Dump the gear and go timing chain?

[Alky V6]

I'm not sure if it's my assembly techniques, lubrication mods or what, but I've been using the same Milodon geardrive unit since 2005 in two different motors. The latest engine has been together since 2008. Lots of testing. Lots of passes.
My setup makes zero noise.
I do take special pains in fitting the geardrive mounting plate to eliminate any clearance movement to the mounting bolts. Kind a like mounting the plate on tight fitting alignment dowels. I also feed a spray of pressurized oil to the idler gear bearing. Red loctite is all my setup has needed.
Do away with the flat roller type idler bearing and use the ball bearing style with it's simpler mounting shaft. No little screws to come loose with that style. Just one honkin shaft with a large thread, loctited and torqued to the mounting plate.
I don't know how some of you are ending up with a noisy setup. I dare anyone to even use a stethoscope and try to tell if it's any noisier than a chain in my engine.

 

[turbobitt]

My gear drive is a single bolt style and makes little to no noise. No special oiling modifications made and believe that its not needed. My idler gear was secured using loctite 680. I also street drive this very often.

BTW - 680(Green) retaining compound is more resilient to motor oil than thread locker loctite 271(Red) and is a better choice to permanently lock fasteners in this type of environment.

Allan G.

 

[WIKEDV6]

I agree a chain would be fine in this situation.



As far as 500# seat pressures, I do not know of any turbo Buick pressures that high even in the 7 sec. builds. :biggrin:

Well Nick I know some one on this board running 450 on the seat but I don't want to disclose his name. I understand that he wants to go even higher. If he wants to chime in that's fine with me. I know Odell Cantrell runs 400 and change on his car along with few other well known fast guys. Thus I made the comment close to 500.

Prasad

 

[Alky V6]

My gear drive is a single bolt style and makes little to no noise. No special oiling modifications made and believe that its not needed. My idler gear was secured using loctite 680. I also street drive this very often.

BTW - 680(Green) retaining compound is more resilient to motor oil than thread locker loctite 271(Red) and is a better choice to permanently lock fasteners in this type of environment.

Allan G.

I've always used a 271 equivalent on the assembly. In multiple teardowns over the years, it has always been found to hold. In fact, I'd be a little nervous if it held any better than it does. Idler shaft always releases with a lot of needed torque (scary) and a nice SNAP! Just make sure the thread surfaces are clean and dry before applying.

 

[BlownV6]

Im sure there will be people come in here going "I have a gear drive and its awesome!" Found the idler gear for the gear drive intact with the bolts in the oil pan.

There ya go!! Most likely an assembly problem with lack of attention to detail in this area. Just my opinion!! Mike

 

[BlownV6]

.
As far as 500# seat pressures, I do not know of any turbo Buick pressures that high even in the 7 sec. builds. :biggrin:

Im over 450# , soon to be 500# with my new heads. I know of several others at the top of the TSO heap that are in this same area!! Just an FYI
Mike

 

[Squid4life]

I do take special pains in fitting the geardrive mounting plate to eliminate any clearance movement to the mounting bolts. Kind a like mounting the plate on tight fitting alignment dowels.



Do away with the flat roller type idler bearing and use the ball bearing style with it's simpler mounting shaft. No little screws to come loose with that style. Just one honkin shaft with a large thread, loctited and torqued to the mounting plate.

Donnie, (or anyone else for that matter) how hard is it mounting the idler plate to the face of the block. I am about to start mocking stuff up and with all this info about issues with gear drive mounting, alignment, carnage, etc, I am curious how tough a job it is to drill, tap, etc the front plate for the gear drive. I have a gear drive with all mounting bolts, but this thread is making me nervous about it. :biggrin:

Also, are you talking about two different types of idler mounts or bearing types, or are you talking about a mod you do? I have two different idler brackets from two diff gear drive setups. One has a single bolt on the back (IIRC) and the other has 3... I may post some pics up if this is not clear. Just curious if this is what you are referring to, or if you re-engineered your own version.

 

[Alky V6]

Squid4life, go ahead and post the pics of your idler gears and shafts. I'll pick it out for you.
I didn't re-engineer the idler shaft with my setup.
What I did with the mounting plate was rework a few of the mounting holes so that when mounted on the block there was no free clearance for the plate to move around if the bolts ever managed to work loose. The positioning of the plate also had to take into account the proper running clearances for the gearset. It's not an easy process. It requires being able to weld up hole(s) in the plate and precisely machining new ones. Once it's done, the plate can be removed and replaced on the same block without having to re-set the gearset running clearances. The fit of the bolts will properly and precisely position the plate to give the proper running clearances.

