Big Bore LC Barrels - 392cc and 421cc

[muttsnuts]

ok, so another of my projects is the big bore LC barrel, I've been doing some research etc in the background and finally got some numbers to work with

Now it is not trivial by any means and so I am going to have to think about this really hard.

The numbers involved are staggering, but basically I need to have a minimum of 350 sets(pairs) made, these would be 68mm cylinders (ceramic coated), so giving you a 392cc LC or with a 4mm stroker crank 421cc, the barrels would look stock, they would have YPVS reed cages capability, so better breathing and improved porting (without being stupid), now in stock 392cc trim you would get around 65bhp to 70bhp (same as an Athena kit), although I can't be exact as I've not been in a position to test my only prototype set, ormport them exactly the same

I'd expect a 421cc to push around the 70bhp to 75bhp minimum, again, hard to say at this moment as there is still work to be done, but my 421cc protptype is pushing 70bhp with huge torque (42ftlb's) all at 9k rpm, so no stupid rev's and very basic porting

Price wise, I think they would market at around the same as an Athena kit for the YPVS, so £800 to £850 for a pair of barrels with piston kits, but the head would still need modifying to suit, say another £100, but I am looking into options on having some cylinder heads made to suit

So the big question for everyone is, do people think there would be a market for such a quantity, its all ok having 20 people saying yes, but that would leave me with 330 pairs of barrels and a huge hole in my bank balance !

thoughts peeps..........

[donkeychomp]

Personally I'd love a set but I can't see you shifting 350 of them Dave. At the best you'd sell maybe 50 or so very quickly then the rest will go eventually...perhaps. Unless you plan on selling them worldwide? In that case you'll probably sell the lot.

Alex

[muttsnuts]

I think I'd have to do worldwide etc, I am still in various discussions, but getting the quantity down to a manageable amount is hard, plus I need to find the sweet spot for the price break, its ok getting 350 pairs made at a good price, but how much extra is to have only 100 pairs made (assuming they would do that little), it might work out £100 a set more, but then significantly less risk on me not selling the lot, plus of course the space required to store such a quantity isn't exactly insignificant either, and of course 200 pistons !

I am not giving up on it yet, on the plus side, I've made better progress on the 4mm cranks for the LC, just waiting on a prototype being sent to me for checking/testing etc

[donkeychomp]

Well, as I mentioned Dave, I am keen. Keep me posted!

Alex

[rigga]

I'm interested, question is how many other LC owners would be. No other options out there, everything is pv or banshee based, so it's a very welcome option should it come to fruition.

Cost to you obviously is a consideration, especially with the proposed numbers involved .

[veg]

This is where you would need international distributors? Or at least the ability to market in say Japan. Is there a worldwide demand ? I’d say yes think of the Japanese and other markets on top of the Uk. I’d deffo be interested, however this forum is a ltd site, have you dipped your toe in the club? FB? What other markets are there apart from those mentioned?

[JonW]

Its a great project Dave and something the LC lacks when the YPVS has gained so many engine upgrades from the banhsee aftermarket.

Its a big investment tho, totally get that. Same happened when the tanks were made, huge boxes needed to be stored as well, at least with these thats less of a hassle.

Its great that youre thinking about actively working on this stuff, keen to see what you decide.

[elsiefan]

I like the idea of a stealth upgrade for the LC; looky likey barrels and heads are a great idea and I would be interested, though maybe not for a while as I have just rebuilt my lump. What are the potential lead times to getting production versions for sale, in your possession? All things being equal, and bearing in mind all the other issues you have to consider for such a project, not least of which is the capital outlay on your part.

[nakedgoose]

I share a pretty similar situation to elsiefan, as im just rebuilding my engine now but it would certainly be great to have the option for a big bore kit for the next time a rebuild comes around,

any clue what sort of impact this would have on crank lifespan?

[beardy]

Definitely interested 👍🏻
If they can be run with standard carbs and oil pump? Then I see it as a no brainier compared to the cost of re lining old barrels and associated costs. Also to get that sort of power out of an lc I’d need to get a pv motor just to begin the project.

[masonmart]

I would say that as the YPVS moves into the classic phase that there will be less and less people who want to do performance enhancing mods as they would when the bikes were regularly used in anger? To be fair it's also not a massive increase in power from the standard bike, the extra torque may make the ride a little nicer but who needs extra speed in this day and age? I doubt that you have the business case to make that many and recover your money but how about a costing to make on demand?

[rigga]

Apr 28, 2023 10:22:17 GMT 1 masonmart said:

I would say that as the YPVS moves into the classic phase that there will be less and less people who want to do performance enhancing mods as they would when the bikes were regularly used in anger? To be fair it's also not a massive increase in power from the standard bike, the extra torque may make the ride a little nicer but who needs extra speed in this day and age? I doubt that you have the business case to make that many and recover your money but how about a costing to make on demand?

This is for LC engines and not ypvs, those have a huge performance industry that caters for those engines , with banshee performance tuning, the LC pretty well has nothing.
I'd say going from low 40's to 70 odd brake is a pretty big jump in performance.

