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Nb Rs Rocketeer V6 Conversion

20K views 63 replies 18 participants last post by  smiffy415  
#1 ·
There's no 2 ways about it, I have a smokey mk2. It's been breathing a bit heavy and using oil since I bought it in late 2014 and it's taken this long to decide what to do about it. Don't get me wrong it doesn't stop me from tracking the car as it still goes well for a standardish mx5 - but as a mechanic it's becoming embarrassing.
So I weighed up the options; supercharger, turbo, blink motorsport high comp/cams/itbs etc. I wanted another 100bhp/100lb/ft to allow the car to be competitive on the bigger tracks so i did the maths.
Supercharging is the sensible option but I did struggle to find kits for sale and one that fitted the bill.
Turbocharging is the easy way to extract power but I'm not convinced on the cost of building a reliable a 250bhp motor. Plus I've had high power turbocharged cars and worrying about service intervals, boost leaks, temps on track etc put me off from going that route again.
Running the standard lump in higher compression trim with a camtrain/head/induction overhaul did appeal to me - but, I don't want to run a peaky race esque engine which would probably ruin the car when driven on the roads.
Last year a family kept banging on about an off the shelf V6 conversion that was gaining popularity but I'll be honest it didn't appeal so I ignored him. It sounded like the sort of thing a middle aged bloke would do and then drive it slowly to shows/meets pop the bonnet and talk about. About 12 months passed and I gave in and had a look at the website. Mmmmm, I was surprised at the professional and technical look of the site with its technical drawings and images of the v6 and subframe assembly. I looked at every page, read everything the site had to offer and it definitely intrigued me, the kit looks very comprehensive and well thought out to be a plug and play job.
But then I saw the price! F**k me ÂŁ7200! What! There's no way I could justify that, the car owes me about ÂŁ3500 currently with gaz pros, roll bar, brake upgrades etc. How on earth can an engineless kit cost that much?
So I sacked the idea off and went back to thinking about what to do for another 6 months. In that time my savings grew and I got itchy feet. Sod it I'll turbo it on the cheap and have some fun. 200bhp is easy and should scratch the itch without over stressing anything so I priced it up. By the time I'd factored in a refresh of the engine, turbo/manifold/downpipe and exhaust system, clutch, management/mapping, wideband, pipework, boost control etc. You're already talking ÂŁ4-5k to buy new parts and do things properly and deep down I didn't want turbo power again.

So I dropped Rocketeer an email regarding cost, delivery dates, possibility of driving the demo car and i got a quick reply. Bruce was very helpful, enthusiastic and forthcoming. So we organised to meet for a chat so I could have a look around the car, ask questions, checkout the conversion parts in the flesh and most importantly drive the thing. After all I'm not about spend ÂŁ7k on something I might not even like the feel of when behind the wheel. Bruce is a top bloke, he answered every question technical or general and didn't push the sale of a kit at all. The car impressed in the flesh, the parts list included in the kit is vast. You name it, its included in the kit. At the point of being handed the key for a test drive I still didn't want to like it (daft I know, but don't ask me why) but I didn't know what to expect either. The car started, idled and drove like a normal mazda with a bit more noise. When you keep the throttle pinned up towards the red line it changes completely, the car goes from feeling a normal under powered low comp 4 cylinder mx5 to a rev happy, very powerful sports car. Woah... I didn't expect it to feel that crisp. I've driven plenty of 3 litre S types and they shift but in the same way a sofa shifts if you push it down a waterslide. This was different, it just felt right and worked perfectly in the mazda chassis (although I must say I think it will work better with a 6 speed box, sorry Bruce) I had to have it.
So that was it, I took the plunge and paid Bruce a deposit. Hopefully I'll take delivery of the kit in the next 2-3 weeks so I had to get my arse in gear and get a donor engine ready. I had been in talks with a work friend since January about his s type so I called and "talk to me" 2 weeks on and here we are.
Last night we had a late one, I got the beer in, pulled the doors down and cracked on pulling the lump out of the jag. Anyway, enough of me banging on I'll let the pics do the talking.
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#4 ·
So I've been into the workshop this morning to transfer the engine to a stand and had a few hours stripping the unwanted ancillaries off the v6 to see what we're working with. It's a very compact lump and is packaged nicely (I can't wait to bin the hideous sump). The next step is to wait for a delivery date for the kit so I can strip the mazda engine and subframe off the car ready.
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#11 ·
From what I understood it weighed some 20kilos more but as it's a shorter block more of that weight is behind the front shocks.
What Jam said. Bruce told me that stripped of ancillaries there was very little in the difference in weight between the 2 engines. Driving it feels no different in terms of weight distribution and balance to the cars road manners.

