Author Topic: How to Run Saito 62 and 72 in reverse (clockwise) (Read 31614 times)

Martin Quartim · « **on:** July 13, 2011, 09:14:24 PM »

I have mentioned before about reversing the Saito 62 and 72 by changing the cam gear, and I just got the confirmation from Horizon that using the front cam gear from the Satio 200Tii part number SAI182TD34 we can indeed reverse the Saito 62 and Saito 72. Below is a diagram to achieve the setup.

This is the part from Horizon Hobby http://www.horizonhobby.com/Products/Default.aspx?ProdID=SAI182TD34

There are plenty of good pusher props for these two engines. My favorite 4S props are from JXF(or Xoar) and they have 13x6 and 14x6 pusher props.
http://www.himodel.com/plane/JXF_14x6_inch_Beechwood_Propeller_Counter_Rotating.html
http://www.himodel.com/plane/JXF_13x6_inch_Beechwood_Propeller_Counter_Rotating.html

APC has 13x6 and 14x6 pusher props. Zinger has many pusher props to choose from http://www.zingerpropeller.com/Pusher.htm

Martin

Martin Quartim · « **Reply #1 on:** July 13, 2011, 09:39:02 PM »

I just found this other left cam gear that should work for the Saito 56

http://www.horizonhobby.com/Products/Default.aspx?ProdID=SAI130T34

Martin

Mike Callas · « **Reply #2 on:** July 13, 2011, 10:30:52 PM »

Will that work on a Saito 40?

Martin Quartim · « **Reply #3 on:** July 14, 2011, 06:39:31 AM »

I could not find a left cam gear for the Saito 40, but perhaps there is one.

Martin

Allan Perret · « **Reply #4 on:** July 14, 2011, 11:10:57 AM »

Hey Martin:

Great info, thanks for sharing this.
I might give this a try if I ever decide to do something with my Saito 62.
My engine is NIB, still needs to be broken in.
Would you do the mod first from the git go; or break it in with normal rotation and then do the mod.

Have you actually done this to one of yours ?

Martin Quartim · « **Reply #5 on:** July 14, 2011, 06:44:29 PM »

Hi Allan,

Yes I would mod it before breaking in and if I replace this new part into a used engine I would treat the engine as it was new.

I have not tried this yet. I just found out this can be done for sure a few days ago and thought I would share with you all.

The electric guys swear there is a significant advantage running the prop clockwise, so why not give it a try the part is pretty cheap.

The French polish the contacting area of the cam. But I not sure if this is such a great idea, at least we do the very opposite in cylinder liner to keep a good film of oil.

What do you guys think about that?

Martin

Air Ministry . · « **Reply #6 on:** July 15, 2011, 02:44:11 AM »

Quote from: Mike Callas on July 13, 2011, 10:30:52 PM

Will that work on a Saito 40?

Breringer ran counter rotateing .40s on his red twin Caudron.
Some picturs here , via something on the prop .
Dont know if thats where it showed the cam ' apart ' with a lobe before fitting .
romour was he had ordered unassembled cam from Satio. This refers .40 only .
-----------

Are some fancy automotive cam ' pre lube ' and run in products available.
Some recomend V light valve springs whilst the revs are kept low to mate surfaces .
Then the full strength ( double) springs are installed.General theory is low revs ( below about 1/2 )
on stroppy cams , so as to prevent galling from high pressures from high lift rates forceing mateing
surfaces dry .

Std. on a Commando to reface LIFTERS on dissasembly, ropey hardening on early cams makes them
a bit delicate, think the idea was to keep it below 4.000 for the first 200 miles specifically regarding
cam / lifter bedding in / mateing, as a degree of self hardening occurs if its got right .

The pinto engines tear up / blue / soften & hollow cams / lifters if the little oil spray feed pipe, aimed
between cam / followers is not de sludged or replaced. POINT BEING the breather feed through cam gear on satio
IS the lubrication . If its functioning incorrectly , oh dear . Excess breathing new shouldnt be a concern,
itll keep it lubed on run in . V hard ( chrome ) rings take quite some time before they seal & stop excess blow by .

more enlightened types might find this relevant .

