Avon gearing - Printable Version +- Vintage Karting Forum (https://www.vintagekartforum.com) +-- Forum: Main forums (https://www.vintagekartforum.com/forumdisplay.php?fid=1) +--- Forum: General (https://www.vintagekartforum.com/forumdisplay.php?fid=2) +--- Thread: Avon gearing (/showthread.php?tid=1578) |
RE: Avon gearing - Doug Jorgensen - 07-18-2017 (07-18-2017, 07:35 AM)David Luciani Wrote: Jeff, RE: Avon gearing - Doug Jorgensen - 07-18-2017 Thanks Dave for the input...the MC-75 IS unmodified and I am trying to keep it era correct. I thought the 75 was more in the range of 125cc ? At Sandy Hook I was put in the 8.2 rear class, and got left in the dust on the corners...although I really didn't expect all that much being it was my first time out ever in a kart....I have been Drag Racing and restoring Corvettes most of my life, so I have the mechanics of it all down, I just want to be "somewhat" competitive, at the very least. I'm just trying to learn how all of it ties in. Back to the gearing...I'm thinking that at 6'2" and 250 lbs., it 's gonna take alot more than gearing....the kart runs real good, I ran 9-72 at Sandy Hook, but I understand all track are different as far as straights and corners. I have a few different axle sprockets, so I'll bring a few, ask a few questions, and I guess see what works best for me. But any advice is always helpful ! Thanks.....Doug RE: Avon gearing - steve miller - 07-18-2017 ..im not sure about a 75 but my 70 runs in the 8.2 class .. im still wondering about ur rear tires ..12" are they on 6" rims .. what blitz chassis you run ..the old long style ..?? or like f1000 style .. with them big tires you might need a 74 .. id have to guess you ride with us in historic if your not in 8.2 either way both unscored and great folks in each class ..woops 8.2 scored class this yr .. you will be surprised how much track time you,ll get ..its all about fun .. I ride in the rear in sidewinders with john P. we have the best time ..I pass him he pass me we laugh so hard passing each other see who pressure the other guy ..its fun and we are in the back not in any bodys way .. RE: Avon gearing - Doug Jorgensen - 07-18-2017 (07-18-2017, 08:28 PM)steve miller Wrote: ..im not sure about a 75 but my 70 runs in the 8.2 class ..Yes Steve, they are 12" tires on a 6" rim. To tell you the truth I really don't know exactly what chassis it is, it's from about 1964...as far as the long style, I wish..at 6'2" my knees are in my chest. Maybe someone on here who saw it at Sandy Hook might remember. I tried it on the street with a 76 gear, fairly quick off a start, and at about a 275 ft. it was still pulling at top end. When I was in 8.2 at Sandy Hook, if I'm not mistaken, it was scored. This is all very new to me, so I'm learning as I go, and trying to absorb everything. RE: Avon gearing - steve miller - 07-18-2017 ..biggest thing you gotta absorb is having fun .. Lol.. in vintage karting there are sooooo many good folks ..and there full of knowledge and willing to share .. yes ill bet you were in scored 8.2 parta the northeast deal ..few them guys are very fast .. you come to avon scotts event ...he will find a spot for you to ride if you don't wanna be in 8.2 scored .. is your kart same style as mine ..if so I cant belive you can ride it ..if it is you need rupp pedals give you about 4 more inches .. correction to my post 8.2 rear is scored at avon this yr.. as parta the northest shootout .. woops sorry .. RE: Avon gearing - David Luciani - 07-18-2017 ok doug, i should be sleeping but this is a fun thread. here's the general mcculloch specs bore and stroke Model - Bore Stroke Displacement MC2 - 2.165 x 1.635 = 6.05 MC5 - 2.125 x 1.375 = 4.9 MC6 - 2.125 x 1.500 = 5.3 MC7 - 2.165 x 1.635 = 6.05 MC8 & 9 - 2.165 x 1.635 = 6.05 MC10 - 2.125 x 1.500 = 5.3 MC20 - 2.125 x 1.635 = 5.8 MC30 - 2.165 x 1.635 = 6.05 MC40 & 45 - 2.165 x 1.635 = 6.05 MC70 - 2.217 x 1.835 = 7.08 MC75 - 2.250 x 1.835 = 7.29 MC49 - 2.125 x 1.375 = 4.9 MC90,91,2,3 - 2.165 x 1.635 = 6.05 MC100 - 2.250 x 1.835 = 7.29 MC101 - 2.280 x 1.835 = 7.5 ok so technically you have a bigger motor than a mc91 if you only take bore and stroke into account. but there is something else to consider and your motor experience will help. you have a motor with only six intake ports. that seems pretty good till you consider all mc91's 92 92 and mc101's have eight ports. the two extra ports provide a huge advantage in performance. if you want to be almost competative ask to enter into the mc91 100 cc rear class. you'll still be a slight fuel flow disadvantage but the longer stroke will even things out a bit. or you can run in historic un-scored where you'll have a huge advantage with your engine supposedly but your wt. will drag that down a bit. of course there are some clowns me included that run modified 9 ported motors in that class. totally legal but a bit unfair to the other guys. my mc10 that i blew up was fast enough to run with the mc91's but it lost alot of historics with carb issues mis-adjusted clutches blown chains bad gearing. i still had alot of fun running it regardless of results. point is unless you intend to get into the racing end of things gear tuning is part of the learning process. so bring what ya got. if you need a different number gear tooth find me in the pits i'll lend ya wghat ever i got in the box. jeff, i'm running on less than enough sleep lately and got backwards on the adjustments. probably why i lose a few races here and there too. wish i was drinking too much redds then i'd have an excuse. anyway just trying to see an answer from you and i got it sort of i guess. RE: Avon gearing - Al Postiglione - 07-19-2017 Just an FYI...... I noticed that the N.E. Promoters Cup Series was mentioned regarding "scored classes" and "classes in general". I would like remind everyone that, anyone with karts that fit into the classes being tracked for the series, can at any of the N.E. Series tracks, opt to run as Tier II (non-scored). Also, all classes being scored are scored by the choice of the individual promoters/tracks. i.e. at Avon there are 6 classes being scored. Only 5 of those 6 are also being tracked for the Series. Basically, no one has to be scored...... But every one has to have a good time. Or else! |