Defector from the Aircooled RD forum, building LC/AC hybrid

[angelgrinder]

Hi chaps, My name's Nino (Italian ancestry).
I've always been an aircooled fan (bought a YDS7 in 1979 and still have it, although it's been off the road since 1980!!)

Anyway, I always fancied an LC. Trouble is, I like the engines more than the chassis. I've never been a fan of monoshocks (although I did once convert an RD400, using an LC rear end. Looking back, it was pointless other than the [low level] engineering challenge).

So....I bought a stripped 350LC engine and I'd like to stick it in an aircooled chassis.
I'm thinking of building the engine into 250E cases, as they should take the LC crank and generator/ignition without any mods. Is that correct? Have you any advice on this? Thanks in advance.

The major drawback is the lack of water pump drive so I'm considering an electric pump as I've seen on at least one LC (in fact, the property of the chap I bought the engine from). I think he said he's on this forum but I can't remember his name now. I guess we'll bump into each other soon enough anyway.

Does anyone have a link for a suitable electric water pump? Or is there a mechanical alternative? I won't be using the oil pump so maybe a TZ pump off the oil pump drive? Anyone done that? (I tried it in 1980 with a TZ top end on a 350B motor but it was a bit of a bodge).

Any advice will be gratefully received. Thank you.

[botty]

Welcome to the Forum Nino.

I have done a similar conversion using a YPVS engine.

For some reason I had to alter the rear engine frame mounts. I had been told LC engines would fit straight in as it had been done before.So took it for granted mine would.

Fitting the LC lump would make things a lot simpler, however it is your choice.

Good luck and get some pictures up.

You also mention about the tie bars.

I cut out some channels and welded in some half pipe

[angelgrinder]

Cheers Botty, what did you do about the tie bars? Did you use them?

[botty]

Yes I used them.

Its got a build thread on the aircooled and 2strokeforum.

[angelgrinder]

Found your thread on the AC forum....fascinating!

All that DVLA stuff was a total bummer. Thankfully, my frame is already registered to me with a V5. It seems they only exist to make life difficult for honest special buiders.

Love the tie bar fix. I think I will stick with the LC cases now.

Pics will follow but not soon. It's abox of bits and a standard frame at the moment. I have a whole lot of stuff to sort out before I can even put them in the same place, let alone call that a workshop!

[dusty350]

Hi Nino
Welcome to the forum mate. Had a 400 monoshock myself in the past, 2 in fact, but would prefer twin piggyback shocks on an aircooled now. The Tz style pump off the oil pump drive has been done before. This is from the late 80's at Santa Pod. The lad said it was a Fahron conversion;



Enjoy the forum mate.

Regards

Dusty

[dusty350]

Oh and this one is far more recent;



Dusty

[angelgrinder]

Thanks Dusty,

I like your bike and I noticed your useful input on Tony's build thread.

It's always good to throw some ideas out and get feedback from people with hands-on experience. I'm already honing down the possible permutations of engine internals/cases, frame mods, suspension type after just a few posts on two threads.

So it's going to be LC internals in standard cases, frame altered for tie bars, twin shock rear end (probably a PV arm, which I already have, with shock stirrups welded on).
I have a couple of PV front ends too so would be a logical choice.

As for wheels, I don't want to go too wide but I do want tubeless so I'm thinking of using a pair of Honda CB350S-G wheels which I have lying around (2.15-18 front and 2.5-18 rear, I think). That would keep a drum rear end (another of my eccentric preferences).

To go a little wider, I also have a pair of ER5 wheels (a bit more modern looking and 2.5-17/3.5-17, still drum rear).

[dusty350]

Hi Nino,
So am I right in thinking you are going to transfer the Lc internals, barrels etc into aircooled cases ? I have no experience of that but I would check the obvious things like stud pattern first. I would have thought the crank case layout would have been close enough for you to use the Lc cases. It has been done the other way round too;



The pv front end bolts straight into the aircooled headstock. The Ypvs swingarm is wider at the frame mount than an aircooled or Lc swingarm, so you will need that milled down a bit. Chain run will need to be sorted too. 17" wheels will give you better tyre choice as well. A Tzr rear wheel fits fairly easily into the pv swingarm but is obviously disc brake so may not suit you. Modern 3 spokes tend to be a lot lighter than standard 70/80's wheel so you can save a lot of weight using modern wheels. Also worth mentioning there are other front ends that fit easily if you want even more modern/upside down style, such as Rgv/ Tzr125/ Zxr/Fzr. I have a Tzr 125 Belgarda front end in my F2, and it fits with just a 5mm spacer under the bottom bearing. Food for thought

Dusty

[steeley]

Nino hi,welcome to the forum and get some pics up of your build when its started.regarding the ypvs front end I did this on a rd250e some years ago I also put another disc on the front ott I know but it worked out ok.ypvs stanchions are longer and even with them up through the top yolk both wheels touched the ground when on the main stand.since I have found one of the stanchions is bent so needs rolling and I have thought about having them shortened .

