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Covalt - "Project 65 Valiant"
https://slantsix.org/forum/viewtopic.php?t=35632		 Page 123 of 124
Author:  Rick Covalt [ Tue Dec 31, 2024 3:50 pm ]
Post subject:  Re: Covalt - "Project 65 Valiant"
The other reason I don't expect much if anything wrong is that with the Webers there is no hook up for a PCV valve. So any blow by would be coming right out the valve cover, and I have none.
Quote:
if I can't hear compression squirting into the pan it's good to go.
I have that too!
Author:  Dart270 [ Wed Jan 01, 2025 1:07 pm ]
Post subject:  Re: Covalt - "Project 65 Valiant"
Something seems funny with your overlap number. Please post the lobe separation angle (LSA) for both cams and the installed centerline. Gotta be the cam. 11:1 static CR?

Bigger cam will give you less cranking compression. Yep, I would race that thing on pump premium, assuming I have the max advance dialed in at 28-30 deg total.

Lou
Author:  Rick Covalt [ Thu Jan 02, 2025 4:48 pm ]
Post subject:  Re: Covalt - "Project 65 Valiant"
Here are the two cams. Durations and overlap are at .050, Engine is 11.5 to 1 static compression

I plugged the cams into a calculator and found the Dynamic Comp. on the original cam was 8.98 to 1, current cam is 8.61 to1.


Original Cam---.566/.566--257/257--104LSA--102ICL--Installed-@100--49 degrees overlap---@185# comp.
Current Cam---.571/.550--267/262--106LSA--102ICL--Installed-@100--52.5 degrees overlap-@ 155# comp.

I did go out in the garage today and warmed up the engine for a while. I did a retest on cylinders 1 & 2 for leakdown and both were about 8%. I figured all the others were going to be about the same and it was hard holding the engine from turning and hooking up the tester at the same time.
Author:  Rick Covalt [ Fri Jan 03, 2025 5:11 pm ]
Post subject:  Re: Covalt - "Project 65 Valiant"
While I was out warming up the engine I thought I could here a funny valve ticking. When I pushed on the top of the valve cover I could make it worse. Just like Greg's engine, when I pulled the valve cover I could see 4 places where my adjusting studs were just barely tipping the underside of the valve cover. So I cleaned everything up and I will just install the new spacer I got from Matt. Want to make 2 of those fancy valve covers Greg? :D :D
Author:  slantzilla [ Fri Jan 03, 2025 10:17 pm ]
Post subject:  Re: Covalt - "Project 65 Valiant"
Let me know what you think of the spacer. I have one too, it looks pretty good. :mrgreen:
Author:  Rick Covalt [ Sat Jan 04, 2025 8:56 am ]
Post subject:  Re: Covalt - "Project 65 Valiant"
I ordered some studs to put in the head for the valve cover. I also took a brand new gasket and glued it permanently to the spacer bottom side. Snugged it down in place on the head and left it set up. That should eliminate one place to leak. A new rubber gasket on the top side and I'll give that a try. The spacer looks great and lines up well. :D :D
Author:  Dart270 [ Sat Jan 04, 2025 12:56 pm ]
Post subject:  Re: Covalt - "Project 65 Valiant"
Rick,

Thanks for the numbers. Still need to plug those into my cam spreadsheet to check overlap number.

The only other thing might be valve lash. i assume you are lashing both cams at similar specs. Depending on the cam (long vs. short ramps, I assume), and the lash you use, the cranking psi can be way different. I added about 0.006-0.010" to the lash that Seymour was using on the Racer Brown cam in the white 62 and it picked up at least 10-20 cranking psi, but I can't recall how much. Changed the behavior completely on the street, and didn't seem to lose any higher end HP...

What lash are you using on int/exh?

Lou
Author:  Rick Covalt [ Sat Jan 04, 2025 4:52 pm ]
Post subject:  Re: Covalt - "Project 65 Valiant"
I generally don't mess with the valve lash much at all. Whatever Oregon Cams puts on the cam sheets I use. :D :D

Current cam with lower compression is .024 on both valves and I just did adjust them last week. The old cam with the higher compression numbers was .026 on both valves.
Author:  Dart270 [ Sun Jan 05, 2025 5:24 am ]
Post subject:  Re: Covalt - "Project 65 Valiant"
Good to know, Rick. My rule of thumb is that whatever the cam maker stated for valve lash is always wrong. You can always do better. MP is the only outfit that I think got close to optimizing their valve lash, probably with Racer Brown's help/designs?

If you feel like doing an experiment, you could lash the valves at 0.032" on both int and exh and then re-measure your cranking comp. It won't matter much as long as you are getting the idle quality and performance you want, but it would be fun to know. The cranking psi can be heavily influenced by lash setting, but the overall cyl pressure at high RPM will not care much about lash. Once you hit a valve lash that maxes out your cranking psi, you can open the lash more and it won't affect the cranking psi much. In other words, there will be a threshold...

Lou
Author:  Rick Covalt [ Sun Jan 05, 2025 10:35 am ]
Post subject:  Re: Covalt - "Project 65 Valiant"
I still have the valve cover off. So I could give it a try and see if it changes it much! Thanks Lou! Hope your healing up some! Take care.
Author:  Rick Covalt [ Mon Jan 06, 2025 3:48 pm ]
Post subject:  Re: Covalt - "Project 65 Valiant"
Ok, I pulled all the plugs again and adjusted the #1 cylinder valves to .032. This was all done cold since I still just have the valve cover setting there. I wasn't going to run it till hot just for this "test" However I am pleased to say that I had @ 172# compression on #1. That is 21 more pounds than I had at .026 setting! :D :D That is pretty amazing to me. And I certainly don't understand it!! :D :D Maybe Lou will learn me! I am guessing that adjusting all cylinders to .032 should help performance? Thanks for the info Lou! 12.60 here I come!!! :mrgreen:
Author:  slantzilla [ Mon Jan 06, 2025 4:03 pm ]
Post subject:  Re: Covalt - "Project 65 Valiant"
If you open the lash up and go faster, you have too much cam. :mrgreen:
Author:  Rick Covalt [ Mon Jan 06, 2025 5:14 pm ]
Post subject:  Re: Covalt - "Project 65 Valiant"
I be so confused :D :D
Author:  slantzilla [ Mon Jan 06, 2025 7:39 pm ]
Post subject:  Re: Covalt - "Project 65 Valiant"
At least your car isn't slow. :mrgreen:
Author:  Rick Covalt [ Tue Jan 07, 2025 2:42 pm ]
Post subject:  Re: Covalt - "Project 65 Valiant"
I am assuming that it would be fine to run .032 on the valves?
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