Stock 409 Valves

[gearhead409]

at the convention Lamar Walden made a statement that there can be failures with using stock valves. i have some 409s with stock valves. this has me concerned as others in my area that we may break a head and/or block if we continue to run these valves. please comment. thanks

 

[Fathead Racing]

Valves?

For the price of a high performance head, replacing the valves with a quality stainless steel piece is a bargain. With todays fuel running with SS valves is a must anyway! When you have the heads off you can open the ports up a little too!I would heed this advice.

 

[Mr Goodwrench]

I'm with you on eveything you say fatride (love your 60 also) but the valves have never been the problem with th no lead fuel, always the soft cast iron seats in the head. we used to put hundreds of hardened seats in old heads every year beacause the seat eroded away and the valve sunk like the titanic. (just the exahst though) got one pair of heads in one time customer drove so long wore a hole through the rocker arm and the valve stem went through it!!!!

 

[gearhead409]

fatride

my problem is the engines i'am talking about are in new condition. one has 13,000 miles on it 425 hp, one has 5000 miles on it 425 hp, and my 481 blower motor has about 6000 miles on it. they were all built about 15 years ago. my buddy's 474 has about 10,000 miles on it and he races it. they are all using stock valves.sure hate tearing these engines back down. i am using ss valves in the engines i'am working on now but back when these engines were built we didn't. we sure have been loosing alot of sleep thinking about lamar's statements!

 

[Mr Goodwrench]

cheap insurance for some pretty expensive iron. I feel for you though tearing them back down.

 

[gearhead409]

MrGoodwrench

i've had alot of small block chevys in the shop with the two center exhaust valves reseated up in the head so far you'd wonder what kept the valve spring on. mostly truck engines.this also will damage the rocker arm and cam. one thing i noticed with customer hot rod engines i have built and mine too even without hardend seats when i adjust the valves at tune-up time they don't seam to be wearing the seats. point is our engines don't run lean and don't pull hard for long periods of time.

 

[Mr Goodwrench]

never did seem to be a rime or reason why, and it was only a concern on pre 1974-5 engines and at that some worse than others. heavy duty use did play a big part in it, but we used to get 289 fords out of gramdmas station wagon that did it, as well as other brands. point I was trying to make it has nothing to do with the valve as long as it's steel (did a 1910 model t once had cast iron valves in it) the problem when there is one is in the seats not being hardenend. after about 1975 except for a rare occasion it it was a non issue. another thing I'm not sure about is the lead content in racinig fuel cam-2or vp thought there was lead in it but not sure. might explaun why your seats dont seem to be wearing gearhead if you running this kind of fuel.

 

[Fathead Racing]

The thing is-

With the cast iron in these old heads when you cut new seats they are as hard as the hubs of hell! With the old valve there could be a transfer of metal from the valve to seat if the engine is under extreme load! SS valves prevent this. I think stainless valves are a good idea.

 

[gearhead409]

MrGoodwrench - Fatride

cam-2? the tee-bucket has a full tank of it right now and jimmy stevens uses it in his 474 when he races it. street driving we have been mixing it with unleaded. i think ss valves without hard seats would work ok with our type driving. now if you were planning to put a 100,000 miles on the old 409, you might need hard seats.

 

[SS425HP]

seats

Now I have to ask a question. I've heard for years that 409 heads can't have hardened seats put in, because they hit the water jacket when cutting the heads for the seat inserts. Is this true, or not? Curt Harvey has told me on several occasions to not try this. I have heard there is a seat available that is thinner, not requiring as deep a cut. True???????? I would like to hear from someone who has done this succesfully.

Fred

 

[mpris]

Fred, when I had my heads done in 2002, Chevy Rumble did an article on the machine work for the heads. I believe it is in the August/Sept. issue. I have attached two of the pages from the article which talked about the seat work. Hope this helps. I had to attach the text seperately because the picture was so large and I had to reduce it the text became unreadable.

Poocho

 

[Mr.Jimmy]

There is a special design of a seat that is suppose to work better than the std. elgin ones. The std elgin ones take up more space, thus, requiring more meat to be taken out and then having the risk of hitting water. There was some info somewhere that was writtng by or for Tony that explained this.

 

[Bungy]

While we're on the subject of valves, I have a question. I found two sets of stainless for sale and one was 21-2N and the other was 21-4N. What's the difference? Is one better then the other?

 

[gearhead409]

Fred

using a std. hard seat insert you may hit water. this is a little risky considering the price of 690-583 heads. there is a insert available that is only .250 long these will work. but again lamar has said these may not stay in place under hard use. the last 09 heads i had seats put in was so bad we did intake and exhaust seats. after talking to tony shaffer at the convention, it would have been better to put larger valves in to make the repair.
this was done about five years ago on a customer's motor and it's still running.

 

[Mr Goodwrench]

most seats we put in were only 7/32" thick and were put in + .020 deep. a blunt punch was used to roll that .020 over the seat, along with red loctite we NEVER lost one. some of the hi-po valve jobs I see now using many angles to countoure the seat may actually prevent you from doing this though. regardless I would always recommend installing new valves, steel for stock usage would be fine with me SS for heavy duty, or Hi-Po use. Hell the SS ones are prob more inexpensive than the steel ones for these engines, and easier to get, so might as well just go with the best the first time arround.

 

[Skip FIx]

Most stock or stock replacement valves are two piece. Alot of spring pressure(especially rollers) can pull off the head in worse case scenario. Most SS valves are one piece so they won't separate with higher pressures.

 

[gearhead409]

Skip Flx

so what would you think the chances of this happening to a stock solid lifter 409 with it's 320lb valve spring pressure?

 

[dq409]

so what would you think the chances of this happening to a stock solid lifter 409 with it's 320lb valve spring pressure?

Ahhhhh Vegas style betting !!!

How old are they? how hard were they run before? metal fatigue?
Unanswerable,,,,,

Pulling the heads now and changing valves now verses later after one breaks?,,dq

 

[gearhead409]

Thanks

after reading all your replies i think jimmy and i will be doing alot of head work this summer! PS. jimmy bought another 63 belair last week, i smell another stroker coming on this summer. ss valves in this one? you bet.

 

[Skip FIx]

I've got a set of GM stock valves I'm probably not going to use for that reason when mine goes together. Some of my Pontiac buddies have experienced this. So a one piece is definitely an insurance for these motors.