 

[jlat]

hello peoples: HIJACK!!! I see Arizona GN has been speaking on this subject. How about posting something about your new SLIC I heard that your cumming up with. I never called but I did E-mail and putting something on this site would be profitable for you in the future. A taste of it with pics would be nice.
IBBY

 

[WIKEDV6]

Im sure there will be people come in here going "I have a gear drive and its awesome!" and like I said, there are a few good units out there but most people are recycling the old stuff thats out there (I dont think any big company currently makes a V6 gear drive anymore) and you're just asking for it. Id rather replace a chain once a season than deal with the carnage of a broken gear drive. We had one come loose mid pass and took out two turbos, a set of heads, a piston and the gear drive itself.

Valvetrain stopped moving, piston hit valve, knocked the head off the valve, knocked the seat loose from the head, beat the crap out of the combustion chamber, spit pieces back into the intake which went out a cylinder on the other side and put pieces into both turbos.

Found the idler gear for the gear drive intact with the bolts in the oil pan.

Awesome

Hey Jay, I have a great deal of respect for you and I know you have been playing around with “big dog” stuff more than most people I know.
I too am confused with the Gear Drive vs the Chain. What makes me think that the gear drive is better and stronger is that; Buick Race Team/engineers spend a lot of research and tons of money on these motors to run hours at a time spinning motor constantly 6-8K RPM or more. ( I really don’t know how long the race is but I know its hrs at a time!)

So my questions is; if the gear drive setup is good enough to take all that abuse and the Buick race team ran them with confidence, why would it cost problems under less stress? At least at the power level us small guys looking to make.

P.S the motor 2GNS4ME has on hand was initially assembled and setup with Gear Drive from Mr. Ruggles him self!!. The motor just went through a freshening up right now.

When I ordered my cam from a shop from FL, I was told that Gary Harmon lost his motor due to broken chain.... I think there is guy here on the board with a Stage II in a TTA...some where I read that he bought his motor with a broken chain.

This is getting crazy as to which way to go!

TIA
Prasad:frown:

 

[geno]

The harmonics that people talk about with our Buick v6 motors is from the cam having only 12 lobes instead of 16 like a v8 With 16 lobes you have better opposing forces as one roller goes over the top another is coming up the ramp sooner to counter it and has less duration between 2 lifter going over the top My motor has over 300# spring pressure on the seat witch is nothing compared to others:biggrin: When i roll the motor over with no plugs the crank turns backward or forwards by its self and wont stop turning until a lifter is not coming down off the top of a lobe. So the chain or gear drives see,s alot of shock from this pulsing action.The chain goes slack when a lifter goes over the top of a lobe and then tight before it goes over the top to open the next valve.I believe thats why belts are the best because they can absorb the shock loads better and is damped some what.
This shock load can loosen the bolts or kill the needle bearings on a gear drive because it is so rigid and does not absorb the shock .This is just my thought on this and im just going to change my chain ever so often.If i had the money i would have one of those Danny Bee belt drive setups Mike is selling on my car

 

[JayC]

Belt drive is where its at. I didnt even bring that up because I didnt know you could still get them. Last I heard someone bought up all the old Danny B units and was selling them off but that was quite a few years ago.

 

[geno]

Belt drive is where its at. I didnt even bring that up because I didnt know you could still get them. Last I heard someone bought up all the old Danny B units and was selling them off but that was quite a few years ago.

Also this same harmonics is why it so important to have the right clamping force on the cam gear. Some people have had problems and think its the key holding the gear from spinning and its the clamping force of the bolt holding the gear on that stops it from spinning.The stackup with the gear has to be right so the cam snout is below the cam gear and doesnt bottom out the washer on the snout before it has full clamping force to the gear . Plus a good thick steel washer and ARP bolt is needed.


http://www.turbobuick.com/forums/stage-ii-tech/226630-danny-bee-belt-drives-anyone-intrested.html

Gene Fleury
DLS Fan Club LOL

 

[GARY HARVEY]

Safety wire on everything you can, if you can't figure out some way you can use safety wire,
get some help.

