Board index Flathead Power-Technical Questions, Answers, and Suggestions 45 Flatties Cams....

Cams....

Post Wed Nov 04, 2015 4:00 am

Posts: 1730
I'm just returning to an engine build I started a long time ago, which was shelved due to other projects.

Cams were an unresolved issue. I have never found any UK based engine builder who will attempt the fitting of the Enfield racing units, and I've been around vintage racing long enough to know most of the builders I'm prepared to pay money to. (Please don't reply with long posts about doing this, there's a thread with all that somewhere. I don't have the tools, don't know anyone who will do it, and that's that - unless you are recommending a builder within a sensible shipping cost from UK)

So, options seem to be either WLDR units, or KNS inlets.

WLDR units are easy to order BUT there is a post somewhere about the current version being the ones to have - how would I be sure this us what I was ordering?

I have tried to contact KNS and never received a reply. If anyone can advise, please do, but right now I can't make any progress with this
Shoot, a man could have a good weekend in Dallas with all that stuff...

Post Wed Nov 04, 2015 4:11 am

Posts: 379
45Brit wrote:
I'm just returning to an engine build I started a long time ago, which was shelved due to other projects.

Cams were an unresolved issue. I have never found any UK based engine builder who will attempt the fitting of the Enfield racing units, and I've been around vintage racing long enough to know most of the builders I'm prepared to pay money to. (Please don't reply with long posts about doing this, there's a thread with all that somewhere. I don't have the tools, don't know anyone who will do it, and that's that - unless you are recommending a builder within a sensible shipping cost from UK)

So, options seem to be either WLDR units, or KNS inlets.

WLDR units are easy to order BUT there is a post somewhere about the current version being the ones to have - how would I be sure this us what I was ordering?

I have tried to contact KNS and never received a reply. If anyone can advise, please do, but right now I can't make any progress with this


Brit, I think most dealers will stock the "current kit", as they were sold out long ago, even then you can just ask them if its current kit, and if you stil dont trust ask for a picture of the camlobes. If they are all 4 similarly shaped its an old kit, if 2 are more eggshaped and 2 are more oval then you have new situation. Even if you would stumble upon the old kit, the only difference with the new kit is in the exhaust cams. In the old kit they opened too long, overlapping with the intakes, it caused low RPM issues mostly. In the current situation the exhausts cams are much closer to stock WL ( a bit longer opening) but you wouldnt notice the difference at all if you would use the WLDR intakes and WL exhausts I think.

Post Wed Nov 04, 2015 6:33 am

Posts: 105
I have seen the cams in question on W&W website:

http://www.wwag.com/cgi-bin/WebObjects/WebSite

Can not speak if they are the new or old type, but W&W have been good with me in the past with responding to emails.

Not looking to hijack thread, OK maybe a little, I am looking to get a little more power out of my 45. Are these cams the ticket without going to a full stroker kit? Looking for budget friendly mild boost in power.

Post Wed Nov 04, 2015 8:35 am

Posts: 1730
.... that's an interesting all-round answer, because.....

1) W&W describe them as "exact copy of original WLDR cams" which from Samsup's earlier post in another thread, describes the original version, which may be incorrect. I'm going to believe Samsup on this, seeing as he supplies them and also, how to check when you have them.

2) more useful detail about the actual difference between the respective grinds. This actually appears to tell me that if the bike is a sod to start and won't idle, put the original exhausts back in and all will be well. This appears to be consistent with the KNS website; they have always offered exhaust cams as a stand-alone, drop-in item AND it tells me how to fix a possible problem ( which I may well have, the cams were bought in 2007 or. 2008) with parts I have to hand.

3) moving along, the answer seems to be that if you have a spare set of inlets, or the bike is in pieces anyway, KNS may be the most cost-effective solution PROVIDED your old exhaust cams are fit to re-use and you are in no hurry, but otherwise, buy a set of cams from whoever is the most cost-effective supplier.

