Welcome to Club SAITO !
03-26-2019, 03:47 PM
03-26-2019, 03:47 PM
Senior Member
03-26-2019, 05:02 PM
03-27-2019, 02:41 AM
Yup
the 150GK did not fly. Even after I told her it was an “S” She just said get that thing out of here. Jr thought it was cool but mama rules.
So after supper we built another 180HC. Will run that tonight.
the 150GK did not fly. Even after I told her it was an “S” She just said get that thing out of here. Jr thought it was cool but mama rules.
So after supper we built another 180HC. Will run that tonight.
Last edited by Captcrunch44; 03-27-2019 at 02:52 AM.
03-27-2019, 03:12 AM
Shortening Saito Pushrods
I will be removing material from the cylinder deck of the case on my fa82 to increase/optimize effective compression for use with 15% nitro. At some point I may need to shorten the pushrods to maintain proper pushrod/rocker arm geometry. I'm looking for advice on how to accomplish this without compromising the metal hardness and how one might go about reprofiling the tappet end of the pushrod after shortening it.
03-27-2019, 03:13 AM
Dave, I was going to try it as Gary said, I would think it should work, because these valves came with my regulators (I just need a couple more), they are used with the OS Heli engine regulators to hold the tank pressure from going back into the crank case, and knowing a 4 stroke should have more crank case pressure than a 2 stroke I would think they would work on a Saito too
Jim
Jim
Still want me to send a pair or are you going with Dave's source?
Just let me know...
03-27-2019, 03:27 AM
I will be removing material from the cylinder deck of the case on my fa82 to increase/optimize effective compression for use with 15% nitro. At some point I may need to shorten the pushrods to maintain proper pushrod/rocker arm geometry. I'm looking for advice on how to accomplish this without compromising the metal hardness and how one might go about reprofiling the tappet end of the pushrod after shortening it.
03-27-2019, 03:30 AM
On a 180 with longer pushrods yeah maybe it wouldn't affect the geometry much. On an 82 with shorter pushrods it might. I attend to make the sweep nuetral (90°) at mid lift or at the very least duplicate the swept motion as designed by saito.
Last edited by Glowgeek; 03-27-2019 at 03:36 AM.
03-27-2019, 03:45 AM
You’re not changing the valve train. All those parts would not be affected. Even on the shorter 82.
03-27-2019, 03:57 AM
I suppose you're right, the rocker shaft is in a fixed location. Cutting pushrods is probably a non-issue too if the lash adjuster remains within adjustable range. I'm an over thinker with a brain deficit.
03-27-2019, 04:14 AM
03-27-2019, 04:20 AM
Senior Member
Will that have a significant effect on valve train efficiency? Maybe, maybe not.
How are you determining how much to reduce the deck height?
Do you know the existing combustion chamber volume?
Have you checked the existing piston/valve/head deck clearances?
03-27-2019, 04:23 AM
Senior Member
03-27-2019, 04:53 AM
Yes, it is the same as just changing the push rods out. You will just have to maybe change the lash as long as he does not mil off too much of the base of the cylinder head. I guess when I say geometry I mean within reason of what he is trying to do. I changed a cam in a 5.7 hemi and I considered two options either one milling the heads or getting 6.1 hemi rods. I chose 6.1 rods. Did not have to mess with the lash or alter the current setup of the geometry. Ether way everything was in spec and I would not have had to adjust the valvetrain. So that is what I mean in this case I would think he will be in spec to not completely alter the geometry of the factory setup.
03-27-2019, 04:59 AM
I only have an idea where the CR will end up when optimized for 15% nitro. Probably somewhere between 10:1 to 12:1 but that's just based on what I've read around the forums.
Determining initial CR will dictate how much I deck the case and I will probably remove material .010" at a time until I see no more peak rpm gain with an apc 14x6 prop. Once that is established a .005" brass shim will be added back as a safety margin to ward off detonation.
LOTS OF EDITS ABOVE and if I'm on crack someone will straighten me out I hope.
Last edited by Glowgeek; 03-27-2019 at 05:24 AM.
03-27-2019, 05:31 AM
03-27-2019, 07:13 AM
Senior Member
The adjusting screw must then be backed out to make up for the "longer" pushrod. This does slightly change the rocker arm geometry.
Visualize it as bending a straight line between the rocker/valve stem interface and the rocker/pushrod interface
Is it significant? Not really, as long as it is not extreme. The 1st issue that would probably arise is not having enough threads in the rocker for the required adjustment.
FA-120/150/180 all use the same pushrod.
Last edited by SrTelemaster150; 03-27-2019 at 07:22 AM.
03-27-2019, 07:21 AM
Senior Member
Yes, it is the same as just changing the push rods out. You will just have to maybe change the lash as long as he does not mil off too much of the base of the cylinder head. I guess when I say geometry I mean within reason of what he is trying to do. I changed a cam in a 5.7 hemi and I considered two options either one milling the heads or getting 6.1 hemi rods. I chose 6.1 rods. Did not have to mess with the lash or alter the current setup of the geometry. Ether way everything was in spec and I would not have had to adjust the valvetrain. So that is what I mean in this case I would think he will be in spec to not completely alter the geometry of the factory setup.
I know a little bit abut wringing more power out of those roo.
Stock rotating assembly MDS still enabled 26 MPG on the highway, 4300# at the line. Driven to the track, sometimes as much as 900 miles one way.
That was N/A, this is with a 125 shot of nitrous that ran out just as I hit the traps..
03-27-2019, 09:27 AM
My Feedback: (1)
Jim
Last edited by the Wasp; 03-27-2019 at 09:30 AM.
03-27-2019, 09:35 AM
My Feedback: (1)
Cutting pushrods is probably a non-issue too if the lash adjuster remains within adjustable range
Jim
Last edited by the Wasp; 03-27-2019 at 09:56 AM.