tearing into my simonized 372xp

[SCTREEGUY]

We're any ports widened? Intake lowered? Transfers raised?

I don't think so brad.

Make sure it is the XP piston. The regular 268 piston is also 50mm but it is not windowed. There is a difference.

It is the windowed piston.

Why not send it to someone and cut the chamber? Then next time no worry about getting a pop up cut.

To me it seems much easier to get the piston cut and leave the cylinder alone.

 

[nmurph]

Was the base cut?

The question that hasn't be asked is this: is it a ported saw if there was no grinding done?

 

[SCTREEGUY]

The base appears to be the same as new 1. So do the intake and exhaust ports but the intake has a slightly polished look to it.

 

[SCTREEGUY]

The piston is much lighter than the new 1.

 

[Trx250r180]

I really don't think anything is done to the cylinder. I slid a piston pin into both pistons at the same time to see the difference in pin location. The machined down portion of the piston that was in it is almost 1mm higher than the top of the new 1 then there is a 1mm popup. Its hard to get an accurate measurement of the 2 because the skirts are totally different. I ordered a new oem 268 piston last night and I'm gonna take both to the machine shop and get them to copy it then put it back together with the new cylinder.

Have them check the bottom of the piston skirts also ,on my saw the bottom of the skirt was machined to adjust the timing on the intake side

Simonizer is a member of the site ,i am sure he has replacement pistons ready to go ,would not hurt to send him a pm

 

[blsnelling]

Was the base cut?

The question that hasn't be asked is this: is it a ported saw if there was no grinding done?

No. Modified, but not ported.

 

[SawTroll]

Yes, a 272 is 52mm. The 268 was a 50mm and I believe some of those were CP saws(?).

The SE, XP and 268 Specials were CP.

 

[SCTREEGUY]

Have them check the bottom of the piston skirts also ,on my saw the bottom of the skirt was machined to adjust the timing on the intake side

Simonizer is a member of the site ,i am sure he has replacement pistons ready to go ,would not hurt to send him a pm

I thought about it but didn't want him to see this post and think I was complaining. I really do like this 372.

 

[SawTroll]

The SE, XP and 268 Specials were CP.

I forgot to say that two different piston designs were used in the 266SE saws - all the CP pistons were not the same. As I recall it, it is the second design that was of the same basic design as the one in this 372xp.

 

[tlandrum]

ive used the 266 piston in a lot of my builds back in the day.

 

[nmurph]

I forgot to say that two different piston designs were used in the 266SE saws - all the CP pistons were not the same. As I recall it, it is the second design that was of the same basic design as the one in this 372xp.

When was the thin ring 266 version made?

 

[Rx7man]

If this Simon fellow lowered the jug 1mm, the intake timing would naturally have increased, and the exhaust decreased (meaning increased power stroke time), though the cut on the piston would pretty much nullify that. From my little bit of experience, that can wake the saw up.. Perhaps someone asked him to do it on a budget? basically a Stage 1 mod.
Whatever was done with it seems to have made you happy anyhow

 

[Trx250r180]

If this Simon fellow lowered the jug 1mm, the intake timing would naturally have increased, and the exhaust decreased (meaning increased power stroke time), though the cut on the piston would pretty much nullify that. From my little bit of experience, that can wake the saw up.. Perhaps someone asked him to do it on a budget? basically a Stage 1 mod.
Whatever was done with it seems to have made you happy anyhow

things were done differently 5 years ago than they are today ,not that either is right or wrong ,just done different

 

[Rx7man]

things were done differently 5 years ago than they are today ,not that either is right or wrong ,just done different

Exactly.. and every builder has unique things they do, and every customer has different wishes too

 

[old-cat]

I much prefer the term "performance upgrade", than ported.

 

[SawTroll]

When was the thin ring 266 version made?

Sorry, I don't know that.

 

[drf255]

I'm thoroughly confused at this point. Can't tell which piston is which in your first postings.

I don't think you can visually notice a .020 base cut on a cylinder if it's done right.

Once you have a custom saw that someone's monkeyed with, all bets are off.

You're gonna have to find that same diameter, pin size and compression height piston and put the saw together. Your gonna have to measure squish.

My bet is that if you find the stock piston, it will be a head slapper without the popup cut.

If you match it up and can measure, someone here will do that machine work for you at a fair price. That is certain.

 

[nmurph]

Sorry, I don't know that.

There is a Hv factoid that Niko doesn't know, what good are you then???

 

[SawTroll]

There is a Hv factoid that Niko doesn't know, what good are you then???

Well - I wasn't there when it happened - but a fair guess would be the early years (like before 1985)?

There is a lot I don't know about that model Family - and Huskys use of thin rings in general....

 

[weimedog]

Timing and compression. Humm, imagine that. Does it matter how you get there? Lighter piston=snappier throttle response? Seems like an intelligent approach. Good "bang per buck" and makes for a happy customer.