Ceramic coatings- to coat or not to coat

[toydoc]

Ya..G..made a lot of money just from being protested by rotax racers.

That big engine stuff…you guys just leave me in the weeds..amazing to do all that stuff… very impressed.

Woke up about 3AM thinking about your balance tube…TD. Couple things..the engineering behind the balance connection ..is for it to hold a pocket of ready to use mixed fuel…recovered from the stuff that doesn’t make it in. The other problem you have is… the rigid connection. You may be upsetting the carb resonance..(must be the same in the big block stuff you guys do)

I think that big hole in your tube,,is just too big. You need to add rubber in between to isolate the vibration.. from each other. Maybe make a chamber in the middle as well.

Gorkon..why don’t you find an old set of jugs…any brand..and cut the reed blocks off and weld them to your 338 jugs.

Racing today..I think the only cost effective..class is Formula 500. A class where cheaters cannot win in. Or champ..if you have the talent.

here is a good fast engine inside..no.. the gasket is not hanging in the case...notice the piston sides..

Exhaust side

You cant tell from the pictures, but the chamber port is U shape so it runs with the flow. The idea was to hold fresh charge, change the intake flow from the start / stop wave to a continuous flow intake. Also add intake volume. We did try a rubber intake and balance tube on other motor and made less hp on top. The motor maybe lossing a packing effect with adding a balance tube, not sure. What it looks like so far, balance tube likes to work under 9000rpm and like a tight intake / case with normal or smaller carbs. Now with that thought in mind, what if you made a valved balance tube. Use combination intake vacuum and exhaut pressure with adjustable spring tension to control valve timing. Like Ski-doo exhaust RAVE valve, on the intake side. May work..may not

 

[toydoc]

I'm so glad to see someone out there seriously running an SSR, how is that working out for you? We have no tracks in these parts and would have to travel half the continent to the nearest one, so I'm way out of touch with the scene. I had heard though that Rotax was the dominant force, is that true? Back in the day as I recall, the only reason Rotax was winning stuff really was because there was so many of them and very few Yamaha's.

Right now that SSR motor is in a 76 SRX. I have not run it in years. Seems like I was working with Polaris and Cat race teams for years but the last two I have been working more with rotax guys. Really havn't even look at my stuff, how sad is that

 

[Gorkon]

I can relate, my 79 SRX hasn't been touched in three years, too many other projects. The good news is that in that time I have logged no less than 12000 kliks seat time between my SRX mountain and 06 Attak! Yippee!

 

[toydoc]

Also machine the slides at the needle. Made interferece fit bushing for the needle. It holds the needle right in the center of the needle jet. Stock the needle moves side to side, rotates. Now it's right on center all the way up and down.

 

[RJH]

Try this instead of a valve.

Go find an ICC shifter kart air box. This box is designed for 125cc racing using a 30 mm carb.

So ..you will have to use that design..and build one for your monster.

You need to get the air resonance going in there…it turns into a mini supercharger…honest.

My kid could hear it hmmm at a high pitch when we got it tuned right…

Seems a little far fetched…but we won the championship.

Nice needle idea…..we changed the needle tapers on our needles..we used mj's to check the size. Again testing without mj in. never went above ¾ throttle…as that is when it bogs.

I forget to answer one of your posts…you had the carb with no mj..that is the TMS..Mikuni didn’t like that one….it just works on a fat needle idea.

You can see the air box here...it is tunable with 2 pipes...

 

[Gorkon]

I'm surprised that the needle is allowed to float around there to begin with!?

That airbox is a cool idea, I never realized such things existed before.

Bob, do you know a fellow named Roger Strut with Yamaha in Saskatchewan? He's supposed to be THE hot shot Yamaha mechanic from what I'm told. Might have a chance to speak with him soon. Thanks. G.

 

[RJH]

Air box....yes its hard work thou..you also need to put the overflow lines inside the box near the carb intake..so the float bowl senses the same air pressure as the carb mouth. There is wave design math out there to make it easy.for some.

No..not aware of that guy...I'm old..haven't seen my old across Canada buddies in decades...they are all sitting around druck somwhere probaly...

I do have lots of like minded fast buddie dudes here..in Muskoka where I just moved to...last Nov. We have 3 lake ice ovals...one is in my front yard.

I left anything to do with a spark plug in the early 80's even had an electric lawn mower. Got back into it in 99..

Just a note..there are machanics (good ones) and there are tuners..big difference. Unless the guy has won big races...be careful..you and certinally toydoc are most likely smarter.

 

[toydoc]

I would love to play with that Kart air box. They also don't cost that much, could be one of the best hp mods for the money.

Now days most of the time is spent on clutching and setup. Have a setup that keeps engine and clutch alignment right on. The motor plate is billet with machine gauge engine shoes. As belt size changes you can install the engine shoe for best performance without the engine coming out of alignment or offset. Each shoe is sized, machined, stamped.

 

[RJH]

Well..that is pretty slick stuff dude…I bet you have a ton of other stuff you would like to show…but on the other hand..its too good to share. That is one hell of a lot of work. Very cool. I hope you show us more stuff...you made...

I had to chuckle about your perception of us old guys and clutches…first let me say…we went to a few ovals this winter for the first time…on a track close to ½ mile..the 340 mods were in the low 70’s on a very cold day..…hmmm. My 340 stocker did close to 80 in the day…

I had supper with one of doo’s old race directors last week..we both agreed the new racing guys have nothing to compare to..its not that they can’t figure it out…but you only have to go fast enough to win… …when your pushed by 5 heats of guys from North America..in the day…things were much faster.

We made just over 100 HP in 76 and we ran about 100 mph with 440’s.

Engine mounts. We did not want it solid. Bolting down the crankcase solid only works if

1: you machine the pegs or bolt surface perfectly to the case jug face and crank.

