1983 470 170hp hardened exhaust seats

[fmalott]

as per my other thread i understand this hardening process now, i was talking to the three mechanics were i do my work and i ask them about this process and they explained why they did it but one mechanic said that if it's a 1983 motor that the head should be already done is this true for this 470 head because after 1980 or 81 they stopped the lead additive and hardened because of this will i see this when i pull the head off

 

[dollarten]

Re: 1983 470 170hp hardened exhaust seats

as per my other thread i understand this hardening process now, i was talking to the three mechanics were i do my work and i ask them about this process and they explained why they did it but one mechanic said that if it's a 1983 motor that the head should be already done is this true for this 470 head because after 1980 or 81 they stopped the lead additive and hardened because of this will i see this when i pull the head off

One person on the previous thread talked about the hardening process on the original cast iron head (s) that were going to be run on unleaded fuel . Allow me to explain this further on the matter The factorys used what was called an induction hardness that was applied to the valve seat area only . I was a heat treat process of sorts and was not very deep into the seat area .This process was stated in the mid 70's when leaded gas was fazed out Some people have told me that when you regrind the valve seat you will grind through this area and will be back to the original cast iron material that the rest of the head is made of . The hardening is not very deep . This is just my opinion and others are free to have others . When the valve spring seat pressure is 100 pounds( closed) or lower , I feel the need to have hardend seats installed is uneeded. Higher performance engines where higher spring pressures are needed due to more aggresive camshaft profile could call for hardened seats along with a debate on how the engine will be run to be the final determining factor .

 

[fmalott]

Re: 1983 470 170hp hardened exhaust seats

by what you said probaly the head is not done ?

 

[joewithaboat]

Re: 1983 470 170hp hardened exhaust seats

What dollarten said is VERY accurate by my experience. I worked in a machine shop for 2 years in college. Shop owner is a good freind to this day. We saw MOST problems when people were running higher than normal spring pressures.

Your head would have been Induction hardened. Some are deeper than others. An attentive person can tell when rehabing a head if one seat is softer than others whithin the same head. They grind at a different rate and sound different.

Shops will also put seats in to be able to re establish the proper installed height especially on motors with non adjustable valve train.

As a side... ford vs. Chevy... In my own personal builds this seems to be much more of a problem in fords. Maybe GM did a better job with the hardening ??? A point of view of a friend is that ford stock rotators spin the valve more, which speeds up seat erosion, he runs Chevy style retainers on ford heads that don?t have hard seats.
You will also find a lot of people that think the whole thing is "bunk" and that lead had nothing to do with it... To each there own.

 

[fmalott]

Re: 1983 470 170hp hardened exhaust seats

ok i think i'm getting the picture well i will definitly be talking to the machinist about this before any work gets done