Bob Reeves · « **Reply #7 on:** July 15, 2011, 06:43:19 AM »

Martin, Have you found the JFX props to be true to the stated pitch? Noticed they do not have a 13-7 counter rotating which is what I would really like to try. They do have the 13-6 and a 13-8. If they are like the Rev-Up's the 13-8 might be closer to 7 than 8.

I have never had to disassemble any of my Saitos, wondering if you have to pull the piston to change the cam. If you don't need to pull the piston I would think minimal break in would be needed, if you have to pull the piston might not be a bad idea to install a new ring and break it in all over again.

Martin Quartim · « **Reply #8 on:** July 15, 2011, 08:37:06 AM »

The true pitch of the JXF I got are very close to the stated pitch in the middle and it decreases a bit towards the tip, which I think is a good thing. For example it goes from 6 in the middle to 5.6 5.8 at the tip. The pitch variation from prop to prop and from blade to blade is by far better then other wood prop brands I have tried. I have been using JXF electric ones for a few years now, they are stronger then regular T.Flite P.P and work amazingly well.

I believe you can special order a JXF 13x7 pusher props from HImodel. As matter of fact they might even supply a 3 blade pusher prop. You can inquire this from the help desk. Xoar may do the same in the US.

I have not disassemble a Saito, but it seems we need only to open the cam gear cover and disassemble the pushrods to do the job.

Martin

Bob Reeves · « **Reply #9 on:** July 16, 2011, 08:10:38 AM »

I just have to try this.. I sent HiModels a message asking about the availability of a 13-7, will see what they say. Will probably order a couple each of the 13-6 and 13-8's even if they can get 13-7's.

Bob Reeves · « **Reply #10 on:** July 16, 2011, 08:13:18 AM »

Doesn't the 56 and 62 use the same cam gear.. Just wondering if this will also work in a 56?

Think I answered my own question.. Searching the Horizon site it looks like the 56 uses a different gear, at least the codes for the parts between the two cam gears are different. Oh well, I have another 62 I can start with.

More research.. This should work in the 56, at least the other cam gear that this twin uses is the same number as the one in the 56..

http://www.horizonhobby.com/Products/Default.aspx?ProdID=SAI130T34

I think we are out of luck on the 40 but they do make a 60 twin that might work for the 30. Off to do more research...

Jim Kraft · « **Reply #11 on:** July 16, 2011, 06:07:42 PM »

I have taken quite a few Saito's apart. You do have to pull the cyl. off at least partially in order to get the push rod covers off in order to remove the push rods and and cam case. You do not have to pull the cyl. clear off, but that is probably the easiest way. I have pulled them just far enough to get the pushrod covers and pushrods out. I have never had a problem with the rings seating again when taking them apart and putting them back together with the original ring.

Bob Reeves · « **Reply #12 on:** July 18, 2011, 04:53:49 AM »

Thanks Jim, I have one of each cam gears coming (56 and 62), going to be fun to play with. I have a kit bashed SIG SomethingExtra I converted to CL that will be a good test bed.

HiModels answered my message and said that they will include 13-7 JFX props's on the next order and put them on the web site. When they get this done I'll be placing a prop order.

Not sure how long it will take to get everything in and something in the air, will report back my progress.

Jim Kraft · « **Reply #13 on:** July 18, 2011, 11:28:22 AM »

I think this is a very interesting project. I will be waiting for the flight reports. Might just bring Saito's back to the fore front for stunt. I know the guys flying electric like to run reverse props, and say it makes a big difference. It makes it all the more viable since there are cams available that will work. I have done some work on Saito's for the guys at the R/C club, and have found them fairly easy to work on. About the only trick is getting the timing right when putting in the cam gear. It is pretty easy to get them off one tooth.

Bob Reeves · « **Reply #14 on:** July 18, 2011, 03:52:49 PM »

I didn't order any other pats but the cam gears, do you think I might need any gaskets or screws?

A while back Bob Z posted how to make a tool for setting the cam timing but not sure it will work with the reverse cams. I made one but have never used it, like I said I've never had a Saito apart.

