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View Full Version : Questions about the LT5 crankshaft. What makes it so unique?


5ABI VT
07-30-2015, 11:54 AM
Curious about the LT5 Crank. Ive contacted a few Crank suppliers and 2 already have told me they can build me what I want. I haven't asked the cost yet :cry: ... but I was expecting a straight up 'NO' reply based on what Ive read about LT5 cranks over the years being pricey and limited etc etc.

so what makes the LT5 so special? is there a reluctor wheel or something like that that adds to the cost?

My idea for my build will be as big of a bore as possible and as long of a rod as possible with an extremely lightweight crank, rods and pistons etc. Hollow or ti valves (32 valves is awesome until you have to buy new ones lol). If I do shell out for a build I will look at custom billet manifold options as I want to do something like an individual tb setup eliminating the Injector housings and Plenum entirely for short stacks and a large volume plenum... massive cams, 1500 idle is fine...;)ideas ideas..

:cheers:

tpepmeie
07-30-2015, 12:47 PM
so what makes the LT5 so special? is there a reluctor wheel or something like that that adds to the cost?

The issue is that there are no existing cores or patterns out there. Only Bryant and Moldex have written CNC programs to make the crank from billet. What you'll find is that any of the major crank manufacturers have the capability to reverse-engineer the OEM crankshaft and create the program. But that takes time, and thus the price is really really high.

Yes, there is a reluctor wheel in the center. And the oiling drilling is unique, as is the snout.

From what you've described, I'd recommend a 3.75" offset ground stock crank, and 6.125" rods w/ 1.025" compression height pistons. The stock crank is a high quality piece.

Sounds like you'll want a set of cam cores, too. I can help with that :wink:.

Jagdpanzer
07-30-2015, 02:01 PM
The LT5 crankshaft design is somewhat unusual compared to most V8 cranks. Main difference is the lubrication of all main and rod bearings is done via interconnecting oil distribution channels drilled the length of the crankshaft. Main thrust bearing location is also different than most as is the ignition timing wheel reluctor slots that you mentioned. Consequently there are quite a few more precision machining steps required to produce a LT5 crank compared to a typical small block Chevy or others like it. To my knowledge there are only two experienced aftermarket suppliers still doing our cranks, Bryant and Moldex.

Hib Halverson
07-31-2015, 02:12 PM
Curious about the LT5 Crank. Ive contacted a few Crank suppliers and 2 already have told me they can build me what I want. I haven't asked the cost yet :cry: ... but I was expecting a straight up 'NO' reply based on what Ive read about LT5 cranks over the years being pricey and limited etc etc.

so what makes the LT5 so special? is there a reluctor wheel or something like that that adds to the cost?

My idea for my build will be as big of a bore as possible and as long of a rod as possible with an extremely lightweight crank, rods and pistons etc. Hollow or ti valves (32 valves is awesome until you have to buy new ones lol). If I do shell out for a build I will look at custom billet manifold options as I want to do something like an individual tb setup eliminating the Injector housings and Plenum entirely for short stacks and a large volume plenum... massive cams, 1500 idle is fine...;)ideas ideas..

:cheers:

"Ideas, ideas"?

1. A really big check book
2. A really good engine controls engineer

XfireZ51
07-31-2015, 02:48 PM
Todd,

Ever sell your setup?

5ABI VT
07-31-2015, 02:49 PM
"Ideas, ideas"?

1. A really big check book
2. A really good engine controls engineer

I keep going back and forth.. I know how motor builds go. Have to draw the line somewhere or else it blows the budget astronomically. That callaway aerobody and rebuilding my wheels is starting to look like a much better plan :neutral:

tpepmeie
07-31-2015, 03:26 PM
Todd,

Ever sell your setup?

Which parts? I'm in the process of rebuilding it right now. Tried to sell the entire Build 1 valvetrain, incl. camshafts. I think I will put it together with those again, then upgrade later. The issue is not new cams (I've got billet cores), but all the custom complimentary parts which need to go with it--springs, retainers, seats, buckets, etc. Only going to do that if I can sell the other set.

Karl
07-31-2015, 03:29 PM
Or call this guy up.

https://www.youtube.com/watch?v=Zx4dnUe8CdU

https://www.youtube.com/watch?v=hRWEA9aMOl0

https://www.youtube.com/watch?v=hRWEA9aMOl0

I think this is the engine. I doubt the crank is stock

https://s-media-cache-ak0.pinimg.com/originals/8e/db/c3/8edbc3dcd0aefe41ffcfac056e4535b9.jpg

XfireZ51
07-31-2015, 03:39 PM
Which parts? I'm in the process of rebuilding it right now. Tried to sell the entire Build 1 valvetrain, incl. camshafts. I think I will put it together with those again, then upgrade later. The issue is not new cams (I've got billet cores), but all the custom complimentary parts which need to go with it--springs, retainers, seats, buckets, etc. Only going to do that if I can sell the other set.

Todd,

Yes the first build parts. Would make an interesting presentation for the Gathering next year.

rkreigh
07-31-2015, 03:54 PM
Or call this guy up.

https://www.youtube.com/watch?v=Zx4dnUe8CdU

https://www.youtube.com/watch?v=hRWEA9aMOl0

https://www.youtube.com/watch?v=hRWEA9aMOl0

I think this is the engine. I doubt the crank is stock

https://s-media-cache-ak0.pinimg.com/originals/8e/db/c3/8edbc3dcd0aefe41ffcfac056e4535b9.jpg

stock crank is forged and all you need.

with the turbos displacement isn't necessary and the short stroke can work out well.

Hg sealing on the open deck block is more of an issue. I think the AES liners and short block may help there.

that is one sexy beast! ya baby ya! (A Powers)

FU
08-01-2015, 10:05 AM
I doubt the crank is stock



That crank is a Velasco billet.

Karl
08-01-2015, 03:47 PM
That crank is a Velasco billet.

Is that the lt-5 by Nelson racing?

FU
08-01-2015, 04:05 PM
Is that the lt-5 by Nelson racing?

Correct, a Velasco billet crank with a 3.750 stroke.

XfireZ51
08-01-2015, 05:27 PM
Correct, a Velasco billet crank with a 3.750 stroke.

Are they still even doing that any longer?

FU
08-01-2015, 06:08 PM
Not sure about Velasco making cranks Dom , but I cant see why not.. That crank is a work of art ,knife edged and shaved instead of being drilled for counter weight. Sharp !

Karl
08-01-2015, 07:47 PM
Are those factory or aftermarket spark plug wire clips?

danonasch
08-08-2015, 01:05 AM
This engine is a work of art and Nelson Racing is the top builder in the Country! If I can make up my mind to either build my car into a ground up twin turbo beast! The Black on Black is the way to go, that's my car my engine is all polished up to look like chrome. This is much like a piece of Jewlery and so well done! Must have 40,000 in just the engine bay with the custome plenum and throttle body! Love it and I want to do this to my car! If you own this post some more pictures please! Dan Onasch