[botty]

I would stick with the full LC engine. Makes things a whole lot easier.

Dusty and his builds have been very inspirational and helpful.

We seem to have the same "vision" in what we want.

Lots of members will bounce ideas off you throughout your build. Very helpful. Sometimes you don't see the wood for the trees. Then once it is pointed out. It's so obvious.

Get the pictures up.

[angelgrinder]

Thanks again guys. I'm going to stick with the LC engine in it's own LC cases, now that I've seen that it can be done with minimum fuss and even retaining the tie bars.

At the moment, most of the parts are in a lock-up some miles from my home and my back garden workshop needs a solid week's work to make it useable. That's going to have to be a week some time in the spring as it's not worth wasting a week off work just to get rained on and frozen with darkness closing in by 4:30.

Once that's done, I'll be able to escape the family TV dinner scene and make some progress on the projects (yes that is a plural you see there; there's a couple or five other bikes waiting for my attention as well).

Once I get the parts in one place, I'll get some photos done and start a build thread. I can see I won't need to get embarrassed about taking a year or three over it.

[botty]

Too right. Mine took 4 years and some months to finish.

Mind you it did go on the back burner a couple of times, while I did other bikes.

It's all worth it in the end.

[muttsnuts]

unless you have some access to some good engineering equipment then I'd stick with the LC engine, I've created a 400LC engine based on using an RD400F crank cases/bottom end and some 350Lc barrels etc and beleive me, it wasn't straight forward, if you get chance check out my current build thread for my turbo 2 stroke as that is the engine I built - then decided to turbo charge - I am not suggesting you try that though !

[angelgrinder]

Dec 23, 2014 20:20:18 GMT 1 muttsnuts said:

unless you have some access to some good engineering equipment then I'd stick with the LC engine, I've created a 400LC engine based on using an RD400F crank cases/bottom end and some 350Lc barrels etc and beleive me, it wasn't straight forward, if you get chance check out my current build thread for my turbo 2 stroke as that is the engine I built - then decided to turbo charge - I am not suggesting you try that though !

No, re-sleeving and all that goes with the 400LC creation is pushing the envelope too far for me. Besides which I've never really got on with the 400 long stroke engine, even with the rubber mounts, I find it too vibey and not happy at high revs.

Also, I think the air cooled 400 was insufficiently cooled considering the increase in power and higher piston speed due to longer stroke, so I can see why you'd build a liquid cooled one and my hat's off to you on the engineering front.

Basically, my 400 and everyone else's that I knew, seized with incredible regularity so I'll stick with the 350 for the forseeable.

I might go to 375 as and when bore damage/wear demands it but I'll certainly stick with the 54mm stroke.

Having read Tony's build thread, I'm now confident that the LC engine in it's own original cases will be the best bet. Still needs to be rebuilt though! (all good fun).

[dusty350]

Hi
An Rd400 seizing ! surely not .
Mine let go at 95mph in the fast lane of the M25, coming back from Box Hill with the girlfriend at the time on the back This was the result;



The piston on the left is standard 400 for reference. The middle and right pistons were my Stan Stephens modded ones that went pop.
Good move with the Lc engine, it will save loads of hassle and cost. Plus if you can get the Lc engine to fit, you can always transplant a powervalve at a later date

Dusty

[Norbo]

welcome to the forum . I think youll fined the lc a far better bike to ride then the old A/C

[angelgrinder]

It will be an interesting departure. I've never ridden one of the original LCs. I had a couple of brief goes on a YPVS F2 back in the eighties but that was virtually brand new at the time so it would be hard to beat with what I can cobble together now.

That said, newer isn't always better; I'm not nearly as keen on my current BMW 1100 oilhead as the old airheads and my favourite of the Gixxer family was the early oil cooled variety.

Of course this won't be much like any of the standard models so only time will tell...