• Got the Contributing Memberships stuff finally worked out and made up a thread as a sort of "How-To" to help people figure out how to participate. So if you need help figuring it out, here's the thread you need to take a look at -> http://www.corvetteflorida.com/forums/showthread.php?t=3581 Thank you, everyone! Rich Z.

427 engine (part 2) - RHS block

I'm surprised you have any hair left with all you've been through with this car. I feel for you. Question: I know you have a Centerforce clutch. Are ALL the parts Centerforce? Flywheel, PP, Slave Cylinder? Just wondering if something isn't matching up. When the Fidanza clutch in my Cadillac started having problems I did a lot of research finding that using the factory slave for the LS7 clutch that I went to had caused issues in other Caddys, I was referred to this guy, Mike at:

http://www.eastcoastvette.com/p-392...version-2005-2013-c6-z06-zr1-grand-sport.aspx

He knows his stuff. I got the complete kit from him and when I had SS Performance install it they said that they were expecting to have to shim it to make it work. But there was no need, it all worked as he said it would. Just throwing this out there. Good luck in any event.
 
85vette said:
I'm surprised you have any hair left with all you've been through with this car. I feel for you. Question: I know you have a Centerforce clutch. Are ALL the parts Centerforce? Flywheel, PP, Slave Cylinder? Just wondering if something isn't matching up. When the Fidanza clutch in my Cadillac started having problems I did a lot of research finding that using the factory slave for the LS7 clutch that I went to had caused issues in other Caddys, I was referred to this guy, Mike at:

http://www.eastcoastvette.com/p-392...version-2005-2013-c6-z06-zr1-grand-sport.aspx

He knows his stuff. I got the complete kit from him and when I had SS Performance install it they said that they were expecting to have to shim it to make it work. But there was no need, it all worked as he said it would. Just throwing this out there. Good luck in any event.
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From what I recall, the flywheel was the one in the car when it went to the Chevy dealership, but reground and resurfaced. Now, I'm trying to think back exactly which flywheel was in there at the time. Harwood put in an aluminum Fidanza flywheel. Then when it was discovered by Aaron Scott that the Fidanza clutch that Harwood put in there was an underpowered one, and not the higher model I actually paid for, Harwood had to come up with the clutch I paid for. Which Aaron then installed I can't recall if the flywheel was replaced or not at that time, but I think it was because I really didn't like the aluminum one much. It was too tough, with all the other problems, pulling the car off the line with that light flywheel.

In any event, when the drivetrain failed because of the Pfadt oversized driveshaft, Shane at the Chevy dealership did the work and I'm sure he said he was going to have the flywheel resurfaced, or did he say he was going to replace the driveshaft with OEM because of all the other components getting damaged? My memory is hazy about that point. In any event, the pilot bearing (according to the part number on the invoice, he put a bearing in instead of a bushing) and the throwout bearing was OEM as well. Interesting to note, that the throwout bearing looking like it was my original one from when I first took the car into Harwood's shop. I have no idea why Aaron would have left that in the car when that second Fidanza clutch was changed out.

Got too many details starting to turn to mush in my head over this, I guess. Most of it is likely documented in this thread, though, so I guess I could find the answers if I dig hard enough.

Addendum, I checked the invoice from the Chevy dealership and it states that a used flywheel that was resurfaced was put in the car. Not real crazy about that, but it is what it is. In any event, at the next upcoming clutch install, that flywheel is coming out of there anyway.

I believe the path I will be taking is to have the clutch assembly, flywheel, pilot bushing, and slave cylinder/throwout bearing ALL replaced. Even if I can find someone who can accurately diagnose the problem and if it comes to something like a torque tube bearing or transmission input shaft bearing, I STILL might have that clutch stuff replaced anyway, since the drivetrain would mostly have to come out anyway. Heck, if someone says it could be either A, B, or C, I might just say replace them ALL and be done with it. It will cost me a couple of social security checks, but heck, I'm just tired of the headache and want my car so I can drive it with a smile on my face. Even while testing it today, when those turbos kick in, it definitely puts a smile on my face even with this nagging headache.

Oh, and yeah, I guess I can blame the lost foliage on my head over this crap. I guess any excuse will do.
 
What type of engine block do you have? Just curious. I have an LSA clutch assembly that was a take off from a Caddy CTS V. The 556 HP variety.
 
Just to answer your question, it's a 427 block made by RHS.

And yeah, that torque tube certainly does complicate a clutch change. Even worse would be to just have a $10 pilot bearing go out on you and be slapped with the labor bill just to replace that little inexpensive part.
 