Jim Kraft · « **Reply #15 on:** July 18, 2011, 07:13:17 PM »

I have always been able to reuse the gaskets and screws. I made a cam alignment tool also. If I remember right they show the tool in the instructions for my Saito 90 Twin. You may have to come up with a different way for the reverse cam, although it may work out in one or the other of the lifter holes. If neither of the lifter holes line up with the hole in the cam, you might try a dowel pressed in against the cam shaft through a lifter hole while putting it on the engine. You might need three hands. LOL

Bob Reeves · « **Reply #16 on:** July 24, 2011, 02:15:39 AM »

Yesterday received the two cam gears I ordered, they look identical but haven't taken them out of the packages yet. Also ordered a few props from HiModels, man they sure ding you for shipping plus 3% if you use a CC or PayPal. I had them ship by slow boat, wasn't going to pay $28 shipping on $26 in props and it was still 12 bucks. Oh well it's only money.....

Chris Wilson · « **Reply #17 on:** July 27, 2011, 05:42:53 PM »

Is there any De Sax offset that could interfere with reverse running?

Just thinking out aloud.

Jim Kraft · « **Reply #18 on:** July 28, 2011, 09:28:25 AM »

I don't believe there is any offset in any of the Saito's I have seen.

Bob Reeves · « **Reply #19 on:** August 20, 2011, 11:47:56 AM »

Installed the cam in a 62 this morning and ran it.. Quickly discovered none of the timing marks are correct and if you follow the diagrams above I doubt it will run. What I ended up doing was removing the back plate and valve covers from a 56 and used it to help me set the cam on the 62. I rotated the crank and noted what position the crank was in just as the intake valve started to open. I then set the 62 to the same location except of course for clockwise rotation. When I had it together using the timing marks the intake valve would open after TDC, the 56 opens just before TDC which made sense to me so I set up the 62 to do the same.

I first put the 13-6 reverse pitch prop on the 56 turned around backwards so the leading edge would be the same and got a tach reading of 8900 WFO. I then put the 62 on the stand with the same prop, ran it at low RPM for 15 minutes or so then bumped it up. It turned the same prop at 9200 which I would guess is in the ball park for having everything right. 3 grand over a stock 56, same prop and fuel..

Am I the first one to install a reverse cam? The timing being off if installed from the above diagram is pretty obvious with the new cam. I'm wondering if the diagram is what needs to be done with a stock ccw cam to reverse the engine. Could be we don't really need to buy the cam, just move the timing?

Now the bad news, I went inside the shop and left the engine to run out the tank and forgot to richen it up. After it quit I went out and it now has no compression, none zip squat. The fuel I was running had quite a bit of castor in it and I'm thinking the ring and or valves may be gunked up with burnt castor from running too hot, (I hope). Tomorrow I'm planning on trying to get it started using my normal 20-20 all synthetic and see if it wont clean out the castor and free up the ring. If that doesn't work guess I'll be ordering a new ring.

Couldn't wait, so braved the 100+ heat and put the 62 back on the test stand. All better now, ran 5 ounces of YS 20-20 through it and it's back to normal. I know castor has no place in 4 strokes but guess it has to be pounded in my thick head more than once

Jim Kraft · « **Reply #20 on:** August 20, 2011, 07:45:35 PM »

Thanks for posting your experience Bob. I don't think there is any way to make the stock cam work in reverse as it would always open the intake valve first instead of the exhaust when running in reverse rotation.

One way to check valve timing is to get the engine at TDC opposite the firing stroke where both valves are open a tiny bit as there is some overlap. You can rock the crank back and forth and they should be open the same amount at TDC. You do have to have the valve covers off to see this, and probably the back cover to see if you are at TDC. I bet you are right on.

Martin Quartim · « **Reply #21 on:** August 20, 2011, 08:05:47 PM »

Hi Bob,

I have not got my parts yet, it takes for ever to clear customs down here. Any how, I had plan to work on this project after Brazilian Nationals in November.

The Diagram came from Horizon Hobby Tech Support. Could you make a diagram of how you made yours to work?

Looking forward to a flight report.

