marshall93z

I guess that's because you like to see it centered. I chose 7.200, which are the ones that were in it on the first page. I can't think of a reason why the pushrod length was responsible for your guideplate damage??

Colin91Z

How do you figure that you lost lift and duration by going to a shorter pushrod? Thats like saying you gained displacement by switching to longer rods with the same crank

You lost nothing as far as lift and duration by switching to the proper length pushrod

wrd1972

When I created post inquiring about the problem everyone said PR's are too long, I was told to check my geometry. I did it the way they said and 7.050" solved the wear issue.

I was told this by some other guys in this thread as well as in some of the links I attached above.

Colin91Z

Well they told you wrong. The only way that you could possibly lose any lift and duration from a shorter pushrod is if you rocker arms were not adjustable. But they are, so that solves that.

marshall93z

You lose lift with the wrong PR because the rocker is moving ACROSS the valve stem instead of pushing it down. That's why you want the narrowest sweep you can get.

You want it pushing down as much as you can.

Colin91Z

Ahhh...I see what your sayin Whatever you lose from that can't be much at all though. It probably cost more horsepower from the added friction than it does from loss of that tiny amount of lift and duration.

marshall93z

Exactly! Just another reason to have it right.

Colin91Z

Yes sir, I agree

And mine IS right...7k shiftpoints with BRE's (or should I say comp's) aggressive lobes on 918s here it slows down if I shift at anything less than 7k, so I'm pretty confident that I'm not floating any valves So far so good anyways, but I keep a close eye on everything because of how aggressive the lobes are...

blue 79 Z/28

this is off advanced inductions website in their cam section with cross referencing their grinds to other manufacturers.

http://www.advancedinduction.com/AiProductsCK.html

Comp 224 / 230 HL - .605/.598 - 107 LSA CompCams Lobe #'s - Intake: 3192 Exhaust: 3111
In recent years, some self-proclaimed "valvetrain gurus" online have aggressively marketed cams utilizing lobes from one of Comp's most aggressive lines - the "3100" Xtreme Energy Series. While they will typically run well initially, the irresponsibly aggressive lobes tend to quickly fatigue even the new ovate beehive springs in only a few thousand miles. As the spring loses both load and rate loss of valvetrain stability occurs lower and lower in the RPM range. Typical symptoms are loss of power & "missing" above 6000rpm. Left unaddressed, this ultimately leads to spring failure or piston to valve contact. For comparable output without sacrificing longevity, we would recommend either our 226/234 or 230/238 grinds.

wrd1972

How ironic that I follow up Blue's reply with a status on my PAC1218 beehives that are causing my valve float.

Just pulled both beehives off of #1 cylinder. Seat pressure is 115@1.775 and 120@1.750 for the intake valve. Seat pressure is 130@1.775 and 135@1.750 for the exhaust. The springs have less than 2K miles and are junk just like blue said.

Also just found out that the Comp 921 dual springs will not fit the LT1 heads without machining the guides to .500".

Wont be racing this weekend.

Looks like I need the LT1 Patriot dual spring kit. Anyone have a part number for this and where do I get them?

speed_demon24

The patriots won't work without machining the guides either. I was going to put a set back on when I was running that cam. It looks like you are going to have to change your springs twice every oil change.

FWIW my 918's lost 15-30 lbs of pressure in 4k miles.

wrd1972

Llyod Elliot said the Patriots would work and they are listed as working for SBC on their site. I hope your wrong. Guides measure .556. Site say seats ID is .565". I think your wrong. Someone confirm this ASAP.
https://www.patriot-performance.com/...&cat=52&page=2


New springs every oil change. Thats not kewl man.

speed_demon24

I bought them, first they sent me an LS1 kit, so then they sent me the LT1 hardware. Their seals didn't even come close to fitting, their OD was about the same as the ID as my guides. So I bought some fel-pro seals from the parts store that I always used in the past and they didn't even come close to fitting inside the inner spring. I was also in touch with someone else at the same time who bought some for his LT1 and he had to machine his guides down. All of the hardware fit fine it's the seals that didn't fit. They did give me a refund so it wasn't a total waste. And if your cam ate up pac springs that quick I would think they would do the same with the patriots.

speed_demon24

JFYI the 921's and patriots are the same dimensionally IIRC so if one won't work neither will the other.

wrd1972

I will call Patriot tomorrow, this makes no sense. According to their sight the set should fit properly. SBC guides are ~.556 and they claim the ID on the seats are .010" bigger. SBC seals are ~.556 or so. Even the site says "No cutting or machining of the stock spring pocket is needed." Could they have sent you more of the wrong stuff.


Lloyd told me he had used them.