SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: Luckie Stiff on January 04, 2010, 04:05:14 PM

Title: Valve lash clearance?
Post by: Luckie Stiff on January 04, 2010, 04:05:14 PM
Here's how I do mine. Can anyone give me a reason not to do it this way? I also set mine cold I add .002 to the final number to allow for expansion, again any reason not to do it this way?
Finally, what lash do y'all recommend? No, I don't have my cam card or specs so I'm looking for a generic setting.

Thanks
Skip

SOLID LIFTER CAMSHAFTS

Once again, the most important part is to remember to adjust just one valve on one cylinder at a time – starting with #1 and working your way through the firing order. To begin, check the spec card that came with your cam for the correct valve lash specifications.

Proper adjusment of the # 1 exhaust valve.


Rotate the crankshaft by hand until the exhaust valve begins to open on the #1 cylinder, adjust the intake valve by loosening the adjusting nut slightly until you feel lash on the rocker arm. Now you can set the lash on the intake valve. Spin the intake rocker nut down with the correct thickness feeler gauge inserted between the valve stem and the tip of the rocker arm. Tighten the adjusting nut until there’s a slight drag when moving the feeler gauge. After setting the lash on the #1 cylinder intake valve, put a magic marker across the top of the rocker to assure yourself it has been adjusted. Following this procedure, carefully adjust all intake valves.

To adjust the exhaust valve, rotate the crankshaft until the intake pushrod opens the valve all the way on the #1 cylinder and then begins to close (about ½ the way back down). With the correct feeler gauge, adjust the exhaust rocker nut using the same procedure as with the intake rocker above. Repeat for each cylinder, marking each rocker arm once it has been adjusted.

After setting your valve lash with the engine cold, it’s time to start it up and break it in to achieve normal operating temperatures. Due to thermal expansion, your valve lash should be tighter. Repeat the entire adjustment process to ensure your valve lash matches camshaft specifications, once again marking the rocker arm that have been adjusted. When finished, the rocker arms should all have an “X” mark on them – one mark for the first adjustment, another for the second.

I believe I'm currently setting them COLD at .022 Intake .024 Exhaust
Title: Re: Valve lash clearance?
Post by: pw_Tony on January 04, 2010, 04:40:42 PM
Is it a Comp Cams solid cam? For a BBC?
Title: Re: Valve lash clearance?
Post by: beerjet on January 04, 2010, 04:41:42 PM
Set them all at 26 and you should be fine .
At least with the older cams .
I've set them other ways (easier anyways)
Double checked and was ok .

-beerjet-
Title: Re: Valve lash clearance?
Post by: Luckie Stiff on January 04, 2010, 04:57:02 PM
Quote from: pw_Tony on January 04, 2010, 04:40:42 PM
Is it a Comp Cams solid cam? For a BBC?

It's a solid cam, BBC, unsure of make & grind
Title: Re: Valve lash clearance?
Post by: pw_Tony on January 04, 2010, 05:04:01 PM
Quote from: beerjet on January 04, 2010, 04:41:42 PM
Set them all at 26 and you should be fine .
At least with the older cams .
I've set them other ways (easier anyways)
Double checked and was ok .

-beerjet-

+1, .022 might be too tight for a chevy. My Comp Cams lash requires .028
Title: Re: Valve lash clearance?
Post by: Ralph Brunt on January 04, 2010, 05:28:14 PM
here ya go ;)
(https://www.socaljetboats.com/cpg/albums/userpics/10041/valvelash.jpg)







oh my bad :P its for a chebby not a ford ;D
Title: Re: Valve lash clearance?
Post by: enginedoctor on January 04, 2010, 05:45:58 PM
Ooops Ralph ;D
Title: Re: Valve lash clearance?
Post by: beerjet on January 04, 2010, 09:29:05 PM
Quote from: pw_Tony on January 04, 2010, 05:04:01 PM
+1, .022 might be too tight for a chevy. My Comp Cams lash requires .028
After dealing with my motor and not knowing ANYTHING about the cam, eveyone told me to set it 26.
After digging through several books , they all said 26.
I finally pulled the cam out and called clay smith and they said 26 (I think :sly:)
I ran mine at 22 and gained nothing.
24-26 was the best set up.
I would go at least 26

-beerjet-
Title: Re: Valve lash clearance?
Post by: GT Jets on January 04, 2010, 09:39:12 PM
I'm of the thinking that .026-.028 cold should be good, square (same intake as exhaust) the motor will be running cold enough to assume you will not have the exhaust valve growth of a car app.

What rockers are you running?  Factory ratios?

My uncle always said it comes into play if extreme, it came up when I was doinking around with an engine that had different ratios from intake to exhaust....Don't ask....But it's still that way and still is a running focker....(made up for some cylinder head oversights....)


