• Husqvarna Motorcycles Made In Sweden - About 1988 and older

  • Hi everyone,

    As you all know, Coffee (Dean) passed away a couple of years ago. I am Dean's ex-wife's husband and happen to have spent my career in tech. Over the years, I occasionally helped Dean with various tech issues.

    When he passed, I worked with his kids to gather the necessary credentials to keep this site running. Since then (and for however long they worked with Coffee), Woodschick and Dirtdame have been maintaining the site and covering the costs. Without their hard work and financial support, CafeHusky would have been lost.

    Over the past couple of weeks, I’ve been working to migrate the site to a free cloud compute instance so that Woodschick and Dirtdame no longer have to fund it. At the same time, I’ve updated the site to a current version of XenForo (the discussion software it runs on). The previous version was outdated and no longer supported.

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    Coffee didn’t document the work he did on the site, so I’ve been digging through the old setup to understand how everything was running. There may still be things I’ve missed. One known issue is that email functionality is not yet working on the new site, but I hope to resolve this over time.

    Thanks for your patience and support!

LC430 porting

currently restoring/rebuilding an air cooled 430 with a rooney ported cylinder from 1985 let me know what specs you need this is engraved 'p rooney 12/85 A' I don't know what the 'A' means presumably similar to stage one, i do not have another cylinder to compare and never ran the bike before tear down.
 
jo360 said:
currently restoring/rebuilding an air cooled 430 with a rooney ported cylinder from 1985 let me know what specs you need this is engraved 'p rooney 12/85 A' I don't know what the 'A' means presumably similar to stage one, i do not have another cylinder to compare and never ran the bike before tear down.
Click to expand...


can you measure the exhaust port width and let us know? does it look like it have had many hours on it after porting?
also, can you measure from top of cylinder barrel to top of exhaust port?

thanks :)
 
exhaust port dimensions:height 33mm, width 53mm ,40mm from top of sleeve down to top of port.
cylinder will be going in for its last oversize (87.5mm) soon as piston arrives, porting was carried out december 1985 probably same sleeve.
 
Palito said:
I have never seen a exhaust port in two parts, you mean it has a bridge running down the center of the port. Interesting, that would support the ring so you could have a wider opening. I would really like to see such an exhaust port, I would think that the exhaust gasses being so hot would warp the bridged portion between the two ports.
What models came that way?
Click to expand...
The 360 of this section has a divided exhaust port. The current 125 husky does as well it has power valves that are different than most they slide in and out of a hole like thing. The current yamaha 125 has similar power valve design but I only guess, don't know for sure if the port is divided.
 
jo360 said:
currently restoring/rebuilding an air cooled 430 with a rooney ported cylinder from 1985 let me know what specs you need this is engraved 'p rooney 12/85 A' I don't know what the 'A' means presumably similar to stage one, i do not have another cylinder to compare and never ran the bike before tear down.
Click to expand...

The air cooled 430 probably should get it's own thread. The air cooled 500 has a divided transfer like in these pictures and the same reed set up. The air cooled 430 just has a passage for the transfer, no divider and the reed block is different and can be ported so to speak quite a bit. At least unless someone corrects me.
 
jo360 said:
exhaust port dimensions:height 33mm, width 53mm ,40mm from top of sleeve down to top of port.
cylinder will be going in for its last oversize (87.5mm) soon as piston arrives, porting was carried out december 1985 probably same sleeve.
Click to expand...
And what exactly has paul rooney done to your cylinder? doesen't sound like he has done anything with the exhaust port timing..
 
Palito said:
I have never seen a exhaust port in two parts, you mean it has a bridge running down the center of the port. Interesting, that would support the ring so you could have a wider opening. I would really like to see such an exhaust port, I would think that the exhaust gasses being so hot would warp the bridged portion between the two ports.
What models came that way?
Click to expand...

Yes, that's that, a bridge !
I have that on a 430 ae motor coming from OZ.
I've heard that early models had no bridge, but late models had it.


DSCN1628.JPGDSCN1627.JPGDSCN1626.JPG
 
The 430 auto crankshaft is very far from a full circle filled design. The standard shift 430 is pretty close to a full circle filled design it just has four lightening holes. I am not much of an expert on modern or period porting techniques but this shouldn't be lost in analyzing the situation.

I have a bike (88 wr 430 engine) I worked over the air box and the exhaust system and used essentially the least tampered with read virtually stock cylinder. I also have a cordless timing system and access to private land if someone wants to get an idea of how much gains (compared to that) if any they have accomplished than I got. 06076

Fran
 
Michel Dufayard said:
Yes, that's that, a bridge !
I have that on a 430 ae motor coming from OZ.
I've heard that early models had no bridge, but late models had it.
Click to expand...

Very interesting, and on an Auto. What year..'87 or '88 maybe. And a 2 ring piston, is that original?
Thank you for going to the trouble of posting the photos here, very much appreciated.
Now I'm wondering if it was to support the ring to allow for a wider port, but then again the bridge effectively makes it smaller.... Problem with engineering designs is that there is always compromise.
 
I have a '87 wr 400 and that one does not have any bridge.
also, my 430 cylinder had a 2 ring piston. I want a new piston for it, but can't find anyone having it. think it is a wiseco..
 
the cylinder has been smoothed out dags and edges smoothed, port passages cleaned up etc, as i said 'A' probably means a tidy up like a stage one, i will re-measure to confirm and post a couple of pics.
 
ok managaged to have a good look today in the daylight and sure enough top of exhaust port to top of cylinder 39mm the width is 56mm but i noticed that the sleeve sticks into the port about 3mm (sleeve must have been replaced and not matched correctly or maybe even left smaller as a safe guard against snagging a ring), the rest of the ports have been cleaned up and match the sleeve pretty good.remember that this sleeve is now at 87.5mm on its last overbore so this may also impact on the measurements.
 
Palito said:
Now I'm wondering if it was to support the ring to allow for a wider port, but then again the bridge effectively makes it smaller.... Problem with engineering designs is that there is always compromise.
Click to expand...

Yes, a bridge in the exhaust port is to allow a bigger total port area and eliminate the problem of the rings catching on a large unbridged port. Lots of bikes use them, my '79 Maico 440 and my Honda CR500 both have bridged exhaust ports, I think my '77 Penton/KTM 400 has one too.
 
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