LT1 flywheel question

Moderator: Moderators

LT1 flywheel question

Postby 76wagon » Wed Sep 21, 2016 8:56 pm

I have a T56 and clutch from an LT1 car and a 2 piece rear main seal engine. I know Centerforce makes a flywheel for this setup ($$$$$$$) but I got thinking. From what I understand the older engines had a larger flywheel bolt pattern than the newer ones and neutral balanced flywheels while the one piece rear seal engines have a smaller bolt circle and a weight cast into the flywheel. Correct me if I'm wrong, I've never seen the 2 side by side to compare.

I'm wondering what's stopping me from machining the LT1 flywheel to fit my engine- boring the centre hole, redrilling the bolt holes, machining the weight off and having it balanced. Anything I've missed? Might be worth trying since machine time is free for me and the LT1 flywheel is pretty much a paperweight right now...

Any thoughts?

Phill
Last edited by 76wagon on Thu Sep 22, 2016 9:05 pm, edited 1 time in total.
User avatar
76wagon
 
Posts: 373
Joined: Tue Mar 06, 2012 2:54 pm
Location: Kitchener, Ontario


Re: LT1 flywheel question

Postby spencerforhire » Thu Sep 22, 2016 6:57 am

There is an adapter you can buy to put a one piece seal crank in your two piece seal block. but that's somewhat of an extreme fix. I was going to say remachining the flywheel to fit would never work, but after looking at the pic, I think it just might be possible.
Attachments
cranks.jpg
cranks.jpg (28.09 KiB) Viewed 637 times
The "fleet"-
77 Vega Estate wagon- project(someday)will have TPI305/T-5, S-10 spindles/axles
72 Vega HB Drag Car -383/'Glide/9"(9.35@146.19)(5.94@117.28 1/8th)
76 Vega GT- 400/4spd/9" retired from active duty(rusty)
03 Silverado 2WD ex.cab (work truck/parts hauler)
04 Silverado 2WD ex.cab (retired)
06 Haulin' 20ft enclosed car transporter
93 Suburban- 350/4L60(retired)
00 Saturn SW2- wife's car
01 Saturn SC2- younger son's project
00 Saturn SL2- daughter's car
98 Saturn SW2- spare
and 3 more Saturn "parts cars"
Note- the very act of listing all of these has made me realize I have some kind of problem.....

Visit http://www.spencerforhire.ca
User avatar
spencerforhire
 
Posts: 2443
Joined: Mon Jul 03, 2006 9:02 pm
Location: Halifax, Nova Scotia

1972 Chevrolet Vega Hatchback

Re: LT1 flywheel question

Postby cosvega76 » Thu Sep 22, 2016 8:18 am

Phill,

How much distance is there between the larger diameter of the two-piece crank hub and the ODs of the one-piece crank bolt holes? Will there be enough meat to be safe?

Chuck
cosvega76
 
Posts: 2465
Joined: Mon Jul 03, 2006 8:36 am
Location: Moscow Mills, MO

1973 Chevrolet Vega GT

Re: LT1 flywheel question

Postby 76wagon » Thu Sep 22, 2016 10:13 am

I took a look at the flywheel when I got home last night- looks like more than enough room for the larger bolt circle, and the crank mating surface is machined way bigger than it needs to be. I figure since it will have to be neutral balanced I could rotate the new holes 30 degrees to avoid breaking into the old holes without a problem.

The one dimension I haven't been able to find is the diameter on the centre hole on an older flywheel. Does anyone know what it is?

I feel like there must be somethin I'm missing, it seems a little too easy...

Phill
User avatar
76wagon
 
Posts: 373
Joined: Tue Mar 06, 2012 2:54 pm
Location: Kitchener, Ontario

Re: LT1 flywheel question

Postby spencerforhire » Thu Sep 22, 2016 11:16 am

The 1 piece seal flywheel has a smaller hole, so it could be machined out. But by far the hardest part will be to get it to neutral balance.
The "fleet"-
77 Vega Estate wagon- project(someday)will have TPI305/T-5, S-10 spindles/axles
72 Vega HB Drag Car -383/'Glide/9"(9.35@146.19)(5.94@117.28 1/8th)
76 Vega GT- 400/4spd/9" retired from active duty(rusty)
03 Silverado 2WD ex.cab (work truck/parts hauler)
04 Silverado 2WD ex.cab (retired)
06 Haulin' 20ft enclosed car transporter
93 Suburban- 350/4L60(retired)
00 Saturn SW2- wife's car
01 Saturn SC2- younger son's project
00 Saturn SL2- daughter's car
98 Saturn SW2- spare
and 3 more Saturn "parts cars"
Note- the very act of listing all of these has made me realize I have some kind of problem.....