I've just been having an interesting email conversation with a compatriot of Samsup's, who he probably knows. His recommendation, and it seems consistent with what others are saying, is that replacing the Venturi in the M88 carb with an M51 unit is cheap and useful (this may, or may not be true of an American bike, but virtually all 45s in Europe were military spec) so the most cost-effective upgrade with just a regular toolkit is exhaust cams, M51 Venturi or Mikuni conversion, #6 heads and modern ignition, preferably 12v electronic.

You always learn SOMETHING on here...
Shoot, a man could have a good weekend in Dallas with all that stuff...

Post Wed Nov 04, 2015 1:32 pm

Posts: 379
Architect wrote:
I have seen the cams in question on W&W website:

http://www.wwag.com/cgi-bin/WebObjects/WebSite

Can not speak if they are the new or old type, but W&W have been good with me in the past with responding to emails.

Not looking to hijack thread, OK maybe a little, I am looking to get a little more power out of my 45. Are these cams the ticket without going to a full stroker kit? Looking for budget friendly mild boost in power.


new type for sure :)

Post Wed Nov 04, 2015 1:38 pm

Posts: 379
45Brit wrote:
.... that's an interesting all-round answer, because.....

1) W&W describe them as "exact copy of original WLDR cams" which from Samsup's earlier post in another thread, describes the original version, which may be incorrect. I'm going to believe Samsup on this, seeing as he supplies them and also, how to check when you have them.

2) more useful detail about the actual difference between the respective grinds. This actually appears to tell me that if the bike is a sod to start and won't idle, put the original exhausts back in and all will be well. This appears to be consistent with the KNS website; they have always offered exhaust cams as a stand-alone, drop-in item AND it tells me how to fix a possible problem ( which I may well have, the cams were bought in 2007 or. 2008) with parts I have to hand.

3) moving along, the answer seems to be that if you have a spare set of inlets, or the bike is in pieces anyway, KNS may be the most cost-effective solution PROVIDED your old exhaust cams are fit to re-use and you are in no hurry, but otherwise, buy a set of cams from whoever is the most cost-effective supplier.

I've just been having an interesting email conversation with a compatriot of Samsup's, who he probably knows. His recommendation, and it seems consistent with what others are saying, is that replacing the Venturi in the M88 carb with an M51 unit is cheap and useful (this may, or may not be true of an American bike, but virtually all 45s in Europe were military spec) so the most cost-effective upgrade with just a regular toolkit is exhaust cams, M51 Venturi or Mikuni conversion, #6 heads and modern ignition, preferably 12v electronic.

You always learn SOMETHING on here...


Well the truth is that we have never ever in hour entire life found a NOS WLDR camgear kit that was identical to another WLDR kit.. All WLDR camgears that we ever encountered were modified in some way or another... sooo we made our based on a kit that we know were used by a harley racer. so to say they are 100% exact copies is not correct in a way, as for as far as I know there is no real reference cam like for the WL. They are 100% exact copies of a set that we have in our posession that is used by a harley racer, but given the issues it had with the overlapping of the valveopening times, we think that they were also modified to operate better at high RPM ( it sucked at low RPM ), hence we adapted them to be more suitable for " street use" . We have done that since I built a bike that I could not get started with the kickstarter due to this camconfiguration. I figured that most people if they are really into the racing they will grind their own lobes anyway, while now its more of a " simple swap " modification kit..

So bottom line, if you really want a true racer ( that will do topspeed, and with any lower RPM will start to run shitty) that the old type of cams is the way to go..

EDIT: Brit I see you mentioning swapping the exhaust cams. I think you mean intake cams. Its the intake you want to swap, basically to give the engine more time to breathe in.. It will get rid of its exhaust gasses without issue..

Oh and the idea of bigger venturi helps for sure. If you go for bigger intake valve, bigger intake moment, you NEED more intake capacity on the carburator too.. But if originality doesnt matter a modern mikuni carb is sayd to be even better..

