Crank gear & BSD info

[06Speed6]

I decided to not send my crank to John.

I talked to my engine machine shop guy and he told me he has been cutting them off of old Chevys and Caterpillar engines for years with no effect on engine balance or durability. The reason is that the ring gear weighs the same amount all the way around and cutting it off has zero effect on the balance of the crank. He also stated that even if it did somehow change the balance of the crank, the equipment that balances the crank only has pickups for either end of the crank and that the middle of the crank is typically always somewhat out of balance, but it is compensated for at either end of the crank.

He also added, for those that don't already know, that the balance shaft does not actually balance anything. The balance shaft cancels vibrations from any imbalance in the rotating assembly, but it doesnt actually balance the assembly and removing it doesnt change the durability or longevity of any of the engines parts.

Beyond that he also told me that the reason OEMs use steel crankshafts in alumnium blocks is because the blocks twist and move and the steel crank can twist with the block and still be reliable. He suggested that some of the twisting could be causing the actual BSD assembly to bind and fail, but he said that the twisting would not cause the gear to contact a rod and break the rod unless the actual ring gear were to come off.

I put a fair amount of confidence in my machinist since he has been building race engines for longer than I have been alive, he suggested that if oiling and knock were not a problem to look at heat and block flex. He is also assuming that he OEM parts can take what we are throwing at them.

[MarkyMark]

Originally Posted by 06Speed6 I decided to not send my crank to John. I talked to my engine machine shop guy and he told me he has been cutting them off of old Chevys and Caterpillar engines for years with no effect on engine balance or durability. The reason is that the ring gear weighs the same amount all the way around and cutting it off has zero effect on the balance of the crank. He also stated that even if it did somehow change the balance of the crank, the equipment that balances the crank only has pickups for either end of the crank and that the middle of the crank is typically always somewhat out of balance, but it is compensated for at either end of the crank. He also added, for those that don't already know, that the balance shaft does not actually balance anything. The balance shaft cancels vibrations from any imbalance in the rotating assembly, but it doesnt actually balance the assembly and removing it doesnt change the durability or longevity of any of the engines parts. Beyond that he also told me that the reason OEMs use steel crankshafts in alumnium blocks is because the blocks twist and move and the steel crank can twist with the block and still be reliable. He suggested that some of the twisting could be causing the actual BSD assembly to bind and fail, but he said that the twisting would not cause the gear to contact a rod and break the rod unless the actual ring gear were to come off. I put a fair amount of confidence in my machinist since he has been building race engines for longer than I have been alive, he suggested that if oiling and knock were not a problem to look at heat and block flex. He is also assuming that he OEM parts can take what we are throwing at them.

Now I'm even more confident in leaving it on the crank after my machinist whos been doing it for 16 years told me its not worth the hassle or the labor involved.

great post.

[Deadman]

W00T! marks gay and built a fake motor

[MarkyMark]

Originally Posted by Deadman W00T! marks gay and built a fake motor

lol.

[bioevolve]

Now 06Speed6's post makes a whole lotta sense! Thanks!

[whoosh@Realtune]

Originally Posted by 06Speed6 I decided to not send my crank to John. I talked to my engine machine shop guy and he told me he has been cutting them off of old Chevys and Caterpillar engines for years with no effect on engine balance or durability. The reason is that the ring gear weighs the same amount all the way around and cutting it off has zero effect on the balance of the crank. He also stated that even if it did somehow change the balance of the crank, the equipment that balances the crank only has pickups for either end of the crank and that the middle of the crank is typically always somewhat out of balance, but it is compensated for at either end of the crank. He also added, for those that don't already know, that the balance shaft does not actually balance anything. The balance shaft cancels vibrations from any imbalance in the rotating assembly, but it doesnt actually balance the assembly and removing it doesnt change the durability or longevity of any of the engines parts. Beyond that he also told me that the reason OEMs use steel crankshafts in alumnium blocks is because the blocks twist and move and the steel crank can twist with the block and still be reliable. He suggested that some of the twisting could be causing the actual BSD assembly to bind and fail, but he said that the twisting would not cause the gear to contact a rod and break the rod unless the actual ring gear were to come off. I put a fair amount of confidence in my machinist since he has been building race engines for longer than I have been alive, he suggested that if oiling and knock were not a problem to look at heat and block flex. He is also assuming that he OEM parts can take what we are throwing at them.

you go man!
good work

[Fobio]

how does having more solid mounts affect engine flex? do they decrease it because they help limit movement? or increase it because the engine itself absorbs more movement?

