New Bearings etc.

[John Scott]

As I suspected it was time for new main bearings. The #1 was showing quite a bit of wear. Rods looked amazingly good with little if any new evidence of predetonation. I'm going to replace them anyway since I'm "into it" I asked around for bearing advice (thanks everyone!) and most seem to recommend the Clevities. I've had good success with them too, but decided to try Federal Mogul's high end line made for racing applications. They cost more, but I'd like to see if they wear any better. Still cheaper than a new engine.

I'm having serious concerns about the belt tension issue and know the 12 rib design will alleviate some of the stress on the front main. This will entail refab.ing brackets and another big deposit in ATI's bank account! Another plus for turbocharging, Scottie!

So, the transmission takes a back seat while I wait for the UPS man, again.

Did a trial fit of a big 3 row ATI intercooler. Looks pretty tight. Need to get my trans. cooler out of the road before I can make any determination. This would be cool because the intercooler is for sale at a good price. A friend claims it's only good for 600 hp or so. Too little for my his 800 hp twin turbo road racer Turbonetics Mustang! See! There's some competition out there!

JS

 

[This message has been edited by John Scott (edited June 17, 2000).]

[Guest RON JONES]

John do yourself a favor and have your crank maged while you have it out.

[John Scott]

Thanks for the tip, Ron. I'm doing the no pull-under-the car- bearing change. Advantage(?) of having a V6. I'm figuring on doing a new engine from square one in the future so I don't have the down time w/o my car. ( Additions to the project are going to be pretty slow around here. New baby girl, ANY day!) This will include all the extras I was hoping to put in this one. 4 bolt mains, better rods, heads, etc. I look in my engine a little more frequently than the average fanatic. Since all this has been experimental, I felt the check-ups would be a good idea. By the time a bearing spins out, its too late. The bearing change is to get me through to the next build. The crank that is in there now was prepped pretty well. Indexed, crossdrilled, balanced, and I would think maged. Block was align honed. I was getting a little flex from the 2 bolt mains, but have taken the Max rpm down a little. Along with Magnufluxing, what is your opinion of Nitriding? A waste of $$? A few of the REALLY high boost Syclones are adding this to there build lists.

JS

[Guest RON JONES]

I would have the crank maged first.Then if its fine,If the nitriding isn,t to expensive I would go for it,it couldn,t hurt.Even if you had the crank maged when you first did the motor,with that #1 bearing showing wear because of the stress of the supercharger drive,I would have it maged again.It sounds like the crank is under alot of stress if it is showing more wear on the front bearing than the rest of them.Its good insurance that everything is fine.Ron

 

 

 

[This message has been edited by RON JONES (edited June 18, 2000).]

[Guest Fast Frog]

JS:

 

I've been following this post. Let us know when the new arrival arrives!! Baby girl!! Not engine parts!! If I'm lucky, one of these days I'll become a Granpa. The kids will have to get "busy" first.

[Guest Locutus]

I know how he feels, I got a baby girl on the way too. Though I have 3 1/2 months to wait still. We just found out the sex last week and I am so excited. Congragulations John and good luck.

 

Mike

[Guest RON JONES]

I have a 5 year old girl(Lauren)and a 3 year old boy(RJ),so I can relate to what your going to be going through.It seems like my Son was born yesterday.I would also like to hear about the birth of your daughter.I hope everything goes good for you and your wife and wish you luck.Both my kids were born after 20+ hours of labor,exhausting.My wife was tired to.HE HE HE.....John is this your first?

 

[This message has been edited by RON JONES (edited June 18, 2000).]

[John Scott]

Number 2. After 10+ years of marriage and 2 weeks after buying my Z, bango ..."dear I feel funny this morning!". Four years later, here comes the next. My son really loves "the orange car". New how to say carburetor, supercharger, radiator etc. before he was 3! Has his own step stool next to the fender. Gave him lots of play tools. Never touched them. Always went for the real ones. Used to sleep with a holley fuel regulator under his pillow! By far the most important and amazing part of my life.

