I have a 98 Vette with them factory crappy *** 806's, lol, and I bought a set of BARE 243's. Well I want to swap the valves from my 806's, as far as I know, they have the same size? Or not? Someone on a different forum said the valve length is different between the two...??

 

I THINK, I swapped valves from 853s (could have been 806s) from my 1997 vette to 243s.

Never even thought about it. Doesn't smoke or use oil. Didn't hit the piston.

Maybe I didn't swap the valves, I know I swapped the springs from yellow to dual springs...

I'm no help, sorry.

 

806 and 243 use the same valve diameter 2.00I 1.55E
The valve lengths are different.
ls6 243s use a longer hollow stem intake and hollow stem sodium filled exhaust

LS6 valves are 0.6mm or 0.023622

 

Lol

So you mean the 243's have about .023" longer valves? So does this mean the tips of the valve stems are sitting .023" taller from the deck? Or is the whole valve sitting lower in the head giving it the same deck to valve stem height as any other LS1 head?
Also, if the valve is sitting lower in the the head, and I were to use my shorter 806 head valves, I would just need a longer pushrod? If this is the case, I could run the stock pushrod length, because my 243's are milled .030". Correct?

 

Obviously then my valves must have come in the 243s I bought. However mine were not off a Z06, so the valves were not sodium filled.

 

As far as I know the only 243 valves with different lengths are the true ZO6 243s with sodium valves. The regular 243s have normal valve and are normal length. I would double check valve diameter to ensure they are the same though.

 

why not use NEW Valves ?

 

I might have a Corvette, but that doesn't mean I have money hanging out of my pockets... The C5's are much more affordable now, I only have $10k wrapped up in mine, it retails for $15,800...

 

Do a Google search for Hib Halverson's article, "The ruthless persuit of power- the sequel". It tells you all you ever wanted to know about the '02-'04 Z06 heads.
To summarize:
The '01 Z06 had the 243 heads, but used standard valves.
In '02 they increased the lift to .550, and had to reduce the cam's base circle from 19.7mm to 19.0mm.
They had to make up the slack somewhere, to keep the lifter preload in a good position.
They could have used longer pushrods, but were concerned with mixing them up with the std parts on the assembly line.
So instead, they lengthened the tips of the new-for-'02 hollow valves by 0.6mm.

So, basically, std valves will bolt right in the 243 heads (they are used in the lS2 engine, which has 243 heads). IF you use a std LS1 cam, no mods are required. BUT, IF you use an '02-'04 Z06 cam, or many of the aftermarket hi-lift cams, then you will need to use longer pushrods to offset the smaller base circles on these cams.
If you already have an aftermarket cam, and have set it up with your stock heads, then switching your stock valves to the bare 243's will require no other mods.

But, it's always a good idea to do a pushrod length/lifter preload/ rocker-arm wipe check whenever replacing any valvetrain-related components. Who knows, the new heads may have been previously milld, or your new gasket may be a different thickness.

Search herein for al the gory details on selecting the correct pushrods.

DG

 

Still believe with new heads, new valves, new springs, new rockers are must have.

Putting old or used valve train in new heads, might be better to leave everything alone.

 

Thanks for that info, The Wrench, that was exactly what I wanted to know.

 

The heads are used, if they were new I would put new valves in. Springs are always a good part to replace because they start to weaken over time, especially if you have a big cam and stiff springs. But rockers? The rockers on the LS engines are damn near bullet proof... My brother has an LS1 with rockers that have almost 200k on them, 60 or so thousand of which it had an aggressive cam and dual rate springs, and there's countless other people who have done the same or more without failure. Mabe not on this site but if you spend time on ls1tech or performancetrucks, you'll see what I'm talking about. I'm not to worried about the rockers. But thanks for wachin out for a fellow Vette owner

 

been on ls1tech quite a bit. Think there is a weeee bit stretching of engine reliability over there too.