MrVette90l98mt

Hey guys its been a while since I've posted anything. I wanted to ask if anybody has come across or use this clutch kit from SPEC. I've done quite a bit of research on this conversion but could not find this kit mentioned anywhere...I cant even find it on their web site??? I only discovered this when I emailed them about if such a kit exists. They claim it is a direct fit for mating an LS3 to an OEM L98 ZF 6 speed (PN: SC05SLS-2)

quoted from SPEC email's response:

"We already make a conversion flywheel..pn SC05SLS-2. This unit las the LS3 crank pattern, larger LS 168 tooth ring gear and placement, and is made to take the ZF Vette/Camaro LT1 clutch with sprung hub disc. $889.20 package price witgh st2 clutch."

Regards,
David
SPEC, Inc

This sounds to good to be true, but man if it is true that would be sweet I know it is possible to mount an old 4 speed T10 to an LSx with relative ease (few parts: LS truck flywheel, larger SBC bell, and LS2 pilot bearing) so the same should hold true with the ZF bell because it bolts up to Gen 1 SBC. I will follow up with SPEC requesting pictures and or cross sections of this kit. My main questions are:

-What about the pilot bearing?
-Engine block fore / aft offset?
-Keep pull type pressure plate?
-No additional spacers or adapters?

Back story for wanting LS3 E Rod ZF 6 conversion (I'm in CA with smog):

My poor 1990 L98 most likely needs a major rebuild. For a while now I've been fighting coolant being displaced from the expansion tank to the over flow tank and not returning back to the expansion tank after cooling down. Not really thinking much of it I always thought I had a pin hole some where in the coolant circuit that would intake air from while cooling down but I have no coolant loss, its just being displaced. I've change the radiator cap and made sure the things where tight and after a change the coolant would stay in the expansion tank as normal but then would be displaced a week or so down the road. Recently I rented a block tester tool that checks for exhaust gases in the cooling system. Bad news is I get a constant stream of air bubbles when ever the engine is running and those bubble contain CO2. When I discovered this I then realized I tracked the car in this condition! So what ever cylinders where creating bubbles is likely cooked due to local over heating...oops

WVZR-1

It is on their website(flywheel), the clutch as a package is broken down for '93 and earlier ZF and the later '94+ ZF. The flywheel is a steel only and there's maybe 7 different clutch packages available.

The only place you'll find the reference is in the SPEC "CONVERSION COMBO" where there are multitudes of interesting engine/trans/chassis combinations.

Pick "conversion application" using the drop-downs from this page:

http://www.specclutch.com/products

cv67

Pull your plugs out and pressurize cooling system hope you dont have the notorious #7 head gasket leak they all do

mtwoolford

Jezze, far be for me to throw cold water on your plans, or suggesting you shouldn't do what you want to do...and I love the idea of an LS based engine in an earlier corvette, but please, please check with the Air Resources Board's regulations concerning engine swaps, and / or schedule an appointment with the local smog referee before you start down the road you're contemplating.

In short, and this is not legal advice so don't sue me but it is my information and belief (my lawyer makes me say that) that the replacement engine must have all the required emissions equipment as it did in the original vehicle which again I speculate would require the newer cat's, a new wiring harness that hooks up to all the LS sensors, and the LS computer to boot, plus whatever else is necessary to get the gauges and everything else controlled by the computer to work. And to keep things simple, and obviously they aren't, pull an engine from a "similar vehicle", i.e a corvette, and don't even think of using an automatic equipped vehicle as a donor for your project.

L98's are pretty bullet proof; I would look more to staying with a modified version of the L98, just my opinion.

SpedRacr93

Why don't you just move somewhere where freedom still somewhat exists? Make sure to bring the flag with you...

Seriously though. There was a guy on this forum a few years ago who swapped an E-ROD LS3 into an 86 (I think) and got it all approved in Khali-forn-ya. Can't recall his name though.

What bellhousing did Spec say to use? There is a Quicktime LS to ZF unit made but I've seen several people on here have issues with installing it. I don't keep up with the posts enough to know whether or not it was resolved.

MrVette90l98mt

There really isn't any point as I have already confirmed the bubbles and air being pumped into the expansion tank are composed of exhaust gases...1 of 3 things: Cracked head, block, blown head gasket, or all of the above. My last track day at Sonoma 9/27/15 I was fighting this issue of the coolant being displaced into over flow with foam venting from the cap...(4) 20 minute sessions flat out with this condition although it never indicated it was over heating. I'll try and post a video photo of the block test.

