Which weight balancer is correct for a '81 302. I've heard 28 oz. up to '80 and 50 oz. '81 & up. Have also heard 28 for up to '81 and 50 '82 and up. anyone know for sure and if the incorrect balancer is used will it be really obvious, as in vibration?
Theoretically, you should need a 50 oz as the dividing line is 1981, 80 down is supposed to be 28 oz. BUT, you are right on that transition year and with Ford it is hard to tell what they did sometimes. Don There might be some info in this link to help you out. http://www.rowand.net/Shop/Tech/FordFlywheeslAndFlexplates.htm
I don't think so. I have a few flexplates in the shop from pre 81 and post 81 and the weights on the back of the later ones is much larger. I could be wrong, but I have always kept the early with earlly and late with late. My 331 stroker kit came with a 28 oz imbalance and I was able to use my early flywheel with it instead of the later 5.0 one I have. My understanding has always been that you have to match both the damper and flexplate/flywheel to the year of the engine. Don
Flywheel/flexplate and dampner in an OEM application must match the manufacturers specs. In a built or aftermarket engine it can vary. It can be externally balanced, or it can be internally or neutral balanced. Some stroker crank kits have require both internal on one end and external on the other, so you must be careful. The stock SBF for example can of course be external with either 28oz per/inch or 50 oz per/inch inbalance. Both ends must match in these stock factory applications. Yes, you should notice the inbalance while the engine is running, exactly where in the RPM range it could vary. Yes, the engine could eventually self destruct in a somewhat violent fashion. Of course you can't return a installed dampner, so you need to make sure you purchase the correct one before installing, good luck, TR
I know that I match the balencer and flywheel. Have ran 85 bal / flywheel on a 68 289 for 40,000 miles. No problems. If you don't get it right you'll know . Violent shaking gives it away.
To the O/P, some company's such as Professional Products offer dampers for the SBF with removable weights. This simplify's thier part number system, as well as make things easy for the end user. Bolt on or off the weight you need for your current balance factor, TR
There's also 3-Bolt & 4-Bolt. I've been down this road. I forgot which oz. is which though. That's why Chevy has dominated this hobby.
Yes, there is also a 3 and 4 bolt balancer. The later or 50 oz/per inch balancer is the 4 bolt. Some of the aftermarket balancers have dual bolt patterns again to make them universal depending on the balance factor. If I remember correctly, the mounting flange diameter is also slightly diffrent. A spacer is available for that for just a few dollars, if you have a lathe you can make your own, TR
Guy's sorry to say, balanced hormones, or hormonic balances, generally are only weeks 1 thru 3, during week 4 its best just to leave town, TR M.D.
A 28oz (left), and a 50oz (right). The old 3 bolt balancer is 28oz. In 1982 a 302 could have either a 28oz, or 50oz balance. Note on the 50oz balancer how he "rubber" is smaller in diameter than the 28oz.
I would suggest getting this in case you have any further questions about your sbf http://www.amazon.com/Rebuild-Small...4898/ref=sr_1_2?ie=UTF8&qid=1326301992&sr=8-2 It's a good book with a good amount of info. It has all of the answers to your imbalance issues and how to identify your casting numbers to be sure of what you have. Worth my 20 bucks. If I had it with me I'd be able to easily answer your question
According to Ford Racing FAQ...http://www.fordracingparts.com/faq/faq.asp "1968-80 302 engines were built with a 28-ounce imbalance factor. 1981-2001 302 engines were built with a 50-ounce imbalance factor. 1969-97 351W engines were built with a 28-ounce imbalance factor. 1970-74 351C engines were built with a 28-ounce imbalance factor. Note: Severe engine damage will result if you use the wrong flywheel or damper on your engine. " However, we all know that our beloved Ford used up previous years inventory. I had a 1964 Falcon Sprint, 4 speed car that was "badged" as a 260, that actually had a 221 cu in. engine installed from the factory. I'm not sure, but believe that the 28 oz engines had a 2 piece rear main seal, while the 50 oz engines had the one piece. BOutlaw
I have balanced engines for years and depending on what he is doing "stock or after market" stock up to 1980 should be 28 oz and use 28 oz flywheel all so. After market depends on bobweights spin it up and see what it needs. Just my 2cnt's worth
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