503 Engine Mods
- Thread starter ozzydog
- Start date
Going to try
There is a popular mod shop up the road from me, Speedwerks they are out of forest lake Mn. I'm going to bring in my can and see if they can make me one. For a little more HP, and to lighten it up some. Also going to put in V force reed's I already have them, Will install this summer. That will be plenty for me.
There is a popular mod shop up the road from me, Speedwerks they are out of forest lake Mn. I'm going to bring in my can and see if they can make me one. For a little more HP, and to lighten it up some. Also going to put in V force reed's I already have them, Will install this summer. That will be plenty for me.
B
BlazinBya
Member
I often wonder the same thing,so I asked LRD,he was the guy modding the skidoo rev fanner to be the ultimate light weight boondocker.He is extremely knowledgeable when it comes to getting the most outta the fan motors.Here is what I recall......The biggest problem with upping the power on a fanner is cooling,also the 503 block doesn't have alot of room between the cylinders for boring out and upping the CC's.I think he told me he could take mine up to about a 530cc or so along with some mild porting and head work.I believe he said it would run around 700 bucks and would yield roughly 75 reliable horsepower,anymore than that outta the 503 and your asking for troubles with durability.He did say that he had bumped his 550 fanner,which is a better motor to mod,up to 90 horse or so.I think the 550 motor would be the ticket in a hawk myself.Nearly as much oomph as the 600 liquid without the added weight penalty! Now were talkin.......I noticed while riding with the 600's and 800's the other day that my lightweight fanner would pop up on the snow and plane out sooner than the heavier more powerful hawks would.I dont know if it was due to the lighter weight or the lack of track speed that was letting it plane sooner,but I was heavier than two of the guys and wearing a 20 lb backpack so....?I was really thinking I was going to upgrade this year to a liquid 600 136 but instead I think I'll rip rip the fanner for awhile longer....after some slight motor mods,a longer track,and the new simmons gen2 ski I think I'll be content.
S
snowhawkaddict
Banned
I am vindacated!
The 503 rules!
It can't trench in when it does not have the power to, so its only option is to get moving.
The extra performance, wear, poor mileage, and failures of the larger liquids are not worth the wheelies on demand, and if you want them put about $1,500.00 into clutches!
LRD is the man http://www.snowest.com/forum/member.php?u=45644
And yes the 550/620 would be the answer as he has described to me before, yet his application was for a Summit not a Snow Hawk designed around the 440/503F.
He has specs for the European 550HO's.
For now stick with what works, the 503F, notice it's still available. http://www.rotax.com/en/Engine/2004/Aircraft/Engine.Models.htm
We need thousands of them at $7,999.99,and a handful of 6 and 8's for those who want to deal with them!
Completely redesign a second generation of the machine, and give me a EFI 175-300-500-700cc two and four stroke liquid singles with radiators?
This is not the only option! http://www.brp.com/en/Products/
Artic Cat aka Suzuki/Showa, Yamaha, Kawasaki, KTM, hell even Polaris, and Honda.
Then you will see tens of thousands sell for $3,999.99-$9,999.99!
The 503 rules!
It can't trench in when it does not have the power to, so its only option is to get moving.
The extra performance, wear, poor mileage, and failures of the larger liquids are not worth the wheelies on demand, and if you want them put about $1,500.00 into clutches!
LRD is the man http://www.snowest.com/forum/member.php?u=45644
And yes the 550/620 would be the answer as he has described to me before, yet his application was for a Summit not a Snow Hawk designed around the 440/503F.
He has specs for the European 550HO's.
For now stick with what works, the 503F, notice it's still available. http://www.rotax.com/en/Engine/2004/Aircraft/Engine.Models.htm
We need thousands of them at $7,999.99,and a handful of 6 and 8's for those who want to deal with them!
Completely redesign a second generation of the machine, and give me a EFI 175-300-500-700cc two and four stroke liquid singles with radiators?
This is not the only option! http://www.brp.com/en/Products/
Artic Cat aka Suzuki/Showa, Yamaha, Kawasaki, KTM, hell even Polaris, and Honda.
Then you will see tens of thousands sell for $3,999.99-$9,999.99!
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would a newer brp 550 drop right in a hawk fanner
S
snowhawkaddict
Banned
Yes.
Simple mods required, careful what you wish for, aircraft still utilize 503F for a reason.
Simple mods required, careful what you wish for, aircraft still utilize 503F for a reason.
i thought you liked the 550 tony
after reading the HP you could get out of the 550 the wheels are a turning!!!
and a zx2 with a ultra light camoplast!!! i wonder how light a 503 fanner could get?
why would i want a 600 LOL
after reading the HP you could get out of the 550 the wheels are a turning!!!
and a zx2 with a ultra light camoplast!!! i wonder how light a 503 fanner could get?
why would i want a 600 LOL
S
snowhawkaddict
Banned
I like what works.
It's not the engine that makes the machine, but it sure helps to have the power you "need" when you "need' it.
I "want" quality and reliability not Viagra and a transvestite!
It's not the engine that makes the machine, but it sure helps to have the power you "need" when you "need' it.
I "want" quality and reliability not Viagra and a transvestite!
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those transvestites are sneeky Tony! im not even gonna ask!!!
600 Sdi
After the best snow trip of my life I don't know what hawk to ride anymore. I love the power of the 8 but the six sure flips around alot easier and still climbs like a mofo. Could be the different track setups but don't think that is the big dif. I think a 600 sdi or maybe a e-tec is in order for me with a 144. What u all think?