MrVette90l98mt

That's the beauty of the LS3 E-ROD, It comes with the all important C.A.R.B. EO# for OBD1 (pre '95) Vehicles

it's essentially a full turn key package with all smog stuff. All you need is a fuel pump, cat back, mounting gear and accessory drive and your golden They even have an LSA Super charged E-Rod 556HP!

All things considered the LS3 E-Rod is the most cost effective way. (time, warranty, reliability, daily performance, efficiency, better handling, smog, etc. The only down side is up front cost. It's coming out to be around $10K parts only with me doing the all the labor. Good thing I have good credit and qualify for a low interest rate personal loan!

P.S. you can tack on another $4K for a ZF rebuild

MrVette90l98mt

LOL, I know right!, CA is pretty ridiculous when it comes to smog...they are not even remotely reasonable....they would rather you scrap an old car and buy a new one rather than update an older platform. Updating is by far more "green". Think about the amount of energy required scrapping and then having to rebuild a replacement. The only thing that they should care about is what comes out of the tail pipe and off gassing that is controlled by the evap system.

I think I stumbled across that thread you're talking about. Not too bad overall, it looks like the cats will have to be oriented vertically to fit in the trans tunnel.

SPEC got back to me but they didn't specifically answered all my questions. They said they made a custom flywheel and used their off the shelf clutch spring damper disk and Pressure plate that still retains the stock hydraulic system as well as the pull type fork...no after market bell housing or having to convert to a push type system! I saw that thread about how the Quick time bell housing is a "should fit" design. The only mod that was mentioned was having to grind the stock ZF bell housing in some areas to make clearance for the 168 tooth starter ring gear the LS3 uses. I figure I'll do more research and possibly green light this project in a month or 2. Apparently Corvette Central is also working on some sort of LSx conversion kit. No specific details just they announced it on Facebook 3 months ago with no update

MrVette90l98mt

Here are some pictures of the problem:



After a few minutes running (engine off)





Warm running, Coolant is less than a year old





test fluid color before and after (exhaust gases turn the fluid yellow green)





Clean oil, no coolant in oil.

TurbineSurgine

I may have to try this conversion, I have a ls3 about to go in and all I need now is the bellhousing/clutch components. I was only aware of the quick time bellhousing and zfdoc zdapter plates to do the conversion.

MrVette90l98mt

That was my belief as well, I came across a youtube video and a Hotrod article on how to mount an old school T10 4 speed (with a fly wheel and a pilot bearing) to an LS. So I thought to myself the same must hold true for the ZF that mounts to a Gen 1 SBC...turns out it can

I've been talking to David Norton about this conversion. Tell him "Savagex32" sent you. Awesome guy and replies back with info quickly. Luckily for me I replaced my clutch with a SPEC kit about 10,000mi ago so all I need to hook up my ZF to an LS3 is the flywheel and a die-grinder (to clear some areas for the 168 tooth ring gear)

I'm still in the planning stages for my conversion it'll be a few months....$$$$$ Please, by all means get in touch with David, get more info, test fit this flywheel and tell me if it works

TurbineSurgine

Yea I bet you would like for me to be the guinea pig.
My concern would be grinding on the bell housing, the areas that would need clearance are around bolt holes that mount to the block. Since the zf uses a c beam instead of a typical trans x member it may be a bad idea to remove material around a area where additional stress would be present in addition to only using five of six bolts to hold it on.

I don't know how much development and testing went into this flywheel but there are many things to consider other than getting a clutch to attach to a flywheel. I may go ahead and try it out in addition to adding some bracing to help support the gearbox. I know one thing, im ready to get the car back on the track

bogus

The score:

If you use a CAR BASED engine, from the same or newer year, and maintain all emissions from the newer engine, you are ok in CA.

Now... I have been reading the smog exceptions and there is an interesting term... "light duty usage". This might allow for light duty truck engines to be used for car use. Considering they are the same damned thing...

I am going to ask CARB directly at some point, and when I get the answer, I will be sharing it...

Oh, and these regs match EPA.

