333 heads questions, again.

[heddrik]

Machine shop valve man says no cracks but all my valve seats are completely shot. I am putting in 2.09/1.72 valves, wont that nullify use of seats with SS valves? I know some will not put hardened seats in 333 heads with over sized valves, how much risk is there in that? i wasn't aware these heads had hardened seats on intakes anyway. As always, your comments, suggestions and opinions are very much appreciated. Seems like every time I start I go back 3 steps. I will buy valves this week. Thank you.

 

[La Hot Rods]

Generally the harden seats go on the exhaust side the intake can be opened up for a larger valve seat in the head casting. If you use SS exhaust valves you can seat to the cast head depending on how hard you plan on using this engine.

 

[427John]

Heddrik these heads did not have seat inserts from the factory,unless they have had inserts installed at some point in the past or have damage where he would need to cut the new seats as my heads did,it should be a matter of cutting the new seats.Cylinder head machine shops really push installing hardened exhaust seats due to unleaded gas,but w heads are not as thick as other engines in this area so your better off not installing seats if not absolutely necessary,if it is necessary make sure the machinist is aware to use shallow seats to minimize how deep they have to bore for the seat insert to make sure they don't cut into the water jacket.My heads had some pitting where the new exhaust seats needed to be so I had to have hardened inserts installed.As La said if you're using stainless valves there is no reason you have to use hardened inserts.

 

[heddrik]

Thank you, those were my thoughts as well, just checking to be sure.

 

[heddrik]

John, what size valves did you put in your 333's? I wasn't aware of thinner seats either. thank you.

 

[64ss409]

When I rebuilt my 09 in about 2004, the heads had bad exhaust seat recession. He recommended hard seats. I asked the machinist if the 409 heads were too thin? His reply, All Chevy heads are thin. Don't worry about them. They have been OK.

 

[heddrik]

Thank you 64SS409. What heads (690, 333, etc.) and valve sizes did the machinist use ?

 

[64ss409]

817's Stock valves back in.

 

[Tim]

Ok so I’ll chime in, for my 817 heads as long as I use stainless valves(which are lost in USPS) I don’t need seats?? Or if I do the non hardened ones?? I may need them because from what I see there was already a 3 angle valve job done at least once.

 

[Ishiftem]

You don’t need seats unless yours are pounded out.

 

[heddrik]

You don’t need seats unless yours are pounded out.

Pounded out? means what exactly? worn completely out I assume? Thanks for responding Ishiftem

 

[Tim]

Dan, They don’t look bad. All about the same. They may have to tweak them some but not pounded out with rolled edges. Just didn’t know the criteria for seats.

 

[Don Jacks]

I think that they'll be fine.Nice bowl work from what I can see.

 

[La Hot Rods]

That looks like it has a seat installed on the exhaust side from here.

 

[427John]

I've had 2.06/1.72 and 2.19/1.72 installed in 333's with no complaints from the machinist.He was the one that told me about the shallow seats.

 

[Tim]

That looks like it has a seat installed on the exhaust side from here.

I’ll have a closer look James but when I did the bowl work there was no seam.

 

[buildit]

I once bought a core 409 truck engine up in Montana. The #2 exhaust valve had receded so far that it got into water.

 

[427John]

That means it was used as intended well after the time leaded regular gas was no longer available and I remember still being able to find it clear up into the late 80's-early 90's.

 

[dakota tom]

Propane use will cause valve seat wear also.

 

[heddrik]

Thanks Tom, I was not aware of that. I will probably add lead to my gas to help extend valve life.