My fresh 1965 283 with 268 Comp Camshaft

[Lugnutz65]

It’s been a few months since my last post.
You may recall I recently introduced you to my 1966 Jasper rebuilt 283ci with the GK 930 cam. Pistons are 0.040 with powerpack heads, cast iron intake and Rochester 2Jet carb. Looks stock. Runs great. Sounds great.

Up for comparison is engine #2.
Freshly rebuilt 1965 283ci with 0.060 hypereutectic pistons, powerpack heads, Comp Cams 268H flat tappet cam, cast iron intake and Rochester 2Jet carb. More details at the very bottom of this post.
Just broke in the engine on 4/16/22. A run stand is the way to go.
Here’s the video of the first break-in run.

https://youtu.be/fMfgU_X2Wxs


After I adjusted the #7 exhaust valve, no more clickety-clack for video #2. More timing and carb adjustment is needed.

https://youtu.be/y8MlNQl0htk

If you need a refresher, here is the Jasper 283.
https://youtu.be/VZvKYQmGzrY

Specifics of this 1965 283ci build.
KB Hypereutectic .060" Oversized Pistons
Hastings Moly Rings
USS Viton positive valve seals
Qualcast High Performance Valve Springs and Retainers
Federal Mogul .010" Undersize Rod Bearings
Federal Mogul .010" Main Bearings
Durabond Cam Bearings
Comp Cams 268 Lopey Idle Hydraulic Flat Tappet Camshaft
Cloyes Performance Timing Set
US Tool Brass Expansion Plugs
Victor Reinz Gaskets
SBI Valves
Melling Pushrods
Melling Oil Pump

[Warrens69GMC]

Are you running HEI modules in the point distributor, or just points?

[Lugnutz65]

Originally Posted by Warrens69GMC

Are you running HEI modules in the point distributor, or just points?

I plan to run Pertronix so I don’t have clearance issues with the dizzy cap at the firewall.

[Warrens69GMC]

Gotcha

[geezer#99]

I’d run one of these instead.
Once installed the module wouldn’t likely be seen.


https://performancedistributors.com/...nition-system/

Or this one.


https://performancedistributors.com/...ower-ignition/

[geezer#99]

What is the idle vacuum reading?
Motor sounds timing retarded.
What initial you gonna run?

[Lugnutz65]

Originally Posted by geezer#99

What is the idle vacuum reading?
Motor sounds timing retarded.
What initial you gonna run?

Right now I’m adjusting the carb. More adjusting is needed. At present it runs well at 850 RPMs and timing is 14 BTDC at 850. Manifold vacuum is just outside the green zone on my gauge, around 17 based on internet pictures of the gauge. I think it will be better now that I’ve properly adjusted the #7 exhaust rocker.

[geezer#99]

I’d turn the idle down to 600 and then set the timing and adjust the mix screws.
Lower idle eliminates any mechanical timing kicking in and closes the throttle raising the vacuum and making the mix screws more responsive.

[Lugnutz65]

My goal is to bring idle down to 600-750. I have not achieved that yet but will keep trying. We are on the same page.

[cwcarpenter98]

I like the sound of that one! I'm looking forward to seeing what it sounds like at idle after you have everything set the way you want it

[Lugnutz65]

Originally Posted by cwcarpenter98

I like the sound of that one! I'm looking forward to seeing what it sounds like at idle after you have everything set the way you want it

Getting close to having things set. The idle sounds really nice. Not sure the manifold vacuum is where it should be. Seems low but might just be the cam. I was surprised it would idle at 650 with only 9* of advance.
Here the video from tonight.

https://youtu.be/qcyXLX_5n78

[cwcarpenter98]

Originally Posted by Lugnutz65

Getting close to having things set. The idle sounds really nice. Not sure the manifold vacuum is where it should be. Seems low but might just be the cam. I was surprised it would idle at 650 with only 9* of advance.
Here the video from tonight.

The link says video unavailable. Got a different link?

[Lugnutz65]

Originally Posted by cwcarpenter98

The link says video unavailable. Got a different link?