I have not forgot about the oil, still waiting for an update from you know who  :banghead:.

GT
Title: Re: Valve lash clearance?
Post by: Luckie Stiff on January 04, 2010, 09:44:55 PM
GT-

Roller Rockers, 1.7:1 ratio.  In talking with Jim Brock I'm going to set them @ .024 cold, both intake and exhaust. He seems to recall that's where they were when Towbama bought the boat.

Title: Re: Valve lash clearance?
Post by: GT Jets on January 04, 2010, 10:09:05 PM
Quote from: Luckie Stiff on January 04, 2010, 09:44:55 PM
GT-

Roller Rockers, 1.7:1 ratio.  In talking with Jim Brock I'm going to set them @ .024 cold, both intake and exhaust. He seems to recall that's where they were when Towbama bought the boat.



Lash equates to "valve to seat time" in degrees, with roller rockers and .024" lash, I think you will be GTG, if they were stamped steel dealios, .026" min....just my .02

The rollers give a "softer" actuation of the valve and should equate to more time to keep things cool..The last thing you want to do is take a piece of pie out of a valve.. :thumbup:

You get good information seeing failures on the marathon motors because they virtually run for 40 min. to an hour at WFO and if that isn't a good test of what works and what don't, then I'm screwed... ;D

Just an observation, nothing to see here.. ;)

GT
Title: Re: Valve lash clearance?
Post by: IRRebel on January 04, 2010, 10:12:33 PM
If I remember right, I think mine were set originally at .026, then I readjusted them last Fall before AVI at .026.........Where the hell did I put that sheet?....... :screwy: I think it said to do it hot at .024, but not really practical on a jet boat. So I just added .002 to what the specs said and set them cold. I'd be really surprised if the valvetrain expands enough to overcome the .002"  in a jet boat.

That's a Solid Comp Cams with roller rockers on a BBF though. Does rattle and clack a bit when cold, but a lot of that is the forged pistons. Once warm, at full speed, you can hear a slight, but persistent, "buzz" from them, so mine are probably a tad loose.

I think you're in the ballpark +/- .001 though. I wouldn't sweat it. I might play around with tightening them down a tad to .024 or more to see if some of the buzzing goes away this summer. This is STILL a work in progress, didn't know that many of you were also running solids!

Ray
Title: Re: Valve lash clearance?
Post by: GT Jets on January 04, 2010, 10:18:20 PM
Quote from: IRRebel on January 04, 2010, 10:12:33 PM
If I remember right, I think mine were set originally at .026, then I readjusted them last Fall before AVI at .026.........Where the hell did I put that sheet?....... :screwy: I think it said to do it hot at .024, but not really practical on a jet boat. So I just added .002 to what the specs said and set them cold. I'd be really surprised if the valvetrain expands enough to overcome the .002"  in a jet boat.

That's a Solid Comp Cams with roller rockers on a BBF though. Does rattle and clack a bit when cold, but a lot of that is the forged pistons. Once warm, at full speed, you can hear a slight, but persistent, "buzz" from them, so mine are probably a tad loose.

I think you're in the ballpark +/- .001 though. I wouldn't sweat it. I might play around with tightening them down a tad to .024 or more to see if some of the buzzing goes away this summer. This is STILL a work in progress, didn't know that many of you were also running solids!

Ray

Just bear in mind, a quiet solid is a doomed solid... ;)
Personally, I like the buzzing of a solid cam, add to it headers w/ Shotguns rattling around and a Jesel belt drive, we're talking sweet music you can't find for an Ipod..... 8)

GT
Title: Re: Valve lash clearance?
Post by: IRRebel on January 04, 2010, 10:28:29 PM
What the hell are the shotguns needed for? I'm amazed my half deaf ass can even hear the buzzing on the open headers Glenn!  ;)

Ray

But Yeah, too tight, wipe a cam (Or more) REAL quick!
Title: Re: Valve lash clearance?
Post by: GT Jets on January 04, 2010, 10:43:02 PM
Quote from: IRRebel on January 04, 2010, 10:28:29 PM
What the hell are the shotguns needed for? I'm amazed my half deaf ass can even hear the buzzing on the open headers Glenn!  ;)

Ray

But Yeah, too tight, wipe a cam (Or more) REAL quick!


LOL, If you run on a river classified as a Marine Sanctuary, the Shotguns keep you under 98 db and keeps time to be added to your run by the rulebook...

Sometimes going slower makes you faster. ;)

Besides, they look really cool, for mufflers anyways.  :screwy:

[attachimg=#]

 
Title: Re: Valve lash clearance?
Post by: IRRebel on January 04, 2010, 10:54:23 PM
Great! More linkages to set up properly.......as if I didn't have enough...... But those look cool as hell tho!  ;)  :thumbup:

Ray
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