Inlet Valve seat inserts for the Pinto head

**hawk1903** · 31-01-2021, 08:44

Dear Friends,

Do you have any experience with the valve seat inserts on the inlet side?
Have you ever come across or used valve seat inserts on the inlet side ?

Normally ( or may be ideally ) Pinto doesn’t require seat inserts on the inlet side since the cast iron which is also the part of the seat should be good enough for using larger than standard valves etc but I suspect the seat area on the standard head may be induction hardened ( may be not - I don’t know ).

But if it is hardened from the factory once the seats are machined for larger valves then the hardening may go away/lost. And knowing the fact that most aftermarket 21-4N valves are harder than the OE valves so wouldn’t it be the case that machined seats ( without inserts ) may suffer from the hard valves and high spring poundage etc ?

Last but not least, copper/bronze seat materials are not good for heat conductivity when they are used in the cast iron heads. So what could be a good seat material if possible to use on the inlet side ?

Regards
kerem

**Graham** · 31-01-2021, 09:38

inlet seat are not induction hardened, and the head doesnt need inlet inserts .with full race cams/engines. in reality there isnt room for both inlet and exhaust inserts anyway

**hawk1903** · 31-01-2021, 09:50

Originally Posted by Graham

inlet seat are not induction hardened, and the head doesnt need inlet inserts .with full race cams/engines. in reality there isnt room for both inlet and exhaust inserts anyway

Hi Graham,
Thank you very much. Then since we have to use inserts on the exhaust for unleaded, we don’t have a chance to use inlet inserts.
So once the inlet seat has sunken and beyond further cutting limits, the head is basically scrap.
What material ( and/or supplier ) you use for exhaust inserts with 21-4n valves for endurance in a rally engine ?

**Graham** · 31-01-2021, 10:38

yes head is scrap, but unless someone is very heavy handed with cutting inlet seats dont really sink, when i fit big valves i position the valve as high as possible, which gives loads of room lapping in or future seat cutting. i leave choice of inserts to the people that fit them, but unless your using LPG you dont need really hard seats

**hawk1903** · 31-01-2021, 12:23

Many thanks Graham

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**Escort TC** · 31-01-2021, 20:27

I have give my Head with scrapped seats to a Company in Poland. Sie have grinding and welding the seats
In very good qualität for lead Free fuel.

**hawk1903** · 01-02-2021, 11:57

Hi,
Was there a crack in the seats ? I did not understand the " welding " part. Do you have photos what they have done ?

**Escort TC** · 01-02-2021, 19:24

No pic. She have grinding like a Insert mounting and then welded and seats grinding. It was no crack. The seats where totaly wrong grinded

**hawk1903** · 01-02-2021, 20:51

Originally Posted by Escort TC

No pic. She have grinding like a Insert mounting and then welded and seats grinding. It was no crack. The seats where totaly wrong grinded

I understood. He build up a seat there by welding then grinded like a new seat.
Actually very interesting, I haven’t seen/heard such a seat repair before but seems that a creative approach.