Fixed the link. Sorry about that. Please edit you “quote” because it contains the deleted link. Thanks.

[cwcarpenter98]

Oh yeah, I like that a lot

Also, thank you for sharing your specs. I've got a 65 283 that's sitting in my parent's basement waiting on a refresh. That sound is giving me inspiration

[Lugnutz65]

I have the timing set at 9* of advance at 650 RPMS. When I hook up the vacuum line to the canister on the distributor, it bumps the idle up from 650 to 800 RPMS. I also get a stumble on quick acceleration as if my accelerator pump isn’t working. I’m wondering if I need stronger springs on the mechanical advance.
What do you suggest?
Remember, this engine has not been in a vehicle and has not been under any load so maybe that should happen first before I change things around.

Here’s the VIDEO. https://youtu.be/NqXd_rwuFQ4

[geezer#99]

Plug off your vac advance and bump your initial up until the hesitation is gone.
You should have no problems at 14 degrees initial.

[Lugnutz65]

Originally Posted by geezer#99

Plug off your vac advance and bump your initial up until the hesitation is gone.
You should have no problems at 14 degrees initial.

You saying I should KEEP the vacuum advance plugged permanently?
FYI, yesterday I had advance set at 20* and the stumble was gone but I detected issues at 3800 RPMs.
With it set at 9* the issues in the upper RPM range (3500-4600) are gone.

[geezer#99]

To avoid the stumble you likely need more initial.
More initial might mean a lowering of the mechanical timing and a limit on the vac advance.
I always leave the vac pot plugged off until all the carb and distributor mods are done.

[crazy longhorn]

I agree, you need to recurve the dizzy......I would look @ 12 to 14 intial, with a total around 34 @ 3000 (vac advance unhooked). The vac can is not part of the total advance,but a load compensator. If you pull anouther 10-12 degrees (crankshaft) on the vac advance, you should be in the ballpark. Do hook the vacumn advance to a manifold source. You may see 22-24 degrees @ idle with the vac can plugged in.....& more vacumn on your guage. If you buzz it up (no load on the engine), say 48-50 on the timing @ 3000 rpms. When you stomp the loud peddle, that vac advance will drop out leaving you back to that total timing around 34 @ 3000 rpms......best of both worlds Understand that the timing specs, are for a stock engine.....the camshaft is pretty healthy in that 283, & that will change the timing(curve) needs. Best of fun....Longhorn

[Lugnutz65]

I mixed 10 parts gray + 7 parts black SPI epoxy primer until I got a gray that looked correct for a 1965 283. I then added the appropriate amount of activator.
Exact match? Maybe not, but pretty close.
The timing cover and oil fill tube look darker but that’s because the cast iron has more surfaces to reflect light. (Kinda like a disco ball haha!)

Anyway, thought I’d post the pics.

[cadillac_al]

1965 283's were gray? Never knew that, and Chevy Orange is so pretty too. I plan to mix up some SPI gray and black for the undercarriage of my Camaro for a racy industrial look.

[Lugnutz65]

Here are pics of an original 1966 C10 283. It has the gray 283 that I’m trying to match.

[AcampoDave]

Originally Posted by cadillac_al

1965 283's were gray? Never knew that, and Chevy Orange is so pretty too. I plan to mix up some SPI gray and black for the undercarriage of my Camaro for a racy industrial look.

Until I joined this forum, I didn't either. I painted mine orange. But, since I was going for stock, I eventually decided to pull my motor and repaint it gray.
Motor looks great Lugz

[Ironangel]

What Geezer and Longhorn said...You need a bit more advance, 12 to 15 degrees with the vacuum advance port plugged and idle set at 600.

[67C10Step]

Super and fantastic! I am still running the original 283 in my 67 and wonder down the road if I’ll refresh it or swap it out. I swapped mine to HEI with no issues. Right now I have my timing set at 12 degrees initial and 32-33 at 3000-3100 rpm. I’ve only just got my truck on the road and it runs pretty well. Idle seems a bit high and checked it with my timing light and it was 800 rpm. Thinking I’ll lower that to 700 and double check all my timing.