I norm do alot of chevelle stuff but i have picked up a 1965 Corvette 327/365 hp car. It has the 8" fined ballancer. It came off the front of the engine. belt kept it in place but it damaged the ballancer. I ordered a new original one but my question is theres no bolt in the crankshaft to hold the ballancer in place, i read there are press fit but also rear others say a solid lifter 365hp is bolted down. I need to know if i should just press the new one on and hope for the best or pull the motor and have the crank drilled. No room in this car to drill it in the car. advice would be great. Thanks
1965 327/365 hp ballancer fell off
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Measure interference then decide
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I have always thought the 1965 340 to 375 HP engines came with the 8" balancer and where bolted on.
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I don't think a 3/8-20 bolt will be strong enough for the balancer.If you are going to drill and tap it yourself.
1- get everything out of your way 2-jack the motor slightly so you're drilling straight 3- get the correct size bolt and 3 piece tap set.Machine shop taps sets come in 3 piece sets.
Thats what i'm thinking. Where can i get a goot tap at. I dont wanna try it with a cheap ace hardware tap and chance it breaking in the crank.
If it was built with no bolt to hold it on a 3/8-24 has got to be beter then nothing. Pluse i can use a ballancer installer to press it on then :thumbsup:
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65s didn't have balancer bolts (at least on Chevelle applications, Corvettes might have been different but I don't think so). However, look at the nose of the crank, it might already be drilled and tapped. The snout on my 65 L79 was drilled and tapped even though it didn't have a balancer bolt (I've added one though).
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Corvette, Shmorvette. If it is mine, and it spins higher than 5000 rpm, I am pulling it and tapping it to a 9/16-24UFT
Its not threaded. Its a tappered hole only about 1/4 inch in.
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It's not that difficult. A 90 degree angle head drill would really help. You can probably pick one up at a pawn shop.
Send me your address, and I will mail you a 3/8 NF HSS tap. I probably have a drawer full of them.
You will owe me a favor.
Did you check the keyway in the crank? Last one we had the came off (at 7 grand) screwed up the keyway in the crank also. Mind you that balancer we had to pick up off the street. It was also junk after that. The balancer that is.
Doesn't always screw up the keyway in the crank but it can.
Doesn't always screw up the keyway in the crank but it can.
I would agree with this having done my share of 100% stock-appearing builds. Have never seen a S/J crank with a bolt installed from the factory.
Having said that, this is one of the biggest issues we have with customers doing these type builds, they do not want the crank drilled and tapped but they do "want" a warranty on the build.
The only way we stand behind this area, without the bolt incorporated, is "double" key the cranks, simlilar to way it's done with blower hubs. I've done many with this method and never lost a single one. Very important here though, you need an excellent press fit going in or you will pay later!
(Add) Personally I would rather lose a couple points at the "judged" show, install the damper bolt/washer, and sleep a little better!
Thanks, Gary in N.Y.
P.S. My own preference is drill & tap, and do the correct size, 7/16"-20. Years ago the original "DZ's" had this very issue, was actually very common, and these WERE factory drilled! If you "spun" the damper on one of these, you didn't bother checking anything, you just got a new crank AND damper beforehand.
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Mine (L79) ran around for nearly fourty years and uncounted high RPM blasts without a bolt to the tune of nearly 150,000 miles and never had a problem. However, the last time I did any major work on the engine I put a bolt in which was especially easy since the crank snout was already drilled and tapped. Original crank, original 8-inch balancer. Sometimes it works, sometimes it doesn't but the bolt is good insurance. If anyone ever even notices the bolt they assume it's been there since 1965.
Thanks everyone for the advice. I drilled and tapped the crank. I was pretty easy to drill. keyway looked ok, put a new ballancer on and it seams good.
I'll say this, when i removed the water pump pulley there was a 1/8 spacer behind the pulley. Didn't much about it till i put it back together just like i removed it and the water pump pulley was out to far. My guess is whoever put the engine together never had the ballancer on all the way. cause now with the new ballancer pressed on i dont need that shim for the water pump. prob why the ballancer came off.
I'll say this, when i removed the water pump pulley there was a 1/8 spacer behind the pulley. Didn't much about it till i put it back together just like i removed it and the water pump pulley was out to far. My guess is whoever put the engine together never had the ballancer on all the way. cause now with the new ballancer pressed on i dont need that shim for the water pump. prob why the ballancer came off.
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I don't want to think about how the crank gear of the timing set has worn; or for that matter, how the crank snout has worn.
Hi Rich, that 1/8" spacer you had in there suggests it was an original early Vette unit. They all had that included when they used the front "motor-plate" style mounting system on the water pumps.
It was the thickness of the plate itself, 1/8". It was to guarantee pulley alignment.
It has little effect on the balancer "staying or going".
Thanks, Gary in N.Y.
P.S. Can't tell you years ago how many calls I would get asking why the belt alignment was off?? Most "conventional" rebuilders never knew that ring was in there for the Vette's!! It would get "lost" during the disassembly or crank replacement.
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