the benz master

Went ahead to calculate the timing with these measures. With stock stroke it's 110/188 = 39 blowdown... Makes absolutely no sense at all. Transfers need to be raised at least 10-12deg to yield usable timing. This means raising the transfer ports about 1,8 to 2,1 mm. this would give 120-122/188 and 33-34 deg of blowdown. With a 4mm stroker crank = 118 /189.5 with 35.75 blowdown. Timing makes a lot more sense. stock cylinders measured out to 113/180... seems a bit low compared to what i've read around here.

Just got a set at like 65% off on amazon and decided to look into port timing more closely before using it because a lot of people don't seem to like it. Made the port map and compared to stock cylinders (picture bellow) So basically i think this port timing was never meant to be used with stock stroke. Piston will cover about 2mm of the bottom of the transfer ports when at BDC instead of sitting flush. So the transfer ports are 13% larger than stock but piston is blocking like 16% of the ports so you end up with less area than a stock cylinder... and with the lower port timing well it just won't work on stock crank unless you change the porting/timing. I think the slightly lower transfer port must work out ok with a stroker crank, will have to calculate exact timing it gives out with both strokes. So the facts: Transfer ports 13% more area than stock Intake ports are 48% more area than stock Exhaust port (s) have 42% more area than stock Lots of material in the cylinder for porting In 392cc trim this is not bolt on, needs some serious work to make right You need a +4 stroker crank to make use of these transfer port properly Casting quality is not good, lots of porosity in the aluminum so lots of porosity in the nikasil coating too. I might get one of the two cylinders re plated before using it. (must be why it was sooo cheap) At 325$ it was a great deal, but anyone paying full price is def getting ripped off and not getting a well engineered/manufactured kit. D