Husaberg / Husqvarna and similar engines

On the internet I found several engines that look like husaberg / husqvarna 2000 engines, the manufacturers are JAWA, PRAGUE, VM, FOLAN, HIGHLAND ... Why so many similarities?

When you are making engine for same purpose you will endup with similar conception. But inspiration from each other is in place too

Folan and Highland (Hedlund) were more or less the same company.

Beta, Sherco and KTM as well as Husaberg and Vertamati/Vor are similar because they had the same designer for B, S, K all designed I believe by a Husaberg man. Vor was a copy by tywo brothers of a Husaberg having started as one.

Taffy

Thanks Taffy. So I imagine that the transition to layout whit closed cylinder between two crankcase halves and balancer shaft mounted coaxially to the crankshaft are improvements over a one piece cylinder engine with a classic balancer shaft.

yes, Husaberg were the only ones to try it. but don't forget that they STARTED with the balancer infront like most other when they made their 1996-2000 electric start bikes.

underneath those starter motors INFRONT of the engine is a balancer assembly.

secondly, the next geeneration of Husaberg engine that did arrive in 2001 was only there because Husaberg had their new design taken away by KTM and were told to "think of something else quickly but it can't look like the engine you just made for us to steal".

Taffy

I have a 2002 Praga ED610. Yes, comparing it to my Husabergs it is very similar. Water pump impellers are interchangeable among many other parts. Brakes, wheels,same ignitions etc.

Praga is very nice, you can not see many of those.
Praga and VM are same brand also. When the Praga ends one guy continued with manufacture under brand VM

So the husaberg 2001-2008 layout is not a real improvement over the classic layout, even if: having the cylinder tight between the crankcase halves does not lead to combustion or coolant sealing problems; The crankshaft does not flex due to the presence of the balancing countershaft and the greater distance between the main bearings but due to the weight of the main balance and the rigidity of the crank pin.

I believe from alot of research that my Praga is one of two 610s that were imported into the U.S. I have not been able to find the other one. It is a great bike, it does everything well as you would expect from a bike that is pretty much Czech version of a Husaberg. I haven't had to do any internal work on the engine but I would suspect some internals would be maybe not interchangeable with a Berg but very similar.

Danner said:

I believe from alot of research that my Praga is one of two 610s that were imported into the U.S. I have not been able to find the other one. It is a great bike, it does everything well as you would expect from a bike that is pretty much Czech version of a Husaberg. I haven't had to do any internal work on the engine but I would suspect some internals would be maybe not interchangeable with a Berg but very similar.

Click to expand...

Lets see some pictures of this thing!

Wauu! I even dont know that Praga were importing to US. Yes its is very similar to husaberg. Its pitty that they are not making them anymore same with berg
But you can buy JAWA 625 engine or 710 . They are still making them a think, but brand is JAWA-AMS
Show us some pictures!

Crazy idea: lc4 690 on exc street legal.. The era of husq630 husq570 husq510 husa650 husa570 smc660 is now over

Praga ED 610

Here you go.

if they had factored in the further distance apart of the main bearings before they started they would have gone to a 34mm+ big end. so when the balancer went onto the crankshaft I'm not sure but I think early on. They just underestimated the big end required. having said that, KTMs were all 32mm at the time.

I'd like a chat with someone who specialises in the old 400/450/520/525/530 and ask them what their pins look like and whether they had any flex.

Taffy

Dear Taffy I read about a bushmeccanic post about the main bearings of this forum. It reported on problems faced by those who raced big bore kits on ktm 520 525 560. Bushmeccanic focused on the fact that a 32mm crank pin combined with roller bearings with non-rounded rollers on the ends led to premature failures. The problem I think is the combination of three things that do not get along: heavy cranks (which spread at high rpm), crank pin not oversized (which makes the shaft a little flexible), bearing rollers that do not like lateral load at all of the crank that spreads due to the high rpm (because the rolls do not have the ends rolled up). I add that there are bearings that hold a pin in axis without flexing, they are for "tilting moment loads". But such bearings simply double deep groove ball bearings. However, I believe that rather than keeping the crank perfectly aligned without spreading, the crankcases would break. I add that the husqvarna 570/630, 510 450 have a 30 mm crank pin,

ther Husky's go at the big end but not on the mains. their mains are enormous - 72mm and there is no water pump - half speed - intermediate shaft just above it. Husabergs would love to have gone to a 72mm bearing but the w/p - hs - int shaft meant that it couldn't.

whereas the balls can take the speed loading of the 400/450/470 they can't take the power loading of the 628/644. a roller is required.

with a roller you need true precision of a built crank, you need solid and no flex and as you know - they flex. it isn't the pin flexing - even in the 32mm, it is the left and right flywheels leaving the pin.

with plenty of axial float they are all fine regardless of whether you like NTN - SKF or any other roller. they are 100% fine with 0.7mm plus.

as for that trachiodal bearing, I have the opposite view.

you ask; if I let it all flex in the bearing it is better.

I say; it just flexes even more and now we are in extreme trouble, basically the crank needs to either be held 'true' or to run wild.

my experience is that if you hold the crank and yes, let the cases take a great deal of strain that they are fine. nobody breaks cases - least not like that and how you mean.

as for the mains, nobody has trouble now, thanks to guys like myself coming on here day after day asking for far greater axial float.

But as for NTN being better Alfy, your a fool if you think so. you saw what I wrote in that other thread last week. it wasn't my customers having problems or I wouldn't sell them. you hold principles while selling in this job at your peril. You want the bearing to hit in the bottom of the 'L', right in the corner.

The SKF is a superior design and product altogether. they have dropped the NTN bearing from the Husaberg books but you can still buy the SKFs.

Taffy

I looked at the post on main bearings in the other thread. Beautiful photo of the hole in the crank pin where you can see the internal halo where the pin / hole contact is missing. Regarding the shape of the roller between bearings of different brands, I believe that to know which shape is best just look at the specifications and we will find that if the roller has a radius on the edge then it holds more axial load. However, regardless, it will not save the main bearings if the shaft clearance between the crankcases is less than 0.7mm, as you good said! I wouldn't be surprised if KTM removed a product from its books just for commercial deals

heidenberg said:

Lets see some pictures of this thing!

Click to expand...

I'll second that!

Goose916 said:

I'll second that!

Click to expand...

but they are 4 posts up?

Taffy

No ntn has ever failed in the same premature way as skf .... Includes zero endfloat on a 644 built in the UK.

Find a picture of a failed ntn out of a berg... There are none

Watch the fink desert race docos on YouTube. This is the test environment orangeberg was in to come up with the observation of ntn handling lower end float.

Wot runs with high gearing for hours, no green Laning

The code on the ntn specifically indicates special design to accommodate high axial loads and misalignment.

As for the ntn being dropped, even ktm au doesn't know anything about that. It's also still a current part number for 2021 model ktms.

The fact that skf need at least 0.7 mm to survive is proof they are less able to handle axial loading ... Nuf said, I've used both and prefer the cheaper one that lasts longer .