Use Everclear to flush threaded areas before Loctite.. (then have a shooter ;>)

If you decide to use a chain, Roll Master.
Concerned about stretching, 300Below.


I've had good luck with both systems.
Gear Drive with high seat pressures
and chain for 275 lbs. or less.
If it's a street car, why more than 250 lbs?
(It's like carrying a 5 lb. hammer to kill flies)

 

[2GNS4ME]

Okay guys going to try the gear drive setup in. A reputable shop Put it in but I'm going to take it to another shop to have the check the mildon gear drive setup. Anyone have the clearance info for the gears?

 

[WIKEDV6]

Guys, here is some good information from my buddy who has a pretty fast stage II, stage II headed car. Middle of last season he broke the timing chain and he went and replaced it with a new known good brand timing chain. He has the motor at the machine shop to look things over/freshen it up. Well, the machinist found that the timing chain is loose already with only seven passes. This was a brand new timing chain!
I guess I am sticking with Gear Drive for sure!
Prasad

 

[Mike E]

I'm putting the gear drive in mine also. I took both a gear drive and timing chain setup to my engine guy and with no hesitation he picked the gear drive.

Everybody says the geardrives induce harmonics into the valve train. I'll argue that a timing chain does also, but that's a different thread. If a gear drive does put more harmonics into the valvetrain the downside is wear on tear to valve springs and lifters. So worst case is you break a valve spring and bend a valve or prematurely wear a lifter. Worst case with a timing chain is you break a chain and bend half the valves and ruin half the pistons. I'll take my chances with the gear drive. I do think the setup of the geardrive, how it's fastened, gear clearances, etc. are all very very important. A gear drive should not be a bolt on and go deal for your average home assembled engine. You should also be checking valve lash somewhat regularly to see signs of a failing lifter.

 

[WIKEDV6]

I'm putting the gear drive in mine also. I took both a gear drive and timing chain setup to my engine guy and with no hesitation he picked the gear drive.

Everybody says the geardrives induce harmonics into the valve train. I'll argue that a timing chain does also, but that's a different thread. If a gear drive does put more harmonics into the valvetrain the downside is wear on tear to valve springs and lifters. So worst case is you break a valve spring and bend a valve or prematurely wear a lifter. Worst case with a timing chain is you break a chain and bend half the valves and ruin half the pistons. I'll take my chances with the gear drive. I do think the setup of the geardrive, how it's fastened, gear clearances, etc. are all very very important. A gear drive should not be a bolt on and go deal for your average home assembled engine. You should also be checking valve lash somewhat regularly to see signs of a failing lifter.

I agree 100% Mike, Also a good friend of mine went with the gear drive and has gone 9.80's so far. He said unlike other motors, when you setup a gear drive properly in a Buick, it will not make any sound. His motor is as quite or quitter with the Gear drives vs. the chain.
Prasad

 

[Alky V6]

People are finally learning.
I've been using the same geardrive set since around 2005 in 2 different builds. No noise and the lifters and valve springs have been lasting fantastically. A little over a year ago, maybe two, I changed out the valve springs after running the same set for over 3 years. Pressures were still acceptable. I simply changed them out as a preventive maintenance thing based on run time.
Some people may be seeing premature fatigue of the valvetrain and simply blaming it on the geardrive. There are a lot of other factors in a valvetrain that will cause premature fatigue of components. Especially when you get into high rpm and high spring pressures.
The only thing I've experienced using the geardrive has been complete and utter,... peace of mind.

 

[Mike E]

One thing I've noticed as I see various gear drives come up for sale. There are the obvious two types of idlers. One with three bolts and one with a single large bolt in the middle of the idler.

There are also a couple of different backplate mounting styles. The gear drive I have has the three bolt idler and 1/4-28 socket head cap screws that go into the galley plugs (behind cam gear), and 1/4-20 button heads that go into the block by the crank. My block is an old round track piece and the holes in the block and galley plugs were tapped 5/16-18. I've seen some backplates that appear to be held down with 5/16" flat head cap screws in the galley plug and 5/16" socket heads in the block. I'll be modifying my backplate to use the 5/16" hardware, but are those other plates actually useing flat heads behind the cam gear. Or are they using button heads? It seems like a flat head would limit the movement to align the idler gear.