[Grim]

06speed really knows his shit,and im glad i live so close to him!!!!

[06Speed6]

Originally Posted by Fobio how does having more solid mounts affect engine flex? do they decrease it because they help limit movement? or increase it because the engine itself absorbs more movement?

A motor mount doesnt do anything for the engines internal parts. They simply keep the engine from moving so much in the engine bay.

[Crossbow]

Thanks a ton for the info! This helps alot!

[RUMBLEFISH]

Thats if for me also. As soon as I get my PT kit off comes the ring gear. If it blows up Im gonna sue the internet.

[ATE BALLER]

Yeah, I might go ahead and do it. Your reasoning makes sence. So just a dremel w/ a cutting tip? How is it secured to the crank?

[fbpem1]

Originally Posted by ATE BALLER Yeah, I might go ahead and do it. Your reasoning makes sence. So just a dremel w/ a cutting tip? How is it secured to the crank?

yes a dremel or a cut off wheel very carefully does the trick only took about 10 minutes to do since you have to go slow in the car, then a saft tappy tappy from a plastic deadblow hammer on the gear itself and it goes PING rotate PING done, it falls right out.

[bioevolve]

One question:
Does the oil from the pick up tube go straight to the oil filter first then sent out to the oiling spots throught the motor? TIA!

[06Speed6]

Originally Posted by bioevolve One question: Does the oil from the pick up tube go straight to the oil filter first then sent out to the oiling spots throught the motor? TIA!

This has nothing to bo with the topic, but it goes from the pickup to the pump to the filter to the engine. It is that way for every engine made since the 1940s.

[MS6_Auburn_Fan]

Ok so you have decided to cut off the ring gear that drives the BS assembly? What was John gonna do differently or were you just going to have him do it for you?

Sorry I was confused when I read this yesterday I thought you had decided to leave the ring gear on there. Which one is it?

[superskaterxes]

bsd ftw

[06Speed6]

Im going to take it off with the crank in the car. I have another crank I was going to send John, but it will not provide any useful info that we dont already know.

[ptperformance]

Thanks 06speed for the post I am sure that this cleared alot up for those that were questioning the effects of the ring gear.

Last, I want to mention (talk with your machinist about this as well if you get the chance) the ring gear if left on the crank can throw the oil around in the motor. This could cause some windage or oil vaporing that is not necessary due to how easy removing the ring gear is. I think that only possitives can come from removing the ring gear, nothing negative.

Again, thank you for taking the time to post your findings on this in my section.

[06Speed6]

Yes it would, people dont knife edge cranks for no reason.

[m4tic]

sooo... i am not installing my kit this weekend, i dont have anything to cut the gear off with guess i'll change my oil

[Demi]

Here mine.

[TRU-BOOST]

So i am going to do this. I was against it at first. I thought it was too much trouble just to remove some rotating mass. Now learning that it very may well keep me from blowing my motor.... I'm in !! I have a few questions though.
First, as far as removing the gear, what exactly is being cut to remove it ?
Also DEMI .... If i am looking at this correctly, you didnt remove the gear. Is that correct ? That thing looks way too close to the rod for my liking. I will for sure be removing both pieces. Shit a $20 mod that can save my motor for a few hours of work .... Sounds good to me. I'll pass on the baffle personally. Call me cheap but i dont see it needed.

[fbpem1]

Originally Posted by TRU-BOOST So i am going to do this. I was against it at first. I thought it was too much trouble just to remove some rotating mass. Now learning that it very may well keep me from blowing my motor.... I'm in !! I have a few questions though. First, as far as removing the gear, what exactly is being cut to remove it ? Also DEMI .... If i am looking at this correctly, you didnt remove the gear. Is that correct ? That thing looks way too close to the rod for my liking. I will for sure be removing both pieces. Shit a $20 mod that can save my motor for a few hours of work .... Sounds good to me. I'll pass on the baffle personally. Call me cheap but i dont see it needed.

put a socket on he crank pulley bolt and rotate the motor over so the rod is fascing up and far away from the gear. simple enough.