Oh yeah, been hammering away on the underside for the slave clearance. Seems so crude...yet satisfying!

JS

JS

[pparaska]

John, umm, having a 7 and 4 year old, I've been through all the kiddy movies too. "(blank),...yet satisfying". That's from Lion King - I bet.

 

Happy Father's Day all.

 

P.S. John, if that bearing is showing wear, I agree with Ron that you ought to mag the crank. Sounds like the thing is under some severe bending. That's a fatigue testing machine you have going there BTW. Is that a toothed belt setup?

[pparaska]

John, I was wondering if you had other options as well. Here are my ideas (without knowing what your setup really looks like):

 

1) Larger diameter pulleys on the crank and blower? This would help increase the belt surface area. Of course, you'd want to keep the same diameter ratio as you have if you like it. Maybe there's not enough room for this.

 

2) Larger wrap angle on the pulley that is slipping? I'd imagine there might be an idler pulley, or maybe the blower is adjustable on it's mounts for belt tension. Again, just an idea, but if you could configure it for more belt contact angle, you'd increase the surface are of contact.

 

3) Custom Toothed belt setup (like the Roots blower guys run)? Bucks, I'm sure. Maybe something halfway affordable from another application might fit?

 

Just a few brain farts, hope they helped

 

[This message has been edited by pparaska (edited June 19, 2000).]

[John Scott]

Thanks Pete. You have either good intuition or been reading up on blowers! All good recomendations. I've experimented, but perhaps not exhausted the belt wrap issue. I've moved, redrilled the idler pulley to 5 different locations. Toothed belts aren't recommended for the street, at least not the kind of driving I'd like to do. Harder on the motor, wear faster, need precision alignment with no deflection. Also a bigger case is recommended like the ATI P1200. Need a bypass valve(got that) or they'll bend something important when you shut down @ 7000 rpm., and yes they're expensive. Your pulley size idea has great merit. More area around the pulley is good. Same reason tall tires give better straight line traction. Paxton's older set up uses this to advantage (big driven pulley) with a higher step up ratio (4.44:1) in the blower's transmission. They just couldn't handle high RPMs (39,000)and thus only give small boost #s. I have minimal clearance under my drive pulley already so I'm stuck with the size I have. ATI has the largest engine pulleys out there @ 7.65 in. At least as of '98. They're step up ratio is 3.05:1 but with the larger lower pulley and really strong gearboxes, could handle lots of RPM (60,000) and way higher boost. They were the first to come out with a 12 rib, and have the cogged for the big units as well. Some racers resort to using traction compounds on the belts.

BTW the MONDO Vortech crankshaft support strut is a piddly $500+. OW! My only alternative is a 12 rib, and good case bracing.

JS

 

[This message has been edited by John Scott (edited June 19, 2000).]

[John Scott]

Using an 8 rib with a little pulley isn't a good idea. Its not the blower putting the strain on the bearings as much as my trying to overcome the slippage issue. The car magazine articles on centrif. blower tips warn of the front bearing wear with really tight belts. I'm not breaking any new ground here. What I need is a larger surface area for the pulley. That would be a 12 rib design with 50% more contact area. Most of the cars you see on the street run 5-10 psi. You don't need much more than a pair of v belts to do this. Little pulleys with little surface area loose bunches of grip. And as I've confirmed, overcoming the slippage is hard on the bearings. I don't think the crank is flexing as much as the whole thing is being pulled up and towards the drivers side. Bearings show progressively less wear as you go to the rear. A two foot pry bar pulled so hard it makes me f@%+ can put a lot of preload on the crank. Running the car this way for 4 years adds up I'm sure. I think it is Vortech that makes a slick and really expensive bar that spans the pulleys, centerline to centerline, with additional bearings. Considered only for race applications. The 12 rib is the way to go. I think I'll see way less wear with less tension.

JS

[Guest Anonymous]

John, heres another cheep plug, but I promise you need to have your new bearings coated before you put them in. It will really increase your part life, and reduce friction,, just makes good sence while you have it torn down. Does'nt cost that much, I only charge 30.00 for a whole set. There should be a coating shop somewhere near you. If you do , be sure to burnish the bearings to the tolorance you want before you install them . Tony

P.S. or you could send them this way and I will coat them and send them back for 30 +shipping , which would'nt be much.