There has always been two sections of LC owners, those that mod and those that like original.
Back in the day I can't recall anyone not modding their bikes , and I'm still the same today, look in the resto section, and there are some incredibly modified bikes , numbers are the only issue with this, not the desire to do it.

[masonmart]

Ah, OK.

[JonW]

Plenty of us still modding YPVS and will continue to do so, said it before (so has Rigga above) but these bikes are not like lots of others, they were modded from new and its a way of life with them.

I do wonder if the desire to buy a restored 'unmolested' one is sometimes just so the next owner can mod it 'from new' spec like they did when they were young...

Ive built (and am building) both modded and nut n bolt restos and the latter is really hard to do considering the parts available now.

Anyway, this is not about the PV bikes, its about the good ole LC which defo does lack a big cc option.

[midlifecrisisrd]

I think you are missing a marketing trick

All this time people have been taking an LC, fitting a ypvs bottom end and a big bore banshee top end

You should now be persuading banshee owners to fit an LC bottom end and a big bore LC top end 🤣

Steve

[JonW]

Steve has a good point... we could be getting ypvs bottom ends out of LCs lol

Dont these cyls also fit the LC cases Dave?

[midlifecrisisrd]

Apr 28, 2023 14:15:16 GMT 1 JonW said:

Steve has a good point... we could be getting ypvs bottom ends out of LCs lol

Dont these cyls also fit the LC cases Dave?

I assumed they were only for LC cases

Steve

[masonmart]

Apr 28, 2023 13:59:32 GMT 1 JonW said:

Plenty of us still modding YPVS and will continue to do so, said it before (so has Rigga above) but these bikes are not like lots of others, they were modded from new and its a way of life with them.

I do wonder if the desire to buy a restored 'unmolested' one is sometimes just so the next owner can mod it 'from new' spec like they did when they were young...

Ive built (and am building) both modded and nut n bolt restos and the latter is really hard to do considering the parts available now.

Anyway, this is not about the PV bikes, its about the good ole LC which defo does lack a big cc option.

Jon, it's because they want a standard bike, that is because the standard bike is exactly what they want. Seems a difficult concept for some to grasp and it's nothing really to do with re-sale although that is worth bringing into the equation. I'm the opposite to some of you, I can't really understand why some feel necessary to modify bikes unless it is to change function such as make it a track bike. Of course it is up to the owner what he does including keeping the bike standard. For me the standard LCs are fabulous bikes as they are.

[veg]

You’re coming at it as a first time owner who has been bitten and who only owns std bikes masonmart. These bikes back in the day were a liberation for the owners and the vast majority were modified, some weren’t but most were. In the same way my dad bought a 1960 bonneville and started to change it immediately. Today the market is slightly different and a fair few people believe that if they are going to invest in one it will be mainly std to recoup the costs.
Then there are those like myself who have pretty much owned an Lc for 30 plus years and have always modified them. My current bike is about as far from std as you can get.
There is absolutely room for all, and as has been said above it is probably one of the most modified range of bikes you’ll ever come across.
Coupled with the passion and long standing relationships these bikes entertain.

[masonmart]

Apr 28, 2023 17:56:26 GMT 1 veg said:

You’re coming at it as a first time owner who has been bitten and who only owns std bikes masonmart. These bikes back in the day were a liberation for the owners and the vast majority were modified, some weren’t but most were. In the same way my dad bought a 1960 bonneville and started to change it immediately. Today the market is slightly different and a fair few people believe that if they are going to invest in one it will be mainly std to recoup the costs.
Then there are those like myself who have pretty much owned an Lc for 30 plus years and have always modified them. My current bike is about as far from std as you can get.
There is absolutely room for all, and as has been said above it is probably one of the most modified range of bikes you’ll ever come across.
Coupled with the passion and long standing relationships these bikes entertain.

Veg, I have incredible satisfaction building and using standard bikes. I have a 1968 Bonneville and changed nothing on it from standard other than fitting a 5 speed box which improved it massively. I buy bikes that in general need no improvement and where it can be improved I improve it. You should see me as a conservationist rather than as a destroyer of that which needs to be conserved. The efforts of you and others is to modify already superb bikes, mine is to restore those bikes from dreadful conditions. I really hope that you don't criticise my right to restore and conserve these wonderful bikes?

[muttsnuts]

Thanks guys, everything mentioned above is appreciated

Having spoken a bit more today, its likely that it would take 1+year to get sorted, alot of too-ing and fro-ing with drawings etc, etc before anything is made, more over I need to stump up half the total cost of the job upfront, that's a major chunk of change (around £50k to £60k) bearing in mind this is only for the castings to be made, then I've got all the machining to sort, ceramic coating and of course pistons (700 in total) !

I've not shelved the idea, but its a big thing for me to consider, this is basically all of my pension fundbeing sunk into this if I go ahead and lots could go wrong !

Of course I am still actively looking for an alternative, ideally what I need to find is a small company/one man band that can do this, but in small batches, the snag is, these days very few companies/people exist who can make the patterns etc and are interested enough to do small runs like 50 at a time......... but I'll keep looking, its far from dead at the moment !

