LCGB Forums

Hi - has anybody quantified the benefits of matching the barrel to engine case?
Ie tangible before and after measurements
For example what would be the HP gain (or other benefit ) of this work?
Additionally are the any disadvantages?

The reason I ask is I am contemplating doing this work on my casing in my preparation for a new gt186 kit

Probably no difference, but blue printing involves a lot more than just matching the bottom of the barrel to the engine casing gasket face. All the tolerances need to be optimised, especially the squish.

If you haven't read the recent articles in Scootering on getting the best out of an SIL engine, then this is getting closer to what I understand as blue printing. The results are really surprising.

Probably no difference,

+1

On holiday at the mo so I'll read the scootering article when I get back.
Understand about the squish' importance.

I'll still be interested if anyone has before and after info

I match everything from inlet to transfers to piston tolerance and ring gap, compression ratio, squish but I have never had a starting reference point. My opinion is that yes it does make a difference.

Eden wrote:

Probably no difference,

You seem surprised.

I figure that unless you are opening up the transfers at the bottom of the the barrel, and then matching this to the crankcase gasket face, then simply taking out a small step on a standard port will make little difference. After all, at that location, the fresh charge doesn't have much velocity or direction: it only once the fresh charge is in the transfers that it acquires these.

Having said that, I always match the transfers to the crankcase gasket face because it is just one of those things you do.