[muscle_collector]

like the caption said, i havent built any engines in around 20 years. i am going to freshen up a set of stock ra 4 heads and do a valve job to run on todays gasoline. what aftermarket valves springs etc would you use and do you still just put hardened seats in them? going to use the factory ra4 cam thats still in it.

[SRGN]

The basics are are still the same, I've been using stainless valves, and inconel on the exhaust side for turbo applications. Hardened seats if not already installed. I have a friend with a Serdi to take care of the valve job.

[Dragncar]

Send them to Paul K.

[HWYSTR455]

Still don't understand why people put hardened seats in, 9 times out of 10 it does more harm than good. And you don't need them.


.

[P@blo]

Originally Posted by HWYSTR455

Still don't understand why people put hardened seats in, 9 times out of 10 it does more harm than good. And you don't need them.


.

My machinist agrees regarding inserts on a cast iron Pontiac head. My ported 670's were just gone through and I was advised against their use. He said it's my money though and would still install them if I wanted. Proof for me is the 6X heads I ran on my 400 for 25 years without inserts and no issues.

[Jay S]

The drop in valves spring for a RA4 cam with RA4 heads is a Compcams 987.

With hardened seats I think it depends on how much wear the heads have and how much the car will get driven. The cruising RPM’s effect the life of the seats also, if the car has 3.90 gears and sustains a lot of RPM’s cruising and will get driven a lot I prefer hardened seats. If the car is only going to get driven 10,000 miles over 10 years there is really no reason to bother with hardened seats if the seats are not sunk. I’d replace the factory tulip intake valves and use a 1 piece Ferrea.

I have been helping Schlange with his 68 project he bought from you.

[Shiny]

Originally Posted by HWYSTR455

Still don't understand why people put hardened seats in, 9 times out of 10 it does more harm than good. And you don't need them..

I'm curious. Can you share the downside?

If the seats have sunk and no longer useable, is there an option?

[John Milner]

I have been using a NOS set of stock style valves and Crower 68405 valve springs in my 614 heads for the past 12 years or so. The Crower springs work well with a Ram Air IV style camshaft and they set up at the same 1.7 height of stock Ram Air IV springs. I did not put hardened seats in the heads and it has had plenty of street miles on it with no issues. Hindsight, I probably should have went with a 1-piece stainless valve.

These would be a good valve 1 piece stainless valve for a street Ram Air IV head as they are the same length as the stock IV valves:
https://butlerperformance.com/i-3164...tegory:1459612

These Comp springs would work well with the IV camshaft:
https://butlerperformance.com/i-2445...tegory:1459605

I run those particular Comp 995-16 springs in another set of round port heads that are set up at 1.7. They work fine with the flat tappet camshaft and required no machining to use.

[HWYSTR455]

Originally Posted by Shiny

I'm curious. Can you share the downside?

If the seats have sunk and no longer useable, is there an option?

Downside is for one, finding someone installing them correctly, two, money, because you don't need them.

If the seats are sunk to a point where they need inserts, get another set of heads. 9 times out of 10, they are sunk because of poor tune or too many hack valve jobs.

I've run iron heads in every condition imaginable, daily drivers with big cams & higher than advised CRs, bumper to bumper traffic, crappy tanks of gas, you name it. And I'm not talking about a few thousand miles, my one 455 I had over 220k miles on it when a rod let go. I daily drove Pontiacs for over 30 years.

I've had valve jobs done to clean up the surfaces, and guides done, but never needed inserts. People just do it out of habit, and the hack shops insist it needs to be done. ($$). Or they just don't know better.

Show me a pic of a Pontiac head with 'sunken valves' to where it needs inserts.


.

[muscle_collector]

thanks for all the replies. keep the thoughts posting

[PAUL K]

Unless your existing seats are beyond saving, I'd highly recommend not installing hardened seats. Unless you're dealing with a shop that's intimately familiar with IV heads and familiar with air flow, there is a lot more that can go wrong and the chances of getting them right are far less.

I've seen one set of Pontiac heads that had eroded seats. They were used on a daily driver with a very fast closing camshaft. After 30k miles we did some additional work to the heads and the valve seats were beat up. Other than that one example I've seen zero Pontiac heads with seat recession over the years.

[Jay S]

From what I recall the factory installed spring height on RA4 is just over 1.8”. It takes some adjustments on the spring height to run a 1.7” spring. The 1.7” springs like the 68405 and the 995 Comps work ok though, but it usually needs a -.050” valve lock and a shim to get the seat pressure where it needs to be, that varies when the valve retainers are swapped with aftermarket versions.

[Half-Inch Stud]

Valveseat inserts weaken the Chamber. Maybe let some coolant get through, after some pinging.

Never seen a PMD iron head erode or sink the valves. Tis the Cam and Lifters to concern about.