Martin

Jim Kraft · « **Reply #22 on:** August 20, 2011, 08:49:04 PM »

I am not sure it would work, but after looking at my Saito twin, I think you could use your stock cam with the left cam housing from the 182 twin as the pushrods are reversed which would reverse the rotation. I do not know if the cam housing would fit on yours for sure though.

Well, after going to the Saito 182 twin parts, I see they changed the cam housings from what I have on my old 90. It appears that both cam housings are the same for the left and right cyl. on the 182, where they are different on the 90T. Oh well.

Bob Reeves · « **Reply #23 on:** August 21, 2011, 03:31:04 AM »

Quote from: Jim Kraft on August 20, 2011, 07:45:35 PM

Thanks for posting your experience Bob. I don't think there is any way to make the stock cam work in reverse as it would always open the intake valve first instead of the exhaust when running in reverse rotation.

Woke up this morning thinking how silly I was when I thought of using the stock cam DUH.....

Quote from: Martin Quartim on August 20, 2011, 08:05:47 PM

Hi Bob,

I have not got my parts yet, it takes for ever to clear customs down here. Any how, I had plan to work on this project after Brazilian Nationals in November.

The Diagram came from Horizon Hobby Tech Support. Could you make a diagram of how you made yours to work?

Looking forward to a flight report.

Martin

I wouldn't have a clue where the timing marks actually ended up, I set the cam gear in position by installing the intake pushrod and rotated it to where I just detected it starting to move (opening the intake valve), then positioned the crank to the same location as the one in the 56, except on the other side of the case. Set the cam housing in place and double checked that the intake was opening at exactly the same crank position as the sample engine. I had to move it a couple teeth from my first stab to get it right.

When I do the 56 I'll try to get a photo of at least the crank position. If you look at the stock engine with the back plate removed you can see this crank position (intake just starting to open) is about 10:00-10:30 on a stock engine and 1:30-2:00 with the reverse cam. The cylinder head with the piston can be removed by sliping the rod off the crank pin with the piston still in the cylinder. This makes it much easier to set the cam housing in place without accidently moving the cam gear position.

Bob Reeves · « **Reply #24 on:** August 22, 2011, 06:56:11 AM »

Wow! must be a bunch of people jumped on the band waggon, just went to order another 182TD34 cam gear for my other 62 and they are now on back order. Come on guys fess up, who'-s building reverse Saitos?

Allan Perret · « **Reply #25 on:** August 22, 2011, 07:15:35 AM »

I have a 56 and 62, so I ordered a reverse cam for each back when I first saw this post. Got the 62 cam but the 56 cam was back ordered.
Over the winter I plan to build a Ringmaster-1000. I plan to set up front end with aluminum mounting plate to try several engine options, one of which will be the 62. Figured by the time I am ready you will have this reverse thing all figured out.

Mike Callas · « **Reply #26 on:** August 22, 2011, 10:28:48 PM »

Quote from: Bob Reeves on August 22, 2011, 06:56:11 AM

Wow! must be a bunch of people jumped on the band waggon, just went to order another 182TD34 cam gear for my other 62 and they are now on back order. Come on guys fess up, who'-s building reverse Saitos?

I propose we call this configuration Otias!

Martin Quartim · « **Reply #27 on:** August 22, 2011, 10:55:21 PM »

I am writing Horizon claming sales comission

I also hope you guys see how good JXF props works.

Martin

Bob Reeves · « **Reply #28 on:** August 23, 2011, 07:37:04 AM »

Quote from: Mike Callas on August 22, 2011, 10:28:48 PM

I propose we call this configuration Otias!

Don't get it, please explain Otias?

I'm going to send TrueTurn a couple of the JFX props so they can create the CNC code to cut the slots in spinners. If this works out as I hope I'll be changing over a couple of my ships and will need new spinners. Test flights will be this coming weekend with the 62.

Mike Callas · « **Reply #29 on:** August 23, 2011, 06:03:13 PM »

Quote from: Bob Reeves on August 23, 2011, 07:37:04 AM

Don't get it, please explain Otias?