2: You then need to laser level the chassis mounting surface to be perfectly square.

3:You then need to prevent any movement there. What happens is..the crankcase can twist taking away HP in un even loads.

We used a hard Durometer machined rubber mounts that fit into machined engine plate holes. We used Cat clutches..but it was too light for Yamaha’s harmonics. We had the resonance tested by a machine that calculated it by hitting the crank side with a 2 x 4..cool…we than added the calculated weight to the TZ rotor. We had no clutch or belt issues..clutch faces were just warm..Our clutches spent more time on the lathe than any engine mod

We never raced off spec belts...we had the luxury of selecting from a about 50 belts.,,or what ever it took to get what we wanted. We had belts to exact length and width..we wanted.

 

[Gorkon]

You guys blow my mind. toydoc, that is just too cool. I can't imagine the time and labour that went into that. Unbelievable! I was thinking of fabbing up a system like the 72 SR's for my sled so that I would at least HAVE adjustment!

I don't know if it will work yet, or even if it is the best choice, but have been thinking of using an Ovation primary since that is the most modern 340 primary available. People have suggested using a Comet or P-85, but I do not know if either of them will work with the Oil Injection and I do plan on keeping that operational. Have some neat ideas for the secondary as well, but one issue at a time for now.

To that end, it looks like my crank query is solved. It looks like either a 75 GPX crank or 340 Exciter crank will work just fine as well as the mag and stator from the Exciter. CV Tech will be doing the work I guess and seem knowledgeable and quite willing to work with me to solve any little problems.

Resonance testing!!!!? Wow! Every time I think that I'm going to far and getting too detailed, I just have to look at this thread! lol
I'm curious and interested in knowing what the clutches were doing on the lathe, exactly? Can you elaborate?

Thank you guys both so much for posting, you're both showing me stuff that I had no idea existed! What a bleeping education this little project is turning out to be. God I love hot rodding! Best. G.

 

[toydoc]

Thanks guys, but lots of people put lots of time in the stuff I have. I have been very lucky to know alot of good people. As far as what info i'll share, I try to tell anyone anything they want to know (if I know it). I like to see everone go fast, not burn down, have fun. The only thing I can't (or won't) talk about is someones setup, test / prototype parts or ideas in the works. I don't own any sled, at any race track. If you find the sled owner and they want to talk, I'm good with that. But it's their money and up to them, not me.

Bob, I didn't have a perception that your a old guy. My perception is we are both OLD GUYS
I'm way to old and fat to race anything now days. I should have said I spend more time on clutching and setup now days then building motors. Back in the day we would make our own fly weight and jig to make lead rivets to add. Then turn both clutches on a lathe, true the face and setup the face degree for best up shift. Check drive belt face degree (they are not all the same). Then set the track drivers & shaft in the lathe and true them up also. Then have endless time into setup time on the track.

Things have change allot for me since back then. Heres a track HP graph to think about. It's a Polaris 800, the base line RED run is a drag race setup used on the track for a season. The BLUE run was made after 5 hours of clutching and setup work. Thats a 20HP gain to the track. What really stands out is the RPM of both runs. They are within 80rpm of each other.
9300 rpm, red run
9380 rpm, blue run
So this graph can show what happens when you clutch to set rpm and not maximum efficiency at best rpm. This is a extreme case but good to learn from. Most times I see 5~10 hp gain at the track and thats a good days work.
Keep in mind, a 10hp gain at the track is the same as 20hp in engine mods.
Also worth noting is that Polaris motor was made to run at 9600rpm. Came off the engine dyno with peak hp at 9600rpm, but wouldn't pull that rpm on the track or track dyno. It made best hp at 9300rpm.

 

[Gorkon]

Amen to set-up. One particular episode of Track Time comes to mind where this young man came to the line with a plain jane white 82 Capri with a 302. It didn't look like much, not even under the hood, a few go fast goodies and a set of sheet metal valve covers, maybe 9 inch slicks. I don't even recall a roll cage.

Everyone guessed wrong! I never saw anything like it when the car literally exploded off the line, more like it LEAPED to mid track, set the front wheels down and ran a 9.34!!!!!!!!!!!!!! With a 302! When it left, it never spun a tire, never kicked sideways, nothing! It looked like it was an almost effortless, quiet leap to mid track, well maybe not mid track, but I was in shock! The only thing that could have been was set up well!

I had a friend with a Viper set up like that too, he would eat my 06 Attak every time. I would watch in amazement when he would just leap off the line and be setting the ski's down 5 to 6 lengths ahead whilst I was still spinning trying to get off the line! I could reel him in on longer runs, but in 660, forget it!

I would love this little SS to be like that. Hope I can learn from you guys to make it so!

As for the old and fat, yah, too many beers and too many hot dogs, my 10 year old will be piloting for good reason! Thanks. G.

 

[Gorkon]

Try this instead of a valve.

Go find an ICC shifter kart air box. This box is designed for 125cc racing using a 30 mm carb.

So ..you will have to use that design..and build one for your monster.

You need to get the air resonance going in there…it turns into a mini supercharger…honest.

My kid could hear it hmmm at a high pitch when we got it tuned right…

Seems a little far fetched…but we won the championship.


Hey Bob, just found this post on a Sno Jet proto type on vintage sleds and thought of your post here and the cart airbox. I am unfamiliar with the Jets so don't know if they ran this type of airbox on the production units or not, but it sure seems like it could be someone was thinking of using the intake resonance pulse with this airbox design. I have also been told that the SX 440 Jet would take a GPX's lunch money any day. I cannot comment there as I never saw them on the tracks competing in the day, seemed GPX's owned the track until the liquids came along. Your thoughts? Thanks Bob. G.