------------------

74 260, sbc 350, 700r4, and a few little HP Mods.just gettin started good. www.speedtechcoatings.com

 

[This message has been edited by takman57 (edited June 22, 2000).]

[John Scott]

Federal Mogul says they discontinued the main bearings for the 4.3! If this is the case then they discontinued the whole line of small block Chevys. The mains are the same! Apparently its not cost effective to pull one bearing out of a box and call it a 4.3 set. Weird! I had to order the 350 set. Showed up this week. Nice looking units with a 3/4 oiling groove. Rod bearings are to be shipped this week as well.

I have to relocate my 1/2" return line for the T56 swap and then its ready to go. I've done the "ritual beating", had 28 years of crud fall into my eyes, and hit my hand a few times. Loud obscenities could be heard throughout the neighborhood. @#$%in' piece of @#$%, !@# of a )*&^! "Oh, John's working on the Z again!"

Had a nice long talk with FastFrog. He's convinced me to re-evaluate my blower bracing. Also got me excited about FI again. @#$%! Frog! Its hard enough to concentrate on the transmission and bearings w/o you stirring up my wish list again! Its great to talk to another enthusiast.

JS

 

[This message has been edited by John Scott (edited July 01, 2000).]

[BLKMGK]

Just a quick word of advice - don't use cogs on the street. The deal is this - when you let off the gas with a regualr belt there's some slip, not much with 12ribs, but enough to cusion the blower impeller and bearings. With a cog there's ZERO slip. You let off the gas, downshift, anything - that impeller shaft gets yanked all over the place. You need that little bit of slip, my bearings had to be redone on my modded P1200 because of a cog. Heh, I've actually used traction compound myself on a Paxton - they sold some too I think.

 

Are you using the ProCharger spring loaded tensioner? Doesn't sound like it. It's a sweet but expensive piece - I had to buy one. Would love to see pics of your setup EFI is a good idea IMO, I can't imagine a blower working too well on a carb but I'm sort of biggoted towards FI myself! What intercooler? Sounds pretty sweet but I think I'll concentrate on just getting th eV8 into mine first then EFI and then maybe a blower if I'm crazy or can get a screaming deal...

[John Scott]

BLKMGK, Spring tensioner? I'd like to hear more? I'm tired of guessing the belt tension with only belt dust as a reference. Cogs are out in my opinion too. Must be perfectly aligned, harder on parts. Expensive! Need a bypass as well. I do run the big proflo. I didn't want to bend the throttle blades, and didn't like the idea of "stacking up" air in the compressor.. Sounds cool letting off a high rpm pass. Carbureted prochargers work great! Not as effecient as EFI, but very few if any complaints otherwise. Drives like any other good holley except instant starts year 'round w/o choke. That 1200 must push some serious HP! What are you running it on?

JS

[BLKMGK]

My P1200 is on a 351W in an '88 Mustang. Car isn't currently done and is sitting in my friend's shop waiting for him to install the blower, tune it etc. By the time I got the motor done etc. I was getting pretty tired of working on it and wanted to do a Z so I turned the car over to him. I promptly filled it's parking space up at home and he's sort of been storing it waiting for me to tell him to finish it I think I'm about ready to do just that as all this talk about it and how much power it "should" make is driving me crazy! When I'm done with the Z nearly every car of mine in the driveway will have a cage in it (lol).

 

As for the tensioner - if you've ever seen the tensioner on a serpentine belt in a Mustang you'd know what this looks like. Instead of a bolted down idler pulley holding the belt tension this is just a spring loaded version of it. I don't know that they're real cheap to be honest as I've forgotten what I had to pay. I'll look to see if any of the cars currently in the shop have one of these installed and take a pic for ya'. Mine's not on yet but maybe I'll take a pic of it too - the blower is mocked up on it's mount now I believe.