Post Wed Nov 04, 2015 8:42 pm

Posts: 1730
Interesting stuff about cams. Old racing engines can have some pretty strange things in them, for sure. I had a BSA Blue Star built for grass track in the 1950s at one time, it had the biggest valves I've ever seen in classic 1930s "flat" port shapes plus Gold Star cams and a dope piston which gave it a nominal compression ratio of about 12:1. But, it was a very difficult bike to start, it had almost no actual detectable compression because the valves were never shut! Ran like crazy above about 1/3 throttle, though.... vintage racers are often like that....

Right now I have the stroker engine with repop WLDR cams, bought in about 2007/08 .... so if this bike is hard to start, refit the original WL exhaust cams, yes?


Correct about the KNS typo, I meant inlet cams as a stand alone drop-in.


I've never had a use for a "real" flathead racer, there is no class for them here in UK. But, now No 1 Son is getting involved in short track racing there is a Vintage class in that, with a true half mile event in S Wales so the temptation to build a bike for THAT, plus the VMCC grass hillclimb and a couple of other events (maybe a sprint...) is fairly clear. That's why I am resurrecting the 3rd engine, because I'm sure I will end up with a bike that is no real use on the street.

I've made a lot of progress with chassis stuff, so I can do this now. Sounds like I have enough cams and enough infirmation to assemble three sets for their various purposes.


I don't really care about having the fastest street 45 around, I did that with stupid unrideable BSA and Triumphs, long ago! I bought an Evo Sportster this year (most of the local VMCC bikes are 60s and 70s British twins, so you are wasting your time going there if you can't keep up) and I have the Honda, so any 45 will be just for "special occasions"
Shoot, a man could have a good weekend in Dallas with all that stuff...

Post Thu Nov 05, 2015 3:18 am

Posts: 379
Right now I have the stroker engine with repop WLDR cams, bought in about 2007/08 .... so if this bike is hard to start, refit the original WL exhaust cams, yes?

Probably yes, it could also be carburator related, but the cams definitely do not help the starting :lol:

Post Mon Nov 16, 2015 12:32 pm

Posts: 32
Location: El Paso, Texas
Back in '80 when my KHK cams were looking tired, I sent them to Weber Cams for a hard face and re-grind. At that time the grind was actually listed in their catalog, along with many other choices. I could not have been more satisfied with the quality of their work.
Fast forward 35 years and hundreds of new vehicle types...This company is still in business and, although our old farm equipment isn't listed in their website, they can still do work on antique cams and I would think they have pretty much any grind you could ask for. Cams are their business and always have been. Might be worth a phone call.

http://www.webcamshafts.com
'54 KHK since 8/70
'76 XLCH since 4/85
'97 Valkyrie since 10/96

Post Mon May 29, 2017 12:55 pm

Posts: 1730
Well, whatever cams this bike actually has (WLDR ones bought from 45 Depot in 2007/08 plus big exhaust valves) it starts just fine..

http://vid1023.photobucket.com/albums/a ... i9qd3y.mp4
Shoot, a man could have a good weekend in Dallas with all that stuff...

Post Tue May 30, 2017 10:17 am

Posts: 379
Sounds great! Maybe firing up doesnt matter with the type of cams at all, dont know really... I run a set of the revised WLDR cams on mine, and it definitely wont go as low in RPM as my stock WLA ( it will die and blow back hard trough the carb), but as soon as it picks up some rpm, its so much faster than stock WL

I dont think the old kit was bad, but the current kit should give a little more bottom power so to say, to make it more streetusable. It could be that your kit, if its the old revision ( likely so if bought in2008), that it will be even worse in low RPM.

Dont know if you have a second WL to test that theory with? We have revised the camsets back then based solely on theory, and what I observed when I was building my engine with a set of WLDR cams ( We found that intake and exhaust were open for a good deal of time, which we thought was a bad thing)

Post Tue May 30, 2017 3:56 pm

Posts: 1730
I'm accustomed to speedway and track racing Jawas with extremely long overlaps, and they start very easily.