Visit http://www.spencerforhire.ca
User avatar
spencerforhire
 
Posts: 2443
Joined: Mon Jul 03, 2006 9:02 pm
Location: Halifax, Nova Scotia

1972 Chevrolet Vega Hatchback

Re: LT1 flywheel question

Postby Kenova » Thu Sep 22, 2016 3:21 pm

76wagon wrote:
The one dimension I haven't been able to find is the diameter on the centre hole on an older flywheel. Does anyone know what it is?

I don't know the diameter but I do know it is a snug fit, but not a press fit.

76wagon wrote:I feel like there must be somethin I'm missing, it seems a little too easy...

Phill

That's only because you're able to do the machine work yourself. :lol:

Ken
My other car is a Nova.
User avatar
Kenova
 
Posts: 1577
Joined: Sun Jul 02, 2006 9:46 pm
Location: Ontario, Canada

Re: LT1 flywheel question

Postby 76wagon » Thu Sep 22, 2016 9:39 pm

Ken- good point, sometimes I forget that not everyone can just bring this kind of thing to work and do it at break time. BTW, what part of Ontario are you from?

Spencer- I might have that partway covered. Just found out we have a really sweet grinding wheel balancer at work. That'll get me a static balance, I'm sure I can find someone in town to dynamic balance it.

Looks like I'm going to have a slow day at work Saturday, might have time to get cutting on this flywheel. All I need is the locating hole diameter. Can't seem to find it on the interwebs so I'll post the question on general discussion, hopefully someone has a small block in the garage and a mike or a caliper handy. People on this forum seem a little brighter than people on the rest of the Internet...

Thanks again
Phill
User avatar
76wagon
 
Posts: 373
Joined: Tue Mar 06, 2012 2:54 pm
Location: Kitchener, Ontario

Re: LT1 flywheel question

Postby Kenova » Fri Sep 23, 2016 9:06 pm

76wagon wrote:Ken- good point, sometimes I forget that not everyone can just bring this kind of thing to work and do it at break time. BTW, what part of Ontario are you from?
Phill


I often wish I had taken up the Machining Trade. Oh well, the General was /is good to me.
I'm up in Lindsay, about a two hour drive north east of TO.

Ken
My other car is a Nova.
User avatar
Kenova
 
Posts: 1577
Joined: Sun Jul 02, 2006 9:46 pm
Location: Ontario, Canada

Re: LT1 flywheel question

Postby Monza Harry » Fri Sep 23, 2016 9:42 pm

Kenova wrote:I often wish I had taken up the Machining Trade. Ken

NO YOU DON'T! Ok if you get a "Dream Job" like Phill, sure. I went in thinking I could work on my car parts after work, just like everyone else thinks. But after 10 to 12 hrs. the last thing on your mind is more machining, IF you can get on a machine, there aren't "spare" machines in most shops today, so after a 1 hour setup, you turn the machine on and some :cuss: :censored: apprentice needs the :censored: machine to do something you reminded him 3X to do before he took it off! :censored: :cuss: Most sentences are comprised of many, many 4 letter words sometimes compound 4 letter words! So in thirty two years of tool making, my car still isn't finished and it keps getting to be a bigger project with everything I learn that will fit the car! :bang: :bang: :bang: :bang: :bang: :bang: :bang: I have a headache! Harry It's hard to laugh when it is all you can do to stop yourself from crying! [that is a song lyric as best I remember it, from who? Beats me] "Edit" Well I was close: http://www.cduniverse.com/pursuit-of-ha ... 814513.htm that was around 1990+/-
I'm not a hoarder I'm a preservationist 78 Monza Spyder (Soon To Be 2+2 with Spoilers)
User avatar
Monza Harry
 
Posts: 2300
Joined: Tue Oct 04, 2011 8:50 am
Location: Windsor ON Canada

1978 Chevrolet Monza 2+2

Re: LT1 flywheel question

Postby cosvega76 » Sat Sep 24, 2016 6:58 am

Phill,

I have a small block 400 flywheel here; I measure the center hole at 2.487".

Chuck
cosvega76
 
Posts: 2465
Joined: Mon Jul 03, 2006 8:36 am
Location: Moscow Mills, MO

1973 Chevrolet Vega GT

Re: LT1 flywheel question

Postby 76wagon » Sat Sep 24, 2016 3:16 pm

Thanks for the help everyone. I managed to get it bored and redrilled today, plus I machined off the weight. Here's some pics.


Here's a before shot.
Image



All machined now I need to grind the clutch face and have it balanced and it should be good to go.
Image

I probably won't get the T56 into the car this year but at least I'm one step closer.

Phill
User avatar
76wagon
 
Posts: 373
Joined: Tue Mar 06, 2012 2:54 pm
Location: Kitchener, Ontario


Return to Transmission and Driveline Tech

Who is online

Users browsing this forum: No registered users and 2 guests