I'm going to send TrueTurn a couple of the JFX props so they can create the CNC code to cut the slots in spinners. If this works out as I hope I'll be changing over a couple of my ships and will need new spinners. Test flights will be this coming weekend with the 62.

That's Saito backwards.
OK, bad attempt at 4 stroke humor. But in my defense, it was a late night yesterday.
Looking forward to reading the results of your testing Bob!

Thanks

Mike

Bob Reeves · « **Reply #30 on:** August 24, 2011, 10:49:22 AM »

Now I get it, actually that's pretty cool... We dub the "The Otias mod"

Bob Reeves · « **Reply #31 on:** August 26, 2011, 08:27:41 AM »

After putting a couple test flights on the Somethin'Extra yesterday I'm not real sure what I'm looking for in flight performance. The big problem is I haven't flow the Somethin'Xtra in 3 years and about all I remember is I wasn't happy with something about the way it flew. One thing I did notice that may or may not have anything to do with reversing the engine is I had more line tension than I wanted or needed. Hoping I'll get in a few full patterns with it this weekend in diecent air and I'll have a better idea of where in the pattern it helps. Must be some reason all the electric guys are running reverse motors.

Bob Reeves · « **Reply #32 on:** August 28, 2011, 05:50:04 AM »

Yesterday Joe Gilbert and I were able to get a couple flights each on the Somethin'Xtra in good air. The reverse rotation 62 has completely transformed what Joe and I both remembered as a dog into a pretty darn good stunt ship. It still has a few minor trim issues but I wouldn't be a bit hesitant to fly it in competition as it sets right now. The standard Glow JFX 13-6 prop is working as well as anything I've tried on a 4 stroke and would recommend it to anyone. Today we are going to put a few more trim flights on it and just for grins I want to try the JFX 13-6 electric prop.

I'm really looking forward to putting the reverse 62 in the Latency. Today's flights will determin which JFX prop(s) I send to Tru-Turn for spinners. Once I have a spinner I can switch the 62 into the Latency and start working on a 56 for the Somethin'Xtra...

As soon as Horizon has more cam gears I'll switch my spare 62 and order gears for all my 56s. I see no reason not to switch everything I can over to reverse rotation, just wished they had a cam for the 40.

Dennis Adamisin · « **Reply #33 on:** August 28, 2011, 09:57:38 PM »

Quote from: Bob Reeves on August 26, 2011, 08:27:41 AM

One thing I did notice that may or may not have anything to do with reversing the engine is I had more line tension than I wanted or needed.

WELCOME to the world of the lefty handed props! Wait till you experience the difference in line tension in the top of the Vertical & Hourglass, plus the 3rd leaf of the Clover... Oh yeah, start thinkig about sliding the leadouts forward and removing all the rudder and engine offset.

BTW are you still able to do back to back flights with the Pusher engine and the tractor engine? That would help CLEARLY show if/what differences & advantages you have achieved.

This is a HECK of a project and I am really glad to see it (apparently) panning out for you.

BTW, Fox used to make LH cranks for the 35. I went looking awhile back but did not find any. Now I do not want one anymore, but SOMEONE ELSE might want to try that mod in a Fox.

Chris Wilson · « **Reply #34 on:** August 28, 2011, 10:50:05 PM »

Quote from: Dennis Adamisin on August 28, 2011, 09:57:38 PM

......... but SOMEONE ELSE might want to try that mod in a Fox.

Hmmm, I have heard from a friend who has a Fox 120 twin that is basically a horizontally opposed two stroke engine that is two completely separate and mirror reversed engines on a common crank.

So in effect one half of this twin will throw the crank case charge into the transfer port and the other half away from it.

The half that gets its charge throw into the transfer runs fine but the other half over heats markedly and must be richened up to compensate.

So logically, if you were in reverse run a Fox 35 you would be in for the same symptoms - now who wants to richen a Fox beyond what it runs at?

I wouldn't mind reverse running a more symmetrical engine though.

Douglas Ames · « **Reply #35 on:** August 29, 2011, 05:32:21 AM »

Quote from: Chris Wilson on August 28, 2011, 10:50:05 PM

Hmmm, I have heard from a friend who has a Fox 120 twin that is basically a horizontally opposed two stroke engine that is two completely separate and mirror reversed engines on a common crank.

