Hi All,
Quote from Dutch
""My new Thunder/Lightning Rods arrived today, (almost too fancy to hide inside the engine)and should have scales coming soon, so can start to play seriously.
The Torque settings are 40-43, a bit higher than I expected, .....? the rods fit the cutaways, which are a bit skew-whiff, and I figure if I just square them up should be ok, figuring if there's any more movement than that, there's a problem anyways!""
Following on from my last reply attached is a pic of the modified cylinder cutaways for the MAP cycle conrods
Dutch's Lightning rods will be almost identical I believe ???
The modded cutaways are 25.4mm wide and 17+mm deep (1" x 11/16").
Dutch,
The added balancing holes on my crank are at the crankpin side (see previous pic)
Re torque settings, From some research here on the forum
The 40-43 ft/lb seem to be too high,and causes problems
28ft lbs was the figure recommended
It is also recommended to tighten and retorque several times to prestretch the bolts????
I was wondering if I drilled an alloy block and tapped to suit the bolts would this be a better bet than tightening the bolts into the rods to pre strench?????
In "Tuning for Speed" Irving says to consider the top half of the conrod as reciprocating weight (to be added to the piston weight,
If the crank and rod assembly are arranged with the big end of the crank at the 3 0clock position its easy enough to weigh the small end of the conrod
If/when Rocket Racer fits shorter rods will the cutaways need to be deeper?? unless pistons with a different pin position is used?? (must read the article??)
Back when I was considering options on building my SR engine I enquired about using Carrillo rods??
I was informed that this would require removal of the flywheel to mill away enough material from it on the crank pin side
Regards
John