Honda conversion drive shafts angle?

[AbitNutz]

I'm seriously considering moving to a Honda K20 engine. All of the kits seem well sorted but I've read that initially there were many problems with drive shafts breaking. Several have said it was because the Honda engine sits further forward than the Rover lump, causing the drive shafts to be angled too much.

Do any of the kits handle this malady better than the others? Or is it no longer a problem? I'm wondering how the kits differed in where the engine actually sits in the chassis.

I saw a beautiful set of mounts by TTS performance....

Thanks for your time,

[subaqua]

My S1 Exige is 3 years and 15000 miles (12k in 325bhp s/c guise) on a single set of driveshafts... not a single issue. Its an Essex conversion.

I think that the experience the main converters now have under their belts ,means that newer conversions and more recent driveshaft replacements have (mostly) got things under control to the point that I'd not consider it much of an issue. They may not have OE reliability, but then as we all know.... OE reliability is a purely relative concept.

Edited by subaqua on Wednesday 11th September 14:24

[Exige77]

My SC Honda is also a Sincs conversion and running around 360 BHP with no probs at all.

I regularly check the Drive shafts for grease or ballooning boots but nothing.

Drive shafts are 3 years old.

Did 3000 + miles hard driving last week and no probs.

Ex77

[Scuffers]

AbitNutz said:

I'm seriously considering moving to a Honda K20 engine. All of the kits seem well sorted but I've read that initially there were many problems with drive shafts breaking. Several have said it was because the Honda engine sits further forward than the Rover lump, causing the drive shafts to be angled too much.

Do any of the kits handle this malady better than the others? Or is it no longer a problem? I'm wondering how the kits differed in where the engine actually sits in the chassis.

I saw a beautiful set of mounts by TTS performance....

Thanks for your time,

that's actually not that accurate...

the Rover position is about the same in terms of diff position, the difference is that with only ~118-160 hp, the joints don't get loaded up enough to cause a problem.

the first hint of a problem was the Autobytel cars with ~200Hp and slicks, they had to change the shafts/joints out for stronger ones.

then came the K20's, stating with more power than the Rovers left off with, and even with the same bigger CV's the increased power and loads heated up the joints.

ultimately the problem is heat though working angle friction, this was solved with using very high spec grease/paste in the joints, along with better tolerance joints (CV's can be quite variable in spec).

all that said, within a Rover chassis car, the limits of where you can put the engine/box mean that the angles are never going to be ideal.

Looking at your profile, if your looking to use a toyota engined car as the base, this problem disappear as you have way more room to place the engine/box, having done a few, you can get the angles almost to zero.

[Esprit]

Simon,

Does this mean that theoretically if one were to make one's own rear subframe to mount the Honda engine further rearwards (and perhaps canted forward slightly), you could optimise the driveshaft angles? Hypothetical question for curiosity only

[Scuffers]

no, its not the subframe that's the limit, it's the chassis leggs.

[Esprit]

Aah okay, and is it just a size thing? As in if you were to use a smaller blocked engine, the same issues wouldn't present?

[AbitNutz]

Scuffers, That's really good information. It seems that this is a non-issue then. I'm deeply in to Honda K-series building. I'm assembling an engine using a K24 block, using a modified F22C (90.7 stroke)crank, custom rods (.935 journals and length), 87.5 pistons. This would give a 1.77 ratio. Topped with a ported and polished Z3 K20 head and 1mm oversize valves....well, you get the idea. I have no experience or interest in the 2ZZ so this seems to be the best road to travel.

As of now, I'm going with a normally aspirated but later on, with a piston change, I may opt for a supercharger. Has anyone used a Lysholm as opposed to TVS-roots?

I've read everything posted regarding this swap on every board I can find. Just out of curiosity does anyone know Joe McCarthy still around? Not that I want to deal with him, I've just not seen a post from him in years and his sight is gone.

Edited by AbitNutz on Sunday 15th September 13:25

[Scuffers]

Esprit said:

Aah okay, and is it just a size thing? As in if you were to use a smaller blocked engine, the same issues wouldn't present?

not really no, unless you reduce the length of the engine and gearbox dramatically, your still stick with the back of the chassis leggs preventing it moving back.

also, even if you could, you then end up with the weight distribution moving back too, less than a great idea.

Ideally, you want a gearbox with a greater distance from the crankshaft line to the drive-shaft line, which is exactly the opposite of the needs for a FWD package, hence the problem in the first place, although when we did the sequential, it's one of the things we were able to deal with (and in that case we moved the diff line a further 20mm back).

[Esprit]

Good info Simon, thanks.

Seems the only thing for it is to make a new rear subframe and go longitudinal/transaxle

Seriously though, I'd love to have a go in one of your SCHonda/EP Gearboxed thingies... look like a right lark!