So in effect one half of this twin will throw the crank case charge into the transfer port and the other half away from it.

The half that gets its charge throw into the transfer runs fine but the other half over heats markedly and must be richened up to compensate.

So logically, if you were in reverse run a Fox 35 you would be in for the same symptoms - now who wants to richen a Fox beyond what it runs at?
I wouldn't mind reverse running a more symmetrical engine though.

Your logic is flawed. A reverse 2-stroke crank would simply have the intake port machined on the "other side" of the crank pin for reverse running...on a single cyl. engine.

Bob Reeves · « **Reply #36 on:** August 29, 2011, 07:49:22 AM »

I heard about several two stroke engines with reverse cranks (Nelsons, Foxes) and none of them require anything but replacing the crank. Haven't analyzed how it might work but it does and with the ports in the same location. Reverse Nelsons are king in carrier if you can afford and find one.

Now back to 4 strokes...

Dennis,

Electric does still have a bit of an advantage as reversing the engine is a simple matter of switching wires. Flying back to back flights with a reverse/standard Saito would be a pretty good undertaking as you would either need to swap engines or worse replace the cam. Don't think that is going to happen, at least not in Oklahoma

Speaking of overhead turns, when I built the Latency I added all the pieces to be able to install a Rabe rudder and was just about to try it when this reverse stuff came up. It has always felt just a bit loose on overhead outside turns and felt the Rabe Rudder was worth a try. Now don't believe it will be needed

Chris Wilson · « **Reply #37 on:** August 29, 2011, 04:57:50 PM »

Quote from: Douglas Ames on August 29, 2011, 05:32:21 AM

Your logic is flawed. A reverse 2-stroke crank would simply have the intake port machined on the "other side" of the crank pin for reverse running...on a single cyl. engine.

Hi again Doug,
How is my logic flawed mate? The subject at hand was a Fox 35, in normal rotation the crank feeds the transfer port by acting as a slinger but with a reverse rotation crank it does not and you would not notice the difference unless you did back to back testing. The most perfect example I could think of was quoting ye olde Fox 120 twin.

Do you mean that a reverse crank engine needs to have its ports machined on the other side in order to run the same? I would agree.

Thanks.

Bob Reeves · « **Reply #38 on:** September 11, 2011, 04:53:10 AM »

Huston we have a problem.....

Was able to put several flights on the Latency with the reverse rotation 62 and I believe the largest challenge is going to be finding a prop that will work. I had to crank the RPM down to 7700 with the JFX 13-6 to get reasonable lap times and the Saito just isn't happy at that RPM. Vibration is noticeably higher and the settings are way too critical to be consistant. I've found over the years that the 56/62's are most comfortable and work well in the 8100-8400 range and I couldn't get there without the lap times being way too fast. JFX doesn't make a reverse rotation 13-5 and I'm not a prop maker so not sure where to go from here.

It is interesting that a Rev-Up 13-7 (measured pitch about 6.5) will pull the Latency at 5 second laps with the engine turning 8200 and a 13-5.5 carbon 3 blade gets there at 8400 but with the JFX 13-6 I had to go down to 7700. I don't yet have a way to measure the pitch of the JFX so not real sure what it actually is.

On the plus side even with somewhat questionable engine runs I liked what I saw and felt flying with the reverse rotation engine. Two most notable and obvious improvements are at the top of the vertical eight and the top of the hour glass. Guess for now it's back to the drawing board, I'll put the reverse engine back in the Somethin'Extra and go back to the stock 62 in the Latency.

Douglas Ames · « **Reply #39 on:** September 11, 2011, 03:32:53 PM »

That's showin' ya how efficient that JFX prop is. You could experiment by trimming the dia. if you don't mind sacrificing a prop. That might get your revs up?

Martin Quartim · « **Reply #40 on:** September 11, 2011, 10:31:26 PM »

Bob,

Have you mesured the actual pitch of the prop? TIt is not common for JXF but very possible that the actual pitch is way off. Do you have other props of the same to try?

