Any dolmar experts??

[S&S_Work_Saws]

First off I'm sorry if this is posted in the wrong place. If not allowed here feel free to move it or delete.

So this weekends score made me happier then any in recent memory. I was contacted my a logger who had a pile of Dolmar 7910 saws and a bunch of parts.
While I was there I was also able to purchase a Stihl 462C very cheap but it needs a new clutch side case and that's a whole different ball of wax.

Alright, back on topic here...
I've been sifting through all the parts and trying to pick out the better of the parts to build myself a saw to keep and the rest I'll assemble and sell finished and running or as is for projects.
I've already noticed that there is a difference in the pistons and cylinder. I never knew there was different variations of 7910 cylinder or what is going on here?? I have 4 cylinders and they are all the same bore size and all have the decomp in the top and the weird SLR channel in the exhaust ports.
I have 2 that the upper transfers are very close to being inline with the intake ports and the other 2 the transfers aren't as wide but the exhaust port on those look a little bigger.

so which is the better just to start with? The wider transfers and smaller exhaust port or the narrower transfers?

Thank you guys for any advice you can offer

 

[Shane¹]

Did you measure the bore. First picture almost looks like 50mm.7310 cylinder the groove around the outside looks thicker. Ps I would be interested in parts if you start selling off things

 

[Czed]

@davidwyby

 

[S&S_Work_Saws]

Did you measure the bore. First picture almost looks like 50mm.7310 cylinder the groove around the outside looks thicker. Ps I would be interested in parts if you start selling off things

They are all 4 mahle 52mm cylinders. Just to be sure I double checked all of them with my caliper and their all the same....52mm

As soon as I can get myself one put together I'll be open to offers on the remaining parts.

 

[stihl livin]

@Wilhelm
@ajschainsaws

 

[Gullet]

^^^^ THIS!

 

[Ketchup]

I would go with the cylinder that looks like it is scavenging the best. There will be less residue in the combustion chamber. Especially on the Intake side. The second of the two pictured looks better.

 

[S&S_Work_Saws]

I would go with the cylinder that looks like it is scavenging the best. There will be less residue in the combustion chamber. Especially on the Intake side. The second of the two pictured looks better.

It's pretty hard to tell with some of these. There is either 4 or 5 lower end assemblies and 2 or 3 of them have the pto side crankshaft snapped off at the clutch with pretty low hours on them. In the morning I'll snap some better pics of the chamber. I guess I could also check the timing on both designs and see how different that way.

 

[Ketchup]

It's pretty hard to tell with some of these. There is either 4 or 5 lower end assemblies and 2 or 3 of them have the pto side crankshaft snapped off at the clutch with pretty low hours on them. In the morning I'll snap some better pics of the chamber. I guess I could also check the timing on both designs and see how different that way.

Timing would be good to know. Looking at the chamber doesn’t rule out several variables. Mix oil, run time, muffler style etc. But a jug that looks like it was running right is always a good sign. I don’t know 7900 well at all, but what I hear is the performance difference in cylinders isn’t large. Both those pictured look good.