452 Heads valve springs

[78cordoba]

Recently i picked up a set of 452 heads and i noticed the valve springs on the exhaust side have different springs and retainers than the intake side. Im still learning so bear with me here. If im looking to to get new springs how should i go about this. new aftermarket or new stock ones its one a 400 78 cordoba lean burn delete, kiethblack pistons with valve relief. and its gonna have a stock roadrunner cam just looking for a cruiser nothing crazy. part numbers of springs would be awesome thanks!

 

[69Bee]

The shorter exhaust valve spring are usually to compensate for the larger "Rotator" valve spring retainer. If you get new springs, get the matching valve spring retainer set which would eliminate the exhaust rotators. I have never seen BB Mopar heads with rotators that I can remember, so I had to search images, and found one pic. It doesn't look stock and the exhaust springs look to be conical, like someone was trying to make them rotators. The funny thing is, all normal Mopar exhaust valves with 4 keeper grooves, wait for it....... MAKES them rotate already. The only reason for rotation is to prevent deposits from keeping the valves open and burning. On a side note, if you rebuild you heads, all of the keepers should be replaced, especially the exhaust 4 groove keepers. There is a lot of wear in the keeper and valve grooves if you check. Back in the day, replacement valves included new keepers with exhaust valves.

 

[PRHeads]

A few pics of what you have would help get everyone on the same page.

I seem to recall getting a set of Chrysler Marine BB heads in the shop years ago that had ex rotators and 2 groove valves.
If that’s what you have, I’d replace them with the normal 4 groove valves/locks/retainers.

My preference is to modify the guide bosses to accept the more effective positive valve seals.

 

[66chargerpat]

I wonder what the ex. valves look like. Did any bb heads come with sodium filled ex. valves?

 

[78cordoba]

 

[PRHeads]

My guess is if you pulled off one of those ex rotators, you’d find a two groove valve.

Then, you could pull the valve out and see if the stem was 3/8” or 7/16”.
The 7/16” stem valves are normally sodium filled(they will still be 3/8” at the top).

 

[F4R/T]

Motor homes and industrial engines may have , I wouldn’t put it past Chrysler engineering..Someone will chime in

 

[78cordoba]

Ok awesome thanks all. I will get them apart and and get back to you all.

 

[khryslerkid]

I modified my 452 heads for heavier springs and went with the positive seals. You won't have to go this extreme but there's some tricks included plus some of the inexpensive tools involved. You'll more than likely just need the cutter for the positive seal if you go that route.
https://www.forbbodiesonly.com/moparforum/showcase/reworking-452-heads-for-new-springs.4648/
https://www.forbbodiesonly.com/mopa...-452-heads-for-new-valve-springs-part-2.4657/

 

[78cordoba]

I modified my 452 heads for heavier springs and went with the positive seals. You won't have to go this extreme but there's some tricks included plus some of the inexpensive tools involved. You'll more than likely just need the cutter for the positive seal if you go that route.
https://www.forbbodiesonly.com/moparforum/showcase/reworking-452-heads-for-new-springs.4648/
https://www.forbbodiesonly.com/mopa...-452-heads-for-new-valve-springs-part-2.4657/

 

[78cordoba]

Late update the intake has positive valve seals and the exhaust has umbrella and they are all two groove valves

 

[78cordoba]

Are two groove valves not strong enough for a low budget cruiser?

 

[PRHeads]

Provided the valves themselves are in serviceable condition, my only concern with running the 2 groove exhaust valves is how they may impact the spring installed height.

Thats easy enough to verify by test fitting an intake retainer on the exhaust and measuring the installed height.
My preference would be to be able to run the same springs on both intake and exhaust, so they need to have similar installed heights.

Personally, for any performance application....... I wouldn’t use the exhaust rotators.