Does anyone make a good "aftermarket" harmonic balancer for the LT/LT4? One that absorbs vibration.

Thanks,
JTHVETTE

 

My buddy bought one of these for his 383 build, keep in mind this is only for an LT1 even though his ad says LT1/LT4. If you use it on an LT4 with the crank poisition sensor you'll have to have the snout cut back the thickness of the CPS to make your serp belt align right. That or either delete the CPS. It seemed like a quality piece and has been working fine. Also it's a fluid damper so it should eliminate all harmonics not just certain frequencies.

I can't remember who makes it but if I remember I'll post their website.

At 119.00 plus shipping it's hard to go wrong.

BTW, make sure you get on specifically for a Corvette, some companies don't know the Y body damper sticks out further than the F bodies and will try to tell you any damper for an LT based motor is the same. IT IS NOT!

http://cgi.ebay.com/ebaymotors/SFI-F...spagenameZWDVW

 

i,ve got an ATI balancer on mine. if you need the part # let me know and i'll find it

 

Yes, Iwould like to have that P/N.

Thanks,
JTHVETTE

 

the part # on my receipt says... ATI 917275 - ATI Y BODY LT1 $439.00

 

I've never seen a stock or aftermarket damper for an LTx engine for anywhere near that price. You are correct, the F and Y body dampers are not interchangable. Curious though, in their ad, they list it for years '93-'97 although those are the F body years for the LT1. The Vette years, of course, are '92-'96. Does the hub and damper separate? If not, engine removal would be required to remove or install it.

 

I can't remember if it's one or two piece (hub and damper) We installed it while the engine was on a stand so it didn't matter to us but that's DEFINATELY something to consider. The one in the E-bay ad worked perfectly on an Eagle crank, no cutting required. Email the guy, he was prompt.

Here it is CAT power engine parts...
Looks like it is two piece...
http://www.catpep.com/installation/d...fifluidpdk.htm

 

I am looking for a harmonic for a stroked LT4. The crank I used is a conventional type, From Gm. I got a complete rotating assembly from their performance stroker. Should be a hum dinger. Looking at the balancer on the eBay store looks like it is made for a conventional crank in a corvette LT* application. I would only need to secure the counter weight. Is this correct?

I am brand new to the boards. As new as I am to this engine design. I am putting it in a '67' Conv. Firebird. Any links, that I could be refered to would be a great help.

Looks like I need to start a thread about the install.
Advise for the harmonic would be appreciated.

Blessings

 

http://www.parts123.com/parts123/yb....Z5Z5Z50000050F

 

There's a couple of decisions to made with an LT4 stroker. Keep the stock balancer and have it neutral balanced (it may be already from what I read on these forums) assuming you're going to have your entire rotating assembly neutral balanced. This would also include the flywheel or flex plate, whatever you're going to use.

Install an aftermarket balancer, this brings up the question of the Crank position sensor. Since the LT1 doesn't have the CPS the aftermarket hub will be too long in an LT4. You could have the hub cut back the thickness of the CPS and all should be well.

Remove the CPS and have a tuner tune out the CPS (I've heard that can be done) and then any LT1 CORVETTE damper assembly should work.

Now this all assumes the crank gear (LT4) is the same thickness as as the LT1. It may or may not be I've never checked. The gear may be slimmer by the thickness of the CPS so the serp belt lines up correctly.

Using an aftermarket timing chain throws a whole new set of variables into the mix. Is the thickness of the aftermarket crank gear the same as an LT1 gear (should be) in that case would the CPS make the hub stick out WAY too far or would things jive?

At the end of the day you need to make a measurement with the stock stuff first of all. What I did was used a ruler from the block flange to the first rib on the stock damper and noted that measurement. Install your aftermarket damper assembly and remeasure that distance. Make whatever changes are necessary to make that distance the same. You're also going to have to use all the Corvette accessory drives in your 67 Firebird. Personally I'd switch everything to an F body based damper and accessories, they don't stick out as far. Toss the CPS, use a regular timing cover for the later opti and make your life easy. Then you can buy a damper for an F body car that might be cheaper yet.

I'd really like to know if the LT4 and LT1 hub and crank gear are the same thickness. If they aren't I bet there's a lot of 383 LT4's with aftermarket dampers out there with the belt riding cockeyed. Or they just let the misalignment shear off a rib making a 6 rib belt a 5 rib.

 

Interesting. But I'd hate to have a one piece set-up in these cars that would likely commit one to pulling the engine anytime it had to come off. Also I saw no brand or RPM specs for it. I would also have my doubts at that price whether it's any better or even as good as a stock one that's been balance checked.

 

For that matter if what's pictured is what you get I can assure you it won't work on a Corvette. That's looks like it's for an F body.

 

Thank you much for your reply, ALLT4. I am having to consider the many variables concerned with this......I don't know, stew? I came across most items affordably. I am dealing with an early style crank snout (different than the LT's). I bought the crank depot balancer on ebay, since it facilitate the hybrid. It is advertised as LT1/LT4, which would seem to indicate that they have already dealt (or should have) with the crank gear issue.

So many thing to consider, I am ignorant of most of these contingencies. Am I screwing up the electronic options?
Oh, the install only accommodates the vette set up, brackets etc.

Thanks for responding, ALLT4. I read your post and know you to be knowledgable.