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#15 ·
Right then, since the last post all I've done is have the cam covers powder coated and changed all of the top end seals.

After longer than expected delays for a few parts of the kit to be manufactured I got impatient. This morning I went down to coolest the kit from Bruce in person (just waiting for the flywheels from the US).

The kit is a lot bigger and more comprehensive than even I expected, its nice to see all the attention to detail and quality of manufacturing, even the nice stainless fasteners. I can finally get cracking now and hope to have made some significant progress in a months time. Anyway, some pics. Watch this space.
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#17 ·
#18 ·
So today works been a bit slack in the workshop so I thought sod it and made a start. Got the old 4 pot completely out ready for a quick spruce up of the engine bay.
My next job is to dress the engine and replace as many external seals and gaskets and possible along the way.

The next step after that is to remove the existing subframe and build up the new onr complete with suspension/engine and box. I will need the flywheel here before I can do that so for now here's a few pics.
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#20 · (Edited by Moderator)
Had a couple of hours this afternoon so I 3 managed to swap over sump, gasket, baffle, oil pick up pipe and front crank oil seal ( the front pulley put up a fight as there was silicone between it and the nose of the crank on the key way for some reason). The sump is a lovely cast item.
Pics for comparison.
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#23 ·
I was at a trackday at Thruxton last year and parked next to Westfield with a Jag V6 engine..they lost the engine in the afternoon due to big end going..i suspect oil starvation.
If going on track with this i would look into a baffled sump on accusump...
No idea though what sump was fitted to tge westfield v6 jag though so no scaremongering just suggesting from someone whose on 3rd engine in my track Westy due to oil surge/ starvation.
This is gonna sound awesome...i love the sound of a v6.

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#24 ·
I was at a trackday at Thruxton last year and parked next to Westfield with a Jag V6 engine..they lost the engine in the afternoon due to big end going..i suspect oil starvation.
If going on track with this i would look into a baffled sump on accusump...
No idea though what sump was fitted to tge westfield v6 jag though so no scaremongering just suggesting from someone whose on 3rd engine in my track Westy due to oil surge/ starvation.
This is gonna sound awesome...i love the sound of a v6.

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I did think that to be far but there's a couple using them in race cars already so we'll see how it goes. I'll be using a remote oil filter housing and a 16 row oil cooler so there's gonna be plenty of oil about.

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#25 · (Edited by Moderator)
It's been a pretty productive week as I'm hoping to get the old subframe off, suspension swapped over and new subframe on with engine tomorrow night/Saturday morning. I'm waiting on some new mazda speed engine mounts from moss so fingers crossed they turn up tomorrow ????.
The engine bay has had a quick degrease and clean, removed the old clutch line and replaced with the new braided HEL line, removed the charcoal canister system and tidier unnecessary wiring.
I've dressed the engine as much as possible in preparation for fitting: headers, alternator, pas pump, engine mounting brackets, icv system, throttle body's adapted and fastened to the inlets with support and cable brackets.
After watching the cock ups on the car throttle video I've also completed the necessary mods to the gearbox which include spacing the clutch fork pivot point position, drilling the bellhousing for starter clearance and chamfered the bellhousing around its circumference to avoid any potential flywheel fouling. The ecu is mounted properly with the supplied rubber bobbins and rivnuts (which weren't in the kit for some reason). I'm not sure how I feel about how they've riveted the ecu solid to the bulkhead, surely the vibrations can't be good for it and also lack of airflow behind the unit for cooling. I'll let the pics do the talking [emoji106]
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