I took some video when I took the car out for a test drive the other day to test for evidence of a bad pilot bearing. But as you will see in the video, the drive was pretty much noise free. Except from the exhaust, of course... :hehehe:



https://www.youtube.com/watch?v=FM3b5ol3bQo&t

Actually, except for a minor squeal when coming out of my driveway, you would never think there was a drivetrain noise problem at all.

Oh yeah, this is the first time I have taken any video with the new GoPro Hero 6 camera I got a while back. Seemed to do a pretty decent job. I guess image stabilization was enabled, because the video seems very smooth and stable to me.
 
85vette said:
Sounds good!
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Thanks!

Yeah, it does sound pretty good. A friend of mine has a 63 Chevy Impala that he is restoring and modifying. He just loves the sound of that C5Z and badly wants his car to sound the same way. I've never heard the car from the outside, and he says I REALLY need to do that.
 
I agree! The only times I heard my Caddy and not been driving it was when my wife would drive it to work when her car was getting maintenance done on it and MAN did it sound great! I could only imagine how it would sound if she was getting on it.
 
Looking through some threads concerning Centerforce clutches making noises.

https://www.corvetteforum.com/forum...2-bad-move-on-my-part-centerforce-clutch.html

Thinking that I would improve my car for HPDE's I replaced my stock clutch with a Center force clutch. My Tech said that he's used it on all his customers cars without a problem but I should know that there will be some chatter for a time period, the chatter is getting less as expected. With the Center force I'm hearing all sorts of rattling noises at idle with the clutch let out but goes away when the clutch is depressed. Also, if I don't let the clutch out and add throttle perfectly I hear a metal grinding and scraping noise as I roll forward or reverse but goes away as rpm increases. I never had this happen with my stock clutch and I've been driving manual transmissions for over 30 years and never had this happen. Has anyone had this happen
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I spoke with Centerforce and my tech, both stated that the rattling at idle and the metal on metal noise as you release the clutch and give it throttle are totally normal.
Click to expand...

So, Centerforce says it is "normal", eh? Maybe for a Centerforce clutch it is, but not what I want to be hearing when I am driving my car.
 
85vette said:
Sounds like the only fix for that would be replacing the clutch. Are you going back to GM parts?
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It will depend on who would be doing the work for me. Generally, if they provide the clutch, they probably would warranty their work. But if I carry it in, having bought it elsewhere, then more likely than not, they would not cover any failure associated with that clutch.

Of course, the last time I had the clutch replaced, it was at a Chevy dealership and although they insisted on using the Centerforce clutch, I was told at the beginning that they would not warranty anything because of the highly modified nature of the car. I accepted that, because I understood their position, as well as pretty much being stuck between a rock and hard place. I had limped into the service department in first gear when the clutch slave cylinder had failed on my way there. The combination of the Pfadt oversized driveshaft and Aaron Scott leaving bolts loose (and missing) on the bell housing to the block had finally reached a head, I guess.

So, as I mentioned, it all depends on the policies of whoever I can get to tackle this problem for me. And it doesn't appear that I am going to be overwhelmed with options, neither.

I probably should get the car dynoed to see exactly how much power it is putting out so I would have a better feel for what level of clutch I really need. I never noticed the Centerforce clutch slipping on me, but then again, I have NEVER dumped the clutch for a dragstrip type run, neither. So maybe it really doesn't matter that much. But generally speaking, I would rather over spec a clutch than under spec it.
 
Not sure where the closest dyno is these days. I think Trans Am Worldwide may have the one from SS Performance since they bought the building they were in. I guess you could call them and ask. I'm thinking they just use it to tweek those engines in the Trans Am's they build. I know one model makes 840 hp and rumor has it they have a 1000 hp one also. Not sure if it's available to the public. I'll ask my son, he used to hang out over there all the time.
 
I've been conversing with RPM Transmissions recently. I had been reading up on indexing the bellhousing to the engine block, thinking that could be part of the problem, but they indicated that it likely was not since I am using the OEM bellhousing. They then asked me what clutch I had in the car, and I told them the CenterForce Dual Friction disk, and provided a link to the YouTube video I took to display that noise I am having. The guy replied that this noise is normal for that type of clutch and not a problem.

Well, maybe not, but not something I want from MY car. Reassuring to think that something isn't subject to eventual destruction with the noise being a warning shot, but still.....

