spacer plate?

[woodsracer144]

ok I know about the base plates but what if you ran a spacer plate between your head and the cylinder? It would make the voulme of the cylinder larger and I know it would effect port timing but at the same time, theres less cost due to the amount of alum being use and theres more studs pulling down to hold it tight.

just something I was thinking about tonight when I was out by my R

[C-LEIGH RACING]

Put your thinking cap on & think about what all is going on in that area where your thinking of putting that spacer.

What you have in your mind, is something that should have been decided before the first carbide cutter ever touch the cylinder casting.
Because it could have been machined proper to start with not to even have to use a base spacer plate.

That is one thing I've never understood, why machine a 250R aftermarket cylinder wrong, when they all know full well an 85/86 model style piston is to be used & a long rod crankshaft. Why machine it so a spacer plate is even needed.

You can no longer get the Honda OEM short rod crank & 9 out of 10 engines have the long rod crank, so why machine the cylinders wrong.
Neil

[bloodswet&gears]

Originally posted by C-LEIGH RACING
Put your thinking cap on & think about what all is going on in that area where your thinking of putting that spacer.

What you have in your mind, is something that should have been decided before the first carbide cutter ever touch the cylinder casting.
Because it could have been machined proper to start with not to even have to use a base spacer plate.

That is one thing I've never understood, why machine a 250R aftermarket cylinder wrong, when they all know full well an 85/86 model style piston is to be used & a long rod crankshaft. Why machine it so a spacer plate is even needed.

You can no longer get the Honda OEM short rod crank & 9 out of 10 engines have the long rod crank, so why machine the cylinders wrong.
Neil I think people see the word long in "long crank" and think the stroke will be longer.

As far as putting a spacer at the top, the rings would hang at the spacer or you would lose your squish band or loose compression one.

[woodsracer144]

I know what all goes on up top but i've seen head/domes that are milled out and the top of the piston runs up in to them a little bit. I know pinit had a sparks 265PV that had the piston running out the top of the cylinder, as far as how much it came out Im not sure on that. I've also heard of people not running a top piston ring.

just something I thought of...

[C-LEIGH RACING]

Do you know what size piston pinit had in that 265PV.

I've had some engines, the dome was cut so the piston could run up in it, but thats not how it is suppose to be done.
That is just an easier way to get the engine build completed.

Fact still remains, if the cylinder castings were machined right to begin with, a spacer plate would not be needed.

All of the Pro-x & ESR cylinders, are machined just like as if all were going to be mounted on a bottom end with a short rod crankshaft.
Neil

[bloodswet&gears]

You would also have to move the ports up the same amount as the thickness of your spacer. Or you would have to notch the piston at the top by exh. port for exh. timing and maybe other places like intake side at the bottom.

Not trying to discourage you. I like the way you think.

What was hondas reason for getting away from the 85/86 style? I like those the best!!

[woodsracer144]

Originally posted by C-LEIGH RACING
Do you know what size piston pinit had in that 265PV.

I've had some engines, the dome was cut so the piston could run up in it, but thats not how it is suppose to be done.
That is just an easier way to get the engine build completed.

Fact still remains, if the cylinder castings were machined right to begin with, a spacer plate would not be needed.

All of the Pro-x & ESR cylinders, are machined just like as if all were going to be mounted on a bottom end with a short rod crankshaft.
Neil

No, I don't know what size it was. I think he still has it.

not to start a piss fight but I see loads of people running base plates with pro x cylinders. I had a 265 ported by FTZ that was a base plate motor. you make it seem like if you run a bace plate your running it wrong.

this is what I know at the end of the day I have a hot rods C.K. 109 rod. I've always ran a spacer plate. one was ona 88 89 style oe cylinder ( dont remember off had what piston it was it was a LRD ported cyl.) the other was a 85 ATC stock bore unported with a CR piston. (66.4mm) I also tried several other bike pistons ( gas gas KX) mainly because I got them for free... long story behind it....

I just thought due less material being used and stuff why wouldnt it work. hell if somebody can take a Rotax cylinder and run it on a trx bottom end i'd think you could run a spacer plate up top...

[C-LEIGH RACING]

I'm not saying using a spacer plate under the cylinders wrong. With a stock OEM Honda TRX cylinder, if you start changing cranks & pistons around, only way you can do it is with a base spacer plate.

Now the idea you have of a spacer plate on the deck of a cylinder, it can be done, but would be best if it was welded in place & then all areas machined back into shape.

If the cylinder casting was a sleeved cylinder, then the sleeve would need to be removed, the casting welded in at the top where the sleeve lip is located at, then the inside top of spacer machined for the sleeve lip & new sleeve installed.

Of course with the spacer being in placed at the top of the cylinder, it would take a new sleeve with the port windows cut in a different place lower down in the sleeve.

Now if you were putting the spacer at the top of a nikisal bore cylinder, would just be a mater of sending the cylinder to get the plating removed from the bore, weld the spacer in place, machine the welding into shape & then send back to get the bore re-plated.

Welded & machined back into shape, by doing it like that, the area where you added the spacer plate, it would be nikisal plated & the rings culd run in that added spacer plate area with no problem.

I know what your thinking of doing, but your somehow going to have to figure out how you will seal that spacer plate on both sides.
The best way would be to weld the spacer in place, machine the weld joints & then you only got one area to seal with a gasket or o ring.

I've seen quite a few cylinders with spacer plate on the top, sleeper deal, but who evers looking at it would really have to know what the cylinder looked like stock to tell it was in place.

You ever heard of a 112cc, 85cc dirt bike engine & you look at it & couldnt see anything changed on it.
Neil

[woodsracer144]

I thought those 112's were like a RM100 cyl and a stroker. I had a RM100 but sold it this last summer.

main reason I thought of it was on my polanda build... I'm waiting on my base plate to be built and I have the cylinder sitting on the cases so stuff dont get in to crank case and the piston is just sitting high enough so it doesn't pop a ring out with he head sitting on top of that. and I was like " hell why not just put it on top of it? "

but thats way more work to put it on top....

[Honda 250r 001]

Originally posted by C-LEIGH RACING
That is one thing I've never understood, why machine a 250R aftermarket cylinder wrong, when they all know full well an 85/86 model style piston is to be used & a long rod crankshaft. Why machine it so a spacer plate is even needed.

You can no longer get the Honda OEM short rod crank & 9 out of 10 engines have the long rod crank, so why machine the cylinders wrong.
Neil

Atleast ESR has decided to machine cases with the spacer plate added into them already, making the spacer plate unnecessary with their set up, which might be easier to notice vs a cylinder with a spacer plate machined into it.

[C-LEIGH RACING]

Woods,
You gona have to put that spacer plate, under that Polaris jug anyways, because of that little bit of sleeve sticking out.

You done got the cases finished, those 4 holes filled & the case bored out & studs moved.
Neil