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V8 into RX8 ?
macc man - 8/7/13 at 12:29 PM

I am currently contemplating if its viable to shoe horn a V8 engine into a rotory engined RX8.
In the USA they use an LS engine conversion but I am trying to do this on a smaller budget.
Was just wondering if anyone els has contemplated this.

[Edited on 8/7/13 by macc man]

MRLuke - 8/7/13 at 12:38 PM

You've answered your own question there really, yes an LS will fit.

Is there a specific engine you are thinking of? (please dont say RV8).

macc man - 8/7/13 at 12:51 PM

I looked at the lexus v8 but it may be too large to fit. A RV8 is a bit old school and may be too big anyway.
Other options I considered were an Alfa V6 or even Ford Duratec. It seems a shame there are so many RX8 out there with dud engines. We must be able to recycle them with a piston engine variant.

Benzo - 8/7/13 at 12:54 PM

quote:
Originally posted by macc man
I looked at the lexus v8 but it may be too large to fit. A RV8 is a bit old school and may be too big anyway.
Other options I considered were an Alfa V6 or even Ford Duratec. It seems a shame there are so many RX8 out there with dud engines. We must be able to recycle them with a piston engine variant.


by the time you find an Auto Lexus and buy a supra box for it you may as well have paid to have an LS engine fitted.

Im using the BMW M62 540i engine in a triumph at the moment, its proving to be huge, very tall engine.

Id say although it seems like alot i would import an LS from the states with a box.

Smoking Frog - 8/7/13 at 01:08 PM

Yes it does seem a shame when you see bargains like this http://www.ebay.co.uk/itm/271233269097?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649 that we can't come up with an locost alternative to the rotary engine. Maybe the mazda v6 with mx5 gearbox? Would it be up to the job?

macc man - 8/7/13 at 01:12 PM

I thoght about an MX5 turbo engine and box but it may not be enough power to be a worthwhile swap.

nick205 - 8/7/13 at 01:20 PM

Always struck me that Ford could have used the RX8 platform to produce their own RWD coupe.

New Capri maybe?

coozer - 8/7/13 at 01:55 PM

The Ford 302 is a nice small 5L motor.

There was a stand at Stoneliegh this year with an LS and a 302 on display. The 302 was tiny compare to the LS!

Did anyone take any pics of the stand?

Click this for the dims....

http://www.v8church.co.uk/convert_to_v8/which_v8/ford_v8/

[Edited on 8/7/13 by coozer]

GonzoRacer - 8/7/13 at 02:55 PM

quote:
Originally posted by coozer
The Ford 302 is a nice small 5L motor.

There was a stand at Stoneliegh this year with an LS and a 302 on display. The 302 was tiny compare to the LS!


Very true, Sir.
One reason I went with the Ford 302 for my build was that it is a good bit smaller than the GM small-block 350 or 305. It mainly differs in width, with the Ford a clear winner.

Numerous hot-rodders over here (USA) have put the 302 into MX-5s. It fits nicely, even uses a stock bonnet. Requires a beefier diff, usually a Ford 8.8 from a Thunderbird Super Coupe or Mustang Cobra IRS. I don't know of any 302-into-RX8 swaps, but it should be do-able.

While the pushrod 302 is compact, it is a heavy lump, about 450 lbs dressed out. And the later versions, the 4.6 or 5.0 OHC motors are very, very wide, especially the cylinder heads. Fitting any of them into an RX might be a great deal of trouble.