One thing I would say, is that the carb is a 36mm Mikuni, not a 38mm one and that probably helps. The drag pipes don't do it any favours but this is a temporary set-up, I have a 2-1 exhaust designed using a speedway silencer, but that's for later.
Shoot, a man could have a good weekend in Dallas with all that stuff...

Post Tue May 30, 2017 4:24 pm

Posts: 379
Did you stroke the engine? I use 36mm and thats touching the limit on my otherwise stock engine. If I open throttle to wide on low revs it just dies, but when engine is revved up this issue is gone.. But this could be a fuelmixture issue just as well..

But maybe you are right about the cams. I would have to seriously test the old cam setup vs the new setup some day.. Never have the time for it tho
:mrgreen:

Post Wed May 31, 2017 12:10 am

Posts: 1730
It's a stroked engine, yes. It's so long ago that I honestly can't remember off the top of my head, but I'm pretty sure it's 4.5" stroke - I have the figure 836cc in mind - that's the reason for the T&O pistons.

I'd tend to agree that the 36mm Mikuni is as big as I'd want to go, the bike definitely falters at low revs. It would probably be better off with a smaller carb, 32mm or even 30mm but I don't have one to hand.

I also believe that a longer, 2-1 exhaust would be better for it, I do have one designed but need to get it made up.
Shoot, a man could have a good weekend in Dallas with all that stuff...

Post Wed May 31, 2017 10:30 am

Posts: 379
Yep. I actually realized after posting that I use a 34 MM carb, not 36. This seems to be the most used size mikuni on a 45. It works nice, but as said, the low revs are meh. But with stroke you get higher piston speed at same rev, so more vacuum, so 36 may be just fine

Post Wed May 31, 2017 12:02 pm

Posts: 1730
The most common size of Amal Concentric seemed to be 30mm or 32mm - 1 1/4" - but I suspect that was partly because Amals bigger than that were rare in those days.

If I had a 34mm I'd certainly try it.
Shoot, a man could have a good weekend in Dallas with all that stuff...

Post Wed May 31, 2017 4:09 pm

Posts: 33
Location: Victoria, Australia
45 Brit,
In Australian historical racing class C we are restricted to 32 mm amals which work well on 750 engines in various stats of tune.
I have a 34mm amal that I have tried at track days which seems to work fine as well

Post Thu Jun 01, 2017 1:49 am

Posts: 1730
If I was setting this bike up for the street, I think I'd go for a 30mm or 32mm carb.

To some extent, I'm following what previous builders have done with this engine. It has obviously been ported, but not relieved at some time, and came with a home-made manifold to mount the 36mm carb (judging by the ports, manifold and manifold bolts). I don't think it's wise to disturb the manifold, which seems airtight - and I can't be certain that the stock manifold would fit the ports as they are.

I suspect that the cylinders were ported, but not relieved, is that they were at +0.060" bore already. I followed this by sleeping them to standard bore, but that means I probably shouldn't relieve them. I do now have a set of new, repop barrels which came with another abandoned project, so ported, relieved barrels, probably with a larger manifold are probably somewhere in the future.

Right now, I want to try it, see how it goes. The lubrication system is a bit special, including piston oilers and a cutaway breather with the z-shaped valve shown in Victory Performance. I have a high-flow pump available, if I think it might be useful
Shoot, a man could have a good weekend in Dallas with all that stuff...

Post Sun Jun 04, 2017 12:23 am
GuS

Posts: 408
Location: Bergen, Norway
Sleeved and relieved. I see no broblems with that.
Image

Post Sun Jun 04, 2017 5:38 pm

Posts: 1730
Some see it as a problem. I have a set of repop barrels at original bore and given various issues with the existing set of barrels, I'd rather just dispose of the issue at source, and port and relieve the repop set
Shoot, a man could have a good weekend in Dallas with all that stuff...

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