Author Topic: Oem Transmission and Big Bore Engines (Read 4847 times)

Anthony0327 · « **on:** October 14, 2014, 09:52:05 PM »

Just want know from people who have big bores how their stock transmissions are holding up and which trans they have. i know LED offers 1st through 3rd gear. Will I be fine with a stock tranny on 300-350cc or should I just spend the money and get the gears. I have an almost brand new 86 trans and I also have an 88 trans. Anyone with experience that has an opinion would be greatly appreciated on this topic. Thanks.

Piney0 · « **Reply #1 on:** October 14, 2014, 10:18:07 PM »

I don't have a big bore yet, so I can't answer the longevity part - but I'm curious to hear opinions on this. I also have a spare low hours '86 transmission. I do know 1'st gear through 4'th gear have the same ratios between the year ranges, and 5'th and 6'th were the ones to change.

PS, where in South jersey are you? I'm in Ocean County.

Anthony0327 · « **Reply #2 on:** October 14, 2014, 10:24:29 PM »

That helps. Didn't know that. I'd like to use the newest one I have. I live in gloucester county

Tbone07 · « **Reply #3 on:** October 14, 2014, 10:36:39 PM »

This is a common question. I feel confident that a solid set of OEM transmission gears could handle a 350cc engine. Maybe have them cryo-treated and magnafluxed for insurance. There are a lot of guys running OEM gears with engines even past 350CC and 65+ HP. If it was my high-dollar build, I would opt for some type of aftermarket gears (like the LED, with the new lower price), or find excellent condition OEM gears

I guess it just comes down to how much are you willing to spend for "insurance"?

Pumashine · « **Reply #4 on:** October 14, 2014, 11:13:48 PM »

Quote from: Tbone07;44561

I guess it just comes down to how much are you willing to spend for "insurance"?

There is a member here who used to race his 467 puma every weekend. He put over 200 hours (4 years)on the stock tranny before it needed to get a new 2nd gear and renikasil the bore. Best value is to get them cryo-treated and have second back cut if you are racing.

Anthony0327 · « **Reply #5 on:** October 15, 2014, 12:05:28 AM »

Thanks for the info Puma and Tbone. You have helped me with questions in the past and always give great advise. I have an almost brand new 86 transmission and an excellent condition 88-89 transmission. I have spent a lot of money already so a few extra bucks won't kill me. My bottom end will be completely brand new except for the tranny. Everything else including cases are right out of the package. Where can I get the trans treated? I know of someone but I really don't care for them or trust them from what others have posted in the past about them. Plus I don't want to ship my trans across the country.

Tbone07 · « **Reply #6 on:** October 15, 2014, 08:44:48 AM »

I think Neil [MENTION=335]C-Leigh Racing[/MENTION] knows where to get them done

F-Red · « **Reply #7 on:** October 15, 2014, 12:28:40 PM »

Running a ESR 330 with stock tranny. Knock on wood :lol: good to go!!!

kb250r · « **Reply #8 on:** October 15, 2014, 10:53:40 PM »

Imo if you gonna pay to treat them just go led gears,it means nothing but I had a set of magna fluxed,cryo and heat treated gears and spit second gear right out the case out onto the ground in a matter of a few hole shots.. I now have been running the LED gears and have had great luck