help with 82 5.7 to vortec upgrade, flywheel question

[Bondo]

Re: help with 82 5.7 to vortec upgrade, flywheel question

Bondo,
The Sierra the part I recommended (above) is in their catalog described as:
"18-2172 Engine coupler: Used when replacing V6 or V8 engine with 2pc rear main seal with 3-1/2” crankshaft bolt pattern to a newer 1 pc rear main seal engine with a 3” bolt pattern."

Since the description matched what I (and Capitan828) are trying to do I bought it. Upon arrival I have verified that it fits my new crankshaft and is otherwise dimensionally identical to my old coupler so it mates with my R drive perfectly.

It works as advertised, I don't know what else to tell you.

Steve
View attachment 176443

Ayuh,... Of course the coupler works,...

The Outdrive's Input Driveshaft is what I'm talkin' 'bout....

You said yer's has the short shaft, 'n I'm sayin' that's the Wrong shaft, for that application...

It'll Run, but not for long...
It's only utilizing 1/2 of the available spline length...

 

[vznx1w]

Re: help with 82 5.7 to vortec upgrade, flywheel question

Ayuh,... Of course the coupler works,...

The Outdrive's Input Driveshaft is what I'm talkin' 'bout....

You said yer's has the short shaft, 'n I'm sayin' that's the Wrong shaft, for that application...

It'll Run, but not for long...
It's only utilizing 1/2 of the available spline length...

I think we are getting side-tracked here, I do not really know if my definition of a ?short" "Outdrive Input Shaft? matches your, but I can tell you that this boat has run for 29 years and 1500 hours on the input shaft and coupler that was in it from when it was built until the engine swap.

I am simply trying to make the point that Sierra makes a coupler to facilitate replacing an old GM V8 with a newer Vortec GM V8 and that it performs as advertised?it bolts to the new 1 pc seal crank while maintaining the same spline depth and bell housing clearance as the OEM. I thought this might be helpful to Capitan 828.

 

[capitan828]

Re: help with 82 5.7 to vortec upgrade, flywheel question

I think we are getting side-tracked here, I do not really know if my definition of a ?short" "Outdrive Input Shaft? matches your, but I can tell you that this boat has run for 29 years and 1500 hours on the input shaft and coupler that was in it from when it was built until the engine swap.

I am simply trying to make the point that Sierra makes a coupler to facilitate replacing an old GM V8 with a newer Vortec GM V8 and that it performs as advertised?it bolts to the new 1 pc seal crank while maintaining the same spline depth and bell housing clearance as the OEM. I thought this might be helpful to Capitan 828.

View attachment 176446

Yes, I already have this adapter on hand.

 

[81 Checkmate]

Re: help with 82 5.7 to vortec upgrade, flywheel question

Capitan 828 - You never said what your flywheel cover measures?

 

[capitan828]

Re: help with 82 5.7 to vortec upgrade, flywheel question

Capitan 828 - You never said what your flywheel cover measures?

Not sure what you mean by flywheel cover. But my flywheel does measure 14- 1/8"

 

[81 Checkmate]

Re: help with 82 5.7 to vortec upgrade, flywheel question

So you are saying your old and new flywheel are the same size? 14 1/8"

What i was asking is - What does your old flywheel cover I.D. Measure? If its like mine it will except the the new style 14" flywheel providing it will clear where the starter ( Straight or Staggerd) is on the newer style 1 pc rear main.

Post up if it all work's out and what you had to do.........As i may be doing the same on the Checkmate

Thanks and good luck!

 

[LorenHaus]

Re: help with 82 5.7 to vortec upgrade, flywheel question

Im upgrading and old 5.7 to a newer vortec and im not sure as to which flywheel I need to use. I know I cant use the original flywheel from the old 2-piece engine because its completely different. So can I use the flywheel that came with the vortec when it was in the pickup truck? Autozone says that its 14.13" OD. Will that fit in the old 82 housing when I drop the engine in? I already ordered the necessary coupler it needs when upgrading from 2-piece to 1-piece but I just dont wanna get stuck having to stop and order another flywheel when it makes contact with the bellhousing.

I AM from Michigan Motorz. I'm on this site for my own Silverton boat projects mostly but I see stuff regarding our company Michigan Motorz from time to time, so I'll help ya out. We have a 12?" flywheel made SPECIFICALLY for the 5.7L Vortec, balanced and all. Its for exactly what you are trying to do: convert an older 2P 350 to a 5.7L Vortec (8-bolt intake) engine. take a look here: 5.7L Flywheel (1985 & Earlier Engines, 12¾" diameter)

This will allow you to reuse your 12?" starter (strait across bolt pattern, using 1 long bolt and 1 short bolt) and your bell housing. Now you have to deal with the coupler. depending on your outdrive (shaft) as already mentioned, usually you can use the Sierra 18-2321 12?" triangular coupler.