest my 1.6 MX-5 felt not much slower if at all when on full chat and that was with 150k on the clock. My point still stands. In stock form they were not that torquey or even fast unless you went over 5k. I will admit I have some bias and a 'never meet your heroes moment'. People spoke to me as if they would eat hot hatch alive. When I drove one and later owned on one new carbs (all tuned up and balanced FWIW), a rebuilt head, electronic ignition and a Davis Craig EWP it was better but still no match for the 106 GTi at the time with oddly the same weight and the same power figure. The 106 was stock bar a decatted Janspeed exhaust. Rob's Sprint in a similar spec I didn't think was all that fast either. When I first went in one the fastest car I had driven was a 167BHP Pug 306 GTi-6. Most of my cars until a few years ago had ~100BHP. I don't deny that they can't make the power but I do think the power delivery is almost rotary like and with questionable reliability now thanks to a lack of good parts without spending a fortune (a Cometic HG for example). I don't doubt what the website says TBH . As always there is more to power than just a number. I never ever thought I would say that, but I guess turbocharging and large cc's have spoiled me over the years. |
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Last Edit: Sept 7, 2017 17:13:13 GMT by ChasR
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820
South East
Posts: 793
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Sept 7, 2017 18:42:36 GMT
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I know what your saying but a Dolomite Sprint is all about its engine, it is what makes it a Sprint, open the bonnet to see a Japanese or Ford engine I am sure most will be disappointed and the cars value will be higher with a well sorted Triumph 16V.
The key to performance and driveabilty is the Emerald ECU running a properly mapped injection and ignition system, SU's and a distributor are hard work, I have owned one and tuned another with twin 45 webbers and cam, I have been through all the Triumph problems. I tried to fit a Ford 289 in mine.
I also remember spending most of my time looking out of the side windows because they are so tail happy, I would look at fitting a watts linkage or panhard rod as much as a power upgrade.
But despite my preferences the point of this thread is something reliable that starts and drives like a modern so it might not be the best option after all, no matter how well built, it is bound to be a bit more “fussy” than a Japanese engine
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Badger
Part of things
Posts: 250
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Sept 7, 2017 22:14:21 GMT
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Thanks again for all the replies here guys, some interesting stuff! I'll try to cover everyones thoughts. Regarding the CA18DET ( adam73bgt, ChasR) you're right, they look like one of the easiest engines to fit in the Dolly in terms of space and fitment, and the ones at the gathering looked lovely. The reason I've decided to not go down that path is the relative rarity of the engine and some concern about future parts availability. Plus I like being a bit different and rarely follow an easy path! sausage, I did wonder about the quattro conversion but never got round to doing too much research - I guess my main concerns would be the size of the gearbox and the costs to acquire and convert it. It's worth a bit more research I think mk2cossie Unfortunately not that simple - mine's currently got a mk1\2 gearbox and only the mk3 is compatible with the Duratec! mt500ish although it has the benefit of coming with a rwd gearbox, I found the 1.9 to be a bit uninspiring (on paper at least) - they don't seem to offer any more than the MX5 engine already has! ChasR thanks for your thoughts on the Duratec, some interesting info there, I'll have a further mooch. I like the idea of keeping it quite light. I've had some dealings with the AJ30 - that's what's in my Haynes Roadster! As you say they're a rwd version of the 3.0 duratec V6 with some Jag tweaks like VVT. It's not a bad engine but that best MPG it does in the Jag is under 30, though that is in a two tonne monster to be fair. I'm looking forwards to trying it out in something a bit lighter  ChasR and 820, your discussion points basically covered my reasons for not thinking of a sprint engine - plus trying to get hold of one would also be a pain! Besides this car isn't a Sprint; technically it's a 1500tc so originality isn't really an issue  |
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rude
Part of things
Posts: 537
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Sept 7, 2017 22:22:14 GMT
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I've been giving this some thought this afternoon. How about if sprints are all about their engines, you open the bonnet and see...
An electric motor?
Just leaving that out here. Curve ball.
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1986 Haunted BMW E24 635CSi
1999 Povo spec BMW E36 1.8i Touring Work Hack
2001 Petrol annihilating Discovery V8
2000 Jaguar S Type 3.0 V6 ~NEW~
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ChasR
RR Helper
motivation
Posts: 10,309
Club RR Member Number: 170
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Sept 7, 2017 23:03:45 GMT
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Pretty much got my points there really. A few years ago I'd have agreed with you. These days I fancy something working 90% of the time ; maybe I binged on cheap and curse word car for too long and did too much maintenance and repair too soon. Christ, even the M3 of mine had me considering selling it with all of the work it took over Spring! I've been giving this some thought this afternoon. How about if sprints are all about their engines, you open the bonnet and see... An electric motor? Just leaving that out here. Curve ball. I do like that idea! But good electric conversions are not what you'd call cheap. For the power however they are spot on. I have to ask again. What don't you like about the Supercharged MX-5 lump? Is it too slow or just not providing the 'thump' of power that you need like cams or a turbo? |
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