Hope someone has an answer for me please, I’m currently building a sbc 383 and found a new camshaft that was supposed to be in a factory Gm 383. Pert number 19210723. It was supposed to be a factory pull out as the engine builder wanted something different. Upon closer inspection there appears there are no part numbers on it. I thought that was pretty unusual for a Gm camshaft. The only id I see is it’s marked with blue paint! Can anyone comment or confirm . Thanks

 

No. Not without numbers.GM never made a factory 383.

 

Well, they kinda do... it's available as an over-the-counter crate motor. You're right though that none ever came in any vehicles. And, GM's 383 isn't exactly the same as one we might build; instead of the typical stock 400 stroke, its is slightly longer, which is how they get a 383 out of a 4.000" bore.

Last I knew GM was getting most of their cams of that general sort from Crane.

If you research the "HT383" you might be able to get some specs.

 

I just checked the 2024 Chevy Performance Parts Catalog. 19210723 is the cam part number listed for their "SP383 Turn Key" complete motor. It is shown on page 140 of the catalog. The cam specs are listed as follows:

Hydraulic roller
Valve Lift (in): .509 intake / .528 exhaust
Camshaft Duration (@.050 in): 222° intake / 230° exhaust

As SofaKingdom said, Crane made Chevy's performance cams. I checked a 2013 issue of the Crane Master catalog and found part number 109831. The specs match the Chevy cam and also lists the following: Lobe Separation Angle: 112 Degrees, RPM Range 2000-6000, Fair Idle.

One interesting note is that the HT383 is listed with a different cam as follows:
Camshaft Type (P/N 14097395): Hydraulic roller
Valve Lift (in): .431 intake / .451 exhaust
Camshaft Duration (@.050 in): 196° intake / 206° exhaust

Fred

 

I do believe Gm made an aftermarket 383 . Aftermarket ps like summit offer several different cubic inches.

 

Thanks for checking for me ! The guy I bought it from swears it’s a383 sbc with that number. Still I’m questioning the no part number?

 

You could install it in your block then degree the cam to determine the specs. .509/.528 Valve Lift comes to .339/.352 Lobe Lift with 1.5 ratio rockers. The Chevy and Crane catalogs both say 1.5 ratio rockers.

Hope this helps,
Fred

 

Easiest way to know if it's a 383 without stripping it down to check part numbers on the crank and rods is to look at the balancer and flywheel/flexplate. Unless GM decided to use an internally balanced crankshaft in their non production 383 engines, they will be externally balanced just like the 400 engines use using external balance weight. The end of the crankshaft will also have a dowel so that the balancer/flexplate can only go on in one position.

There's nothing saying GM used internally balanced cranks to make their 383 engines either.

 

The last 4 digits of the part number will be stamped on the rear end of the camshaft. The SP383 has a GM supplier clone of the old Crane made GM 846 cam.

12370846 Hydraulic Roller Design
This hydraulic roller design contains eccentric for mechanical fuel pump. It is for off-road use only. The duration at .050" tappet lift (intake/exhaust) is 222/230; and maximum lift with 1.5:1 rocker ratio (intake/exhaust) is 509/528. Valve lash is zero/zero and lobe centerline is 112 degrees.



14097395 cam from a 2017 GM built HT383 Mercruiser boat engine. The HT383E balancer uses a bolt on counterweight and all 1-piece rear seal small blocks are externally balanced on the rear.

 

HT383 balancer is a 12498008. Counterweight is bolted on.

 

I have the HT383 short block.

On the back of the engine in the bellhousing area, it has this ID tag...(picture 1 below)

It also came with the SP383 cam. There was no p/n on the cam oddly enough, but Scoggin Dickey Chevrolet (where it came from) said it was the SP383 cam, and I also verified it against the specs on that cam with the degree wheel. The only markings on the cam were V119 216 (picture 2 below)

Also, the only 383 that GM ever built was crate engine that uses the mid-90's Vortec blocks with the composite timing cover. If its not a Vortec block, it is not a GM 383.

But you can also measure the stroke... it should be 3.800 (not 3.750). That 3.800 crank is a unique GM crankshaft.

 

thanks that’s a great idea and exactly what I’ll do !!! I appreciate the suggestion.

 

I have never seen a GM cam that did not have numbers somewhere on it. Most of the GM performance cams are marked on the rear of the cam. Some are between the fuel pump eccentric lobe and #1 exhaust lobe.

 

Literally googled the cam in question. Found a picture with the last 4 of the part number right on it.