After the best snow trip of my life I don't know what hawk to ride anymore. I love the power of the 8 but the six sure flips around alot easier and still climbs like a mofo. Could be the different track setups but don't think that is the big dif. I think a 600 sdi or maybe a e-tec is in order for me with a 144. What u all think?
i just bought a 550fanner out of a 2006 sled
have arranged with a guy here in Ontairo to do the swap and build up of it this summer once i get my hawk!!! cant wait till next year!!! he said he has built a lot of these engines!
im gonna try to lighten it up some more first with a zx2 and light weight camoplast!!
you guys have any other things i could do to lighten up this beast!!
as per the 550 big bore, new head, ceramic coated pistons, stroked, v force reeds, larger Carbs, Ram cold air! and increase cooling to the engine. he said reliable 85 hp!! last but not least, some clutching so it pulls like a champ!!
he said his moded 550 fanner with clutching is smoking fast!
how about a lightened fanner that could do wheelies!
do you guys think im wasting my $$$ building this machine?
all in all i think i will be about 7K into it total when im all done!
i could get a newer 600 cheaper, but it just wouldent be the same!
have arranged with a guy here in Ontairo to do the swap and build up of it this summer once i get my hawk!!! cant wait till next year!!! he said he has built a lot of these engines!
im gonna try to lighten it up some more first with a zx2 and light weight camoplast!!
you guys have any other things i could do to lighten up this beast!!
as per the 550 big bore, new head, ceramic coated pistons, stroked, v force reeds, larger Carbs, Ram cold air! and increase cooling to the engine. he said reliable 85 hp!! last but not least, some clutching so it pulls like a champ!!
he said his moded 550 fanner with clutching is smoking fast!
how about a lightened fanner that could do wheelies!
do you guys think im wasting my $$$ building this machine?
all in all i think i will be about 7K into it total when im all done!
i could get a newer 600 cheaper, but it just wouldent be the same!
550HO Spec's?
So what is the Spec's of the 550HO?
The Standard 550F(70hp at 7000rpms) use's a 9.6cr, and the early ones used 34mm Carbs, later ones use 30mm carbs, and are rated 58hp at 6800rpms.
The Standard 380(36hp) with a 9.6cr, and the 380HO(48hp) with 11.2cr, both rated at 7000rpms with 30mm Carbs. 380HO with a better-Tuned pipe Dynoed 57.26hp at 7000rpms.
LRD's 550F Big Bore was (81mm x 61mm) 628.9cc, not 620cc, unless he made more than one.
If Designed and built right, using a (11.2cr to 11.8cr) and a good Tuned Pipe these motors should make:
503(496cc) at 90% efficient at 7000rpms = 74hp
550(553cc) at 90% efficient at 7000rpms = 82hp
550BB(628cc) at 90% efficient at 7000rpms = 93hp
=======================================
So what is the Spec's of the 550HO?
The Standard 550F(70hp at 7000rpms) use's a 9.6cr, and the early ones used 34mm Carbs, later ones use 30mm carbs, and are rated 58hp at 6800rpms.
The Standard 380(36hp) with a 9.6cr, and the 380HO(48hp) with 11.2cr, both rated at 7000rpms with 30mm Carbs. 380HO with a better-Tuned pipe Dynoed 57.26hp at 7000rpms.
LRD's 550F Big Bore was (81mm x 61mm) 628.9cc, not 620cc, unless he made more than one.
If Designed and built right, using a (11.2cr to 11.8cr) and a good Tuned Pipe these motors should make:
503(496cc) at 90% efficient at 7000rpms = 74hp
550(553cc) at 90% efficient at 7000rpms = 82hp
550BB(628cc) at 90% efficient at 7000rpms = 93hp
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Fanners have a limit
I've been down the road your on serveral times on a few Fan cooled sleds, and in my opinion modding a fanner just causes it to heat up faster and loose power sooner. If your not familiar with the term "heat soak" it happens when an engine becomes so hot it begins to actually lose power and efficiency. This happens all the time on any fan cooled sled, especially if you mood it. So if you mill the heads, or port it or any do other engine mod yes it will work just like it does on a liquid cooled engine, but there is no way to cool off all that extra power, so it actually overheats(heat soak) sooner.
Find a used 600 liquid it will be totally worth the $$, keep your fanner and just enjoy it for what it is. Maybe lighten the track, or other lightweight modds, but I wouldn't touch the motor.
I've been down the road your on serveral times on a few Fan cooled sleds, and in my opinion modding a fanner just causes it to heat up faster and loose power sooner. If your not familiar with the term "heat soak" it happens when an engine becomes so hot it begins to actually lose power and efficiency. This happens all the time on any fan cooled sled, especially if you mood it. So if you mill the heads, or port it or any do other engine mod yes it will work just like it does on a liquid cooled engine, but there is no way to cool off all that extra power, so it actually overheats(heat soak) sooner.
Find a used 600 liquid it will be totally worth the $$, keep your fanner and just enjoy it for what it is. Maybe lighten the track, or other lightweight modds, but I wouldn't touch the motor.
One thing that can help on the Hawks is if you remove the center disk between the forks . Granted you can't always run without it but you'll be amazed at how much the wider ski keeps the snow from going in . It actually makes a huge difference in normal riding conditions because the air flows under the exhaust and around the case which is not the norm for the way the engine is put in the typical sled .