You can try 14x6 and if need cut to smaller diameter. The other option is Zinger, they have in all sizes , including a 13x5P

I believe it is possible to special order a 13x5 Pusher from Himdel, also a 12 13 and 14 3 blades pusher props in any pitch.

The vibration should not be more or less the normal rotation, is there any possibility you got reverse cam gear installed a bit off ?

Good luck my friend!

Martin

Dennis Toth · « **Reply #41 on:** September 12, 2011, 10:30:50 AM »

Guys,
While you are changing things around is there any way to adjust the cam timing to allow reverse rotation and to switch the intake and exhaust ports to allow the muffler to come out the back of the motor and route the intake to the side? My one problem with the current port layout is to have an ugly muffler hanging off the side of the fuse. If we could switch the ports we could have the muffler exit through the bottom of the cowl and keep a very clean fuse view.

Best, DennisT

Douglas Ames · « **Reply #42 on:** September 12, 2011, 03:57:44 PM »

Not intending to Hijack this thread...but it is possible to run a flex exhaust on a Saito .56 or larger out the back w/ 90 deg. + flex pipe. (M10x1.0) Haven't found anything for a .40 yet.

Chris Wilson · « **Reply #43 on:** September 12, 2011, 04:53:59 PM »

Quote from: Dennis Toth on September 12, 2011, 10:30:50 AM

Guys,
While you are changing things around is there any way to adjust the cam timing to allow reverse rotation and to switch the intake and exhaust ports to allow the muffler to come out the back of the motor and route the intake to the side? My one problem with the current port layout is to have an ugly muffler hanging off the side of the fuse. If we could switch the ports we could have the muffler exit through the bottom of the cowl and keep a very clean fuse view.

Best, DennisT

Possibly you could switch the push rod tube around so that the timing changes over but aren't the valves different sizes also?

That and the swirl in the combustion chamber might be ruined.

Dennis Toth · « **Reply #44 on:** September 12, 2011, 07:18:49 PM »

Chris,
From the ones I've looked at both valves are the same. I don't think there would be much difference in swirl in the combustion chamber. I think the Saito's are unique in that the intake tube could work in either port.

Best, Dennis

Chris Wilson · « **Reply #45 on:** September 12, 2011, 09:33:19 PM »

Quote from: Dennis Toth on September 12, 2011, 07:18:49 PM

Chris,
From the ones I've looked at both valves are the same. I don't think there would be much difference in swirl in the combustion chamber. I think the Saito's are unique in that the intake tube could work in either port.

Best, Dennis

Same diameter and metal composition? Ok then.

Dennis Toth · « **Reply #46 on:** September 13, 2011, 02:13:14 PM »

Doug,
Where did you get the 90 deg exhaust pipe from? How heavy is it comprared to the regular muffler?

Best, DennisT

Douglas Ames · « **Reply #47 on:** September 13, 2011, 03:00:22 PM »

That photo is from Saito! I'm thinking of doing this to my .40 but not sure what's available for that engine.

http://saito-engines.info/mufflers.html

Douglas Ames · « **Reply #48 on:** September 13, 2011, 03:03:04 PM »

Quote from: Chris Wilson on September 12, 2011, 04:53:59 PM

Possibly you could switch the push rod tube around so that the timing changes over but aren't the valves different sizes also?

That and the swirl in the combustion chamber might be ruined.

Don't think the pushrods or tubes are long enough to criss-cross, plus tappet angle.

Bob Reeves · « **Reply #49 on:** September 13, 2011, 03:59:27 PM »

Quote from: Douglas Ames on September 13, 2011, 03:00:22 PM

That photo is from Saito! I'm thinking of doing this to my .40 but not sure what's available for that engine.

http://saito-engines.info/mufflers.html

Not that I could find so I made my own.. Not something I want to do again but it turned out pretty nice.

Need to be careful, it was some time ago when I was looking but seem to remember the 56/62 has a smaller exhaust port thread than the 72. I could find just about anything one would want for the 72 but not hardly anything for the 56 so I made the tools to bend the pipe for the 56/62 to the angle I wanted.