MrVette90l98mt

I sure would! If anything, depending on how much you have to grind, my only concern would be the bending motion at this joint. 5/6 bolts plus 2 dowel pins (if they line up) should be ok for all other forces. LSx use the same bolt pattern so we shouldn't have to grind much off.

I found some old cell phone pics to help visualize things out. This is about 5 years ago when I did my clutch. (pardon the crappy quality)






ZF bell housing





L98





Stage 2 kevlar





Pull type pressure plate

MrVette90l98mt

I took a smog class back in 2008 and this was the case. It shouldn't have change, but please let us know the current rules. I just wonder how much a referee station charges for the "engine change" inspection.

TurbineSurgine

Well today I did some test fitting with a stock ls3 flywheel and zf bellhousing. I bolted up the flywheel then tried for the bellhousing, it would not go on. I stuck two long bolts through to align it correctly and find where the interference is. The lower half the bellhousing will not clear the teeth, there is not enough material to just grind away and make fit. It would take lots of chopping and magnesium welding to make it work and in the end it would be just better to buy the quicktime bellhousing. The zf bellhousing is going to require a 158 tooth flywheel, I heard mcleod makes one for the ls but you still have to figure out a starter to go with it. Sorry for the bad news, I really didn't want to have buy the QT bellhousing but there is not much choice.

MrVette90l98mt

Well ain't that a steaming pile of dog dirt Just to make sure and to understand correctly, the problem only exist with the lower portion of the bell housing (bellow the bolts) with the 168 LS ring gear? Does it clear around the 5/6 mounting bolts?

sure glad we find out now rather than $$$$$ into the whole conversion! Now we know why the quick time bell housing exists, lol! I could never find the reason why you need a new bell housing...that's why.

Now, more out of the box thinking:

does anybody know anybody that makes a bigger starter pinion gear for LSx starter motors for use with 153 flywheels? A quick search on summitracing website says no.

Universal starters motors that might work?

Cut away the interference and make a sheet metal shield?

So really the only options right now are Quicktime bell housing and full push type conversion clutch kit. (which may still be a trim to fit, search the forum for more info)

or

ZF doc's LS Camaro bell, clutch kit with adapter plate...is this even available?

I know Corvette Central is up to some sort of C4 LSx conversion kit...still no details 3 months since their announcement They told me they are collaborating with Petris Enterprises...they must be good if they charge upfront for technical email inquires! End of march may be when more info becomes available.


I guess I'm stuck playing the waiting game

aDigitalPhantom

There are no problems fitting a push type clutch in the quicktime bellhousing. There are a lot of LS clutches that will work for this. I'm using an LS7 clutch kit I got from SDPC.

I've been trying to get the information I have on this posted but something keeps stopping me. It may be misplacing parts, forgetting to take pictures, being sick, or just simply putting it off.

I can post a picture (or more) later with the bellhousing bolted to the block, the clutch installed, and clutch fork and throw out bearing in place. I'm not sure if they would be useful for non-lt1 cars, but I can also get a fix pictures of the engine mounts.

MrVette90l98mt

That may be true but I read through a thread on this forum about somebody's LSx build and the quick time bell housing did not mount flush against the ZF trans case and required a pocket to be milled...for a $600+ part that should not be the case and needs to be a direct fit. Maybe he got one of the early parts that didn't have this revision?

https://www.corvetteforum.com/forums...ts-list-6.html

I'm all for more pics and information! please do!

MrVette90l98mt

Would you say the following mods needed to make the 168 LSx ring gear fit into the ZF bell would end up making the bell housing looking like:

Grinding the interior of bell housing only:



Or cutting the lower half similar to this:



from your picture it looks like this would be the case.

New thought- Summit sells a starter Motor for 153 and 168 tooth flex plates, but it does not say its for LSx engines. SPEC told me this flywheel can be made with a 153 ring gear. (Summit Racing® Protorque Starters SUM-820323)











On another thread I read when using a 153 flywheel on a LSx you may run into clearance issues with the oil dip stick. Does anybody have any experience with starters and 153 flywheels / flex plates? Post 6 on another forum http://ls1tech.com/forums/conversion...-flywheel.html I'd rather make a custom starter mount than mod a quick time bell!

My other car is a 2009 Pontiac G8 GT with an L76 6.0L, I'll have a look and see how tight things are with LSx starters.