Regards-
JDK

Bare - 8/7/13 at 03:44 PM

Interesting notion.
But Why? oem RX8's inhale fuel !
Likely THE underlying reason these are worthless on resale.
And at the usurious fuel prices inna UK I'd be thinking Moped let alone a thirsty car.
Adding an old tech V8 will only result in even greater fuel costs.

froggy - 8/7/13 at 05:10 PM

I have been making parts for a guy fitting a Saab b234 into an rx8 and the main issue is the bulk of the Mazda steering rack right in the way of most inline engine sumps .
Lexus v8 is a cheap engine but you need a w58 or r154 box plus an adaptor plate and an mr2 turbo flywheel . The later trigger wheel from the Vvt engine means you can bin the stock ecu and run either cop or twin coil packs with an ms or similar .
My mates Saab powered car has been a cheap build but very labour intensive

macc man - 8/7/13 at 06:31 PM

Thanks for the usefull info guys, I was aware the rack may be a sticking point, but like most self build cars no problem is insurmountable with a bit of work.

clairetoo - 8/7/13 at 07:18 PM

The KL V6 into an Rx8 is something I've thought about - the rack position shouldnt be a problem , the Mx5 is similar and can be worked-around quite easily .

froggy - 8/7/13 at 07:40 PM

Not being particularly light I'd think anything less than 250 hp isn't worth the effort .

jon200 - 8/7/13 at 08:08 PM

Why not just put a Nissan SR20 in one? Pretty light and easily tunable

Grimsdale - 9/7/13 at 07:53 AM

pinto?

dave_424 - 9/7/13 at 08:31 AM

I don't know about engine orientation, but the VW R32 engine is a pretty good engine, or something like a turbo VR6, they make great power.

MikeRJ - 9/7/13 at 11:59 AM

I doubt any modern V8 (or even V6) engine with overhead cams is going to fit without major work. The LS engines are used because they are a pushrod engine and very compact for their capacity/power.

MK9R - 9/7/13 at 12:42 PM

I wonder if a Subaru boxer would fit, its low but wide

Simon - 9/7/13 at 08:26 PM

Diesel

ATB

Simon

Volvorsport - 9/7/13 at 08:57 PM

5 cylinder volvo

PhillipM - 10/7/13 at 12:09 AM

Just slap an MX-5 engine in with a charger kit, anything else will cost so much money to stick in that you may as well just have the rotary motor rebuilt.

rdodger - 13/7/13 at 09:08 PM

quote:
Originally posted by macc man
I am currently contemplating if its viable to shoe horn a V8 engine into a rotory engined RX8.
In the USA they use an LS engine conversion but I am trying to do this on a smaller budget.
Was just wondering if anyone els has contemplated this.

[Edited on 8/7/13 by macc man]


I can put you in touch with engineer who has the parts available to do this if you are interested?

Radiogareth - 24/7/13 at 11:14 AM



I can put you in touch with engineer who has the parts available to do this if you are interested?


Yes please, I've been planning this one for a while and have a nice all-alloy L33 LS (already upgraded) ready to drop in.

Thanks!

Gareth

fastfu - 1/9/13 at 10:42 PM

Sorry to bump an old thread but im just about to go down this route.

Im planning on fitting a 2.3 duratec with throttle bodies and a turbo, the mk3 mx5 uses a duratec (well mazdas version) and ive been told by a mate who works for mazda that the floor pan of the mx5 is the same as the rx8 and the mx5 front subframe fits the rx8, so it should be quite straight forward to fit the duratec in

KFC - 14/10/13 at 10:35 PM

quote:
Originally posted by clairetoo
The KL V6 into an Rx8 is something I've thought about - the rack position shouldnt be a problem , the Mx5 is similar and can be worked-around quite easily .


Hi Claire, yeah there are a lot of good RX8's out there with dead engines. I don't have time to build a kit car but like the idea of the V6 in a RX8. Cheap to buy and get an engine out of a mondeo or S-type. I'm driving a MX6 with the 2.5L klde engine but I thought a AJ30 would be better for the engine lay out with a lot if usable parts, manifolds, mounts, bolt on the RX8 bellhousing? I'm not sure but I thought the rwd version with the duratec based engine would be ideal. I would like to try and use the stock inlet and ecu just to keep the cost down. What do you think?

Craigorypeck - 15/11/13 at 02:16 AM

how would a cossy YB fit in an RX8 with a t5 box?? has it been done? looking for a new project.. . . .