So maybe just putting in a different clutch might solve the problem. Thing is, WHICH different clutch? I guess the thing I need to do is to see which brand of clutch whatever shop works on my car likes and will stand behind. As long as they guarantee it and their work, then no problem. So in the meantime, I guess I've got to do my own research to produce a short list of possibilities that will be acceptable.

Anyway, after I recently changed the oil in the car and started it up to check for leaks, I noticed a clicking noise coming from the engine compartment. Not fast enough to be coming from the actual engine, sounding more like something on the serpentine belt or maybe something in one of the pulley grooves somewhere. So got to take a closer look at that when I feel ambitious enough. I did check the belt for cracks or frayed areas, and it looks fine from what I can see. :shrug01:
 
I asked earlier about what engine you had. I knew you had an aftermarket block but I was wondering if it was an LS6, 7, 9, or LSX design since the flywheel bolts differ. I guess the first thing to determine is what amount of hp and torque it will have to handle. At the same time, I know you want it to be streetable. I had issues with the Fidanza clutch in mine, not because of the clutch, but that 14 lb. flywheel made you have to drive it like a racecar. Even with a lot of hp I know you don't hammer your car so I doubt you would need the baddest clutch on the planet. I was much happier with the way my car drove when I went to the LS7 clutch with the heavier flywheel. It didn't rev as quickly but I wasn't drag racing it anyway. It never slipped under full throttle and we're talking a nearly 4000 lb. car, more than that with my family and some luggage in it.
 
Well, I'm not exactly sure. From what I remember, the block has LS7 style heads and LS7 style intake manifold. But the headers are from when I had the original LS6 engine and they seem to mount up just fine to those heads. As for the crank, I am presuming everything in the block is compatible with the LS6, since nothing was changed to make it work with something other than that.

Push come to shove, what exactly IS different about the LS7 compared to the LS6 in relation to what the block has bolted onto it? Offhand it appears that the pilot bearing is different, being larger in diameter and fits further away from the engine in the end of the crank than the one in the LS6, which would mean that the input shaft to the torque tube would have to be shorter, since it would engage the pilot bearing differently. For the LS6 the pilot bearing is smaller, and fits further back in the end of the crank. So is the entire torque tube different for the LS7 than the LS6 or is it only the input shaft that might be different? :shrug01:

Are my LS6headers inefficient being used with the LS7 exhaust ports on the heads? :shrug01:

Would LS7 style headers fit the body and frame and the rest of the car of the C5Z? :shrug01:

The LS2 throttle body needed a harness adapter to work with the LS6 wiring, but seemed to bolt onto the LS7 style intake manifold just fine. Or so it seems. All of the accessory brackets seemed to bolt on just fine to the RHS block, which is actually a much different case than when Harwood got in that piece of crap World Products Warhawk engine. He was having to do all sorts of "minor fitment to get them to fit properly on that block.

Hopefully anyone who works on my car will be able to tell what is needed by eyeballing what is already on there. If they can't, well, that could be worrisome to me.

Anyway, I originally wanted a light flywheel in the car, but after driving it for a short bit, I too just did not like it. I just had to rev it too high to keep the engine from stalling out from a dead stop. Caused me to burn some rubber several times as a result. I definitely want a heavier flywheel. I like the way the C6Z drives and it has a pretty hefty flywheel on it. So no more of those light aluminum flywheels for me.

As for horsepower rating, I really don't know as I have never really had it dynoed. Aaron Scott said he did, but come to find out that with the LS7 throttle body he put on the car, it is pretty much impossible to get the throttle over something like 80 percent without getting a REDUCED POWER fault. Yet he claims that he did. But I have my doubts.

When Mike Carnahan was down here to do the preliminary tune on the car, after he drove it for a bit he said he would estimate that it was putting out 850 rwhp. I believe he is pretty experienced with high powered vehicles, so my guess is that he would have to be pretty close with that estimate, and that is what I am going by.

I'm sure I want a twin disk clutch as that just seems to be the way to go. Shane at (what used to be) Champion Chevy was dead set against the twin disks, which is why I got the single disk Centerforce put in the car. If that clutch didn't squeal like cats being skinned alive sometimes, it would actually be an OK clutch, it appears. Never had it slip on me, and it catches pretty well. I dunno, maybe something to do with the resurfaced used flywheel has something to so with the noise.

In any event, the clutch is going to be replaced, no matter what. Which means a new flywheel, pilot bearing, and throwout bearing too. Hopefully nothing else will need to be replaced.

If that gets rid of the noise, then that will be a BIG step in getting this multi year long headache finally behind me.
 
Well, you're going to need to know how many bolts hold your flywheel on to make a determination of what to go with.
 
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