[ATE BALLER]

I'm still confused to how the gear is actually held to the crankshaft. I'm getting ready to switch out my f2 baffel with the ptp windage tray, and I'm planning on pulling the gear while I'm at it. So you just cut the gear at the cogs? turni it and repeat? I just don't see how it would be held in place. It can't just be magically floating around the crankshaft with no spokes or anything.

[fbpem1]

its held on JUST like a flywheels ring gear, theres no tac welds or anything, when they are installed at the factory they are heated to xxx probably 310 degrees, and it slides right on then instantly cools and thus tightening.

[TRU-BOOST]

Ok sounds easy enough. And in the last hour i have already placed my order. I guess you can call me a liar... I said i wouldnt buy a baffle, but i said WTF. I bought the windage tray/baffle and BSD plug from ptp. I hope it arrives quickly. The rest of my car is nearing completion. It would be great to get this done before the car comes out of hybernation !!

[Demi]

Originally Posted by TRU-BOOST Also DEMI .... If i am looking at this correctly, you didnt remove the gear. Is that correct ? That thing looks way too close to the rod for my liking. I will for sure be removing both pieces.

Naw I left it in there. Im gonna be swapping in a the PTP windage tray at some point and ill cut that off. What did everyone use to do theirs?

[06Speed6]

I left mine on for the time being.

[ptperformance]

Originally Posted by TRU-BOOST Ok sounds easy enough. And in the last hour i have already placed my order. I guess you can call me a liar... I said i wouldnt buy a baffle, but i said WTF. I bought the windage tray/baffle and BSD plug from ptp. I hope it arrives quickly. The rest of my car is nearing completion. It would be great to get this done before the car comes out of hybernation !!

Thanks, you should have your parts in hand middle of this coming week.

Originally Posted by Demi Naw I left it in there. Im gonna be swapping in a the PTP windage tray at some point and ill cut that off. What did everyone use to do theirs?

What we have done it take a cut off wheel and cut one side close to the crank but not to close, rotate it around and then cut the other side off, again close but not to close. Brass hammer with a small chisel and bingo bango the gear cracks in 1/2 and falls down onto the ground. Its very easy to do in the car you just have to take your time. One tip I will give you, get 4 cans of brake cleaner. This way you can clean the oil from dripping down on you while you cut the gear off and then clean up after wards to get all the junk out from in side the motor. I would remove the oil pump pick up tube as well and to be super safe, tap the feed hole up on the pump. This makes sure that 100% of the debris stays out of the pump.

Originally Posted by 06Speed6 I left mine on for the time being.

Time being... being the key word.

[TRU-BOOST]

Thanks man. I look forward to the install. Dremel with 2" reinforced metal cutting disks FTW !!

[fbpem1]

the dremel takes fucking forever, i used a 3'' cutoff wheel on my die grinder air tool and then...used the dremel for the last little bit.

[TRU-BOOST]

Somehow i have every other air tool on the planet, but not a grinder. I figures the dremel will take longer, but oh well. Also i got the big 2" disks. Not the little 15/16" or 1 1/4" in things. That should help a little.... I hope. Otherwise my patience will be tested !

[fbpem1]

honestly i get most of my die grinders from harbor frieght they are like 15 bucks apice i have 5 of them each with a different attachemtn on them so i don't have to go back and switch them back in forth i just grab the other tool

[gsrtype1]

great thread

[ptperformance]

Thanks for keeping it alive guys, I agree great thread.

[phillyb]

i am somewhat afraid of cutting the gear. i guess a shop vac would allay some of my worries

[TRU-BOOST]

As long as you are careful it will be fine. Just be sure to position your cutting tool so that the sparks and shavings are flying downward, not up in the cylinders. Then lots of brake clean !

[slo4now]

I thought about removing the ring gear for awhile when i was underneath the car and
said the hell with it, it's staying on for now.
All the tiny shavings made me think twice.

[TRU-BOOST]

Not removing it is gonna make that gear sling oil all over the place. That could cause excess vapor and oil foaming. Even with a baffle i am pulling it off. It sits too close to that rod IMO anyways !