[midlifecrisisrd]

Maybe a daft suggestion but could they be machined out of billet instead of cast?

Maybe make it more viable in smaller numbers

Steve

[muttsnuts]

Apr 28, 2023 18:19:15 GMT 1 midlifecrisisrd said:

Maybe a daft suggestion but could they be machined out of billet instead of cast?

Maybe make it more viable in smaller numbers

Steve

again, its finding a company that could/would do it, plus billet wouldn't give you the "as stock" look, also not sure if it would be possible to machine the transfer port areas, think it would have to be a pretty good machine and a very good operator to program that !

[veg]

Apr 28, 2023 18:14:45 GMT 1 masonmart said:

Apr 28, 2023 17:56:26 GMT 1 veg said:

You’re coming at it as a first time owner who has been bitten and who only owns std bikes masonmart. These bikes back in the day were a liberation for the owners and the vast majority were modified, some weren’t but most were. In the same way my dad bought a 1960 bonneville and started to change it immediately. Today the market is slightly different and a fair few people believe that if they are going to invest in one it will be mainly std to recoup the costs.
Then there are those like myself who have pretty much owned an Lc for 30 plus years and have always modified them. My current bike is about as far from std as you can get.
There is absolutely room for all, and as has been said above it is probably one of the most modified range of bikes you’ll ever come across.
Coupled with the passion and long standing relationships these bikes entertain.

Veg, I have incredible satisfaction building and using standard bikes. I have a 1968 Bonneville and changed nothing on it from standard other than fitting a 5 speed box which improved it massively. I buy bikes that in general need no improvement and where it can be improved I improve it. You should see me as a conservationist rather than as a destroyer of that which needs to be conserved. The efforts of you and others is to modify already superb bikes, mine is to restore those bikes from dreadful conditions. I really hope that you don't criticise my right to restore and conserve these wonderful bikes?

The ‘There is room for all’ statement should show my thoughts. I give not a tuppenny toss what others do with their bikes.

[veg]

Anyway back on track 😳
It’s a gigantic undertaking Dave with no guarantees sadly, whilst I understand it’s not totally an altruistic approach it’s appreciated what you already do to help keep us on the road. 👍

[jackjabba]

I would be making contact with the guy in Malaysia who sells all the NOS RD parts to see if you could get him on board with selling them.

I would be interested in a set, but that leaves you stuck with a lot of spares.

[masonmart]

Apr 28, 2023 18:39:49 GMT 1 veg said:

Apr 28, 2023 18:14:45 GMT 1 masonmart said:

Veg, I have incredible satisfaction building and using standard bikes. I have a 1968 Bonneville and changed nothing on it from standard other than fitting a 5 speed box which improved it massively. I buy bikes that in general need no improvement and where it can be improved I improve it. You should see me as a conservationist rather than as a destroyer of that which needs to be conserved. The efforts of you and others is to modify already superb bikes, mine is to restore those bikes from dreadful conditions. I really hope that you don't criticise my right to restore and conserve these wonderful bikes?

The ‘There is room for all’ statement should show my thoughts. I give not a tuppenny toss what others do with their bikes.

Then you must apply that to me. Thanks.

[rigga]

Would the likes of Norbo and other LC vendors be interested in a collaboration?
Be a way of spreading the costs and they would then be in a position to retail the finished items as well as yourself?

Just thinking of ways to mitigate the financial costs to one individual considering the outlay involved.

[JonW]

Apr 28, 2023 18:16:33 GMT 1 muttsnuts said:

Thanks guys, everything mentioned above is appreciated

Having spoken a bit more today, its likely that it would take 1+year to get sorted, alot of too-ing and fro-ing with drawings etc, etc before anything is made, more over I need to stump up half the total cost of the job upfront, that's a major chunk of change (around £50k to £60k) bearing in mind this is only for the castings to be made, then I've got all the machining to sort, ceramic coating and of course pistons (700 in total) !

I've not shelved the idea, but its a big thing for me to consider, this is basically all of my pension fundbeing sunk into this if I go ahead and lots could go wrong !

Of course I am still actively looking for an alternative, ideally what I need to find is a small company/one man band that can do this, but in small batches, the snag is, these days very few companies/people exist who can make the patterns etc and are interested enough to do small runs like 50 at a time......... but I'll keep looking, its far from dead at the moment !

Dave, I wonder if its possible to find out who made the repro cyls that Webike are now selling? Im not 100% but they were probably sourced by someone large like Daytona / Mizuno etc?

If you could find the actual maker of those you would be most of the way there as they a, have the moulds, b, have the technology to coat the cyls.

Getting the bigger bore would be a relatively simple change, the porting would take more work and the integration of the larger reed cage would be a bigger change.... but it would be a good start as its already been tested and they sell these units to customers already.

Food for thought...

[tsa]

What we need also is a BB YPVS kit now they would sell Im sure. Make them triple port with PV controlled aux ports too. 392cc 90bhp sounds interesting