I bought what was supposed to be a Flannery ported XCR 800 motor, once I took delivery it turned out to be an Ultra big bore with XCR jugs on it, a shim kit, and modified HTG heads. They appear to have been ported, but I don't think it was Flannery that did the job.

The jugs all have been "engraved" with mag, C, and pto, and also what I assume are the initials of the person that did the porting....CSR. Anybody have any ideas?

Crank Shop Racing??????

Just a guess.

i think i would be pissed, ported and a shim kit, never heard of that being done, i know doug doesnt think much of the shim kits, if he, or anyone , ported the jugs there would be no need for the shims .

The engravings are probably so that the jugs didnt get mixed up. Mag will probably be magneto side, C will be center, and PTO will be output PTO side.

Yep, definately not a happy camper. For what I paid for it the deal would have been sweet if it actually was a low mileage flannery ported xcr 800 motor. As it sits, I'll be lucky to get my money back out of it. If I do get my cash back no harm done.

I was wondering about that porting too....why would you port it AND mess around with a shim kit....the whole idea of the shim kit was to avoid the porting entirely.

I have emailed crankshop to see if that's how they mark jugs they have worked on. If they did the work that would be a good thing.

Sounds something like an htg kit....saw similar stuff by this description a buddy has worked with.

I really don't think The Crank Shop did those cylinders. I've had their stuff come in here and don't recall ever seeing those stampings.

Try calling Dynoport. They told me before they have and will port a motor with the shim kit, keeping the shim kit. Their reasoning was because the heads are already set up for it. I asked about the transfers being too high and the response I got was the clutching would just have to be a little more spot on with the higher transfers.

Makes sense if the shim kit is already there. However, IMO (with all due respect to DynoPort), the height of the transfers in relation to the upper edge of the exhaust port has a definite effect on cylinder filling at any particular rpm. Too close together, and you may not get maximum airflow/hp from the engine at higher rpms. I'm sure there's a fine line between proper coordination of pipe length, diameters, port layout, exhaust valve opening/closing, jetting and ignition timing. And on this engine, Polaris has done a fine job with the stock configuration. There must be sufficient time to dissipate spent exhaust before opening the transfers or some of the exhaust gases find their way down the transfers and fresh charge is blocked. The opening of the exhaust port sufficiently ahead of the transfers enables a period of "blowdown" before the transfers open. Engines set up to run on the trail at lower peak rpms may not be hurt much by higher transfers (in fact, might be helped), but higher rpm race engines probably will be. Lowering the transfer ports (not raising them with a shim) helps in this case according to Flannery. Consequently, the combustion pressure can to be dissipated sufficiently to allow MAXIMUM transfer of incoming fresh charge from the crankcase to the combustion chamber. I'm of the opinion, based on successfully racing my stock ported/piped 800 XCR against many modified 800 XCRs, that Polaris knows exactly what they were doing to get the outstanding broad range stock performance from this engine.