Valve seals with dry sump setup?

[65dragster]

I’ll start by saying I know almost nothing about dry sump oiling systems. A buddy just bought a set of Pro Topline 235 cast iron heads off a “trophy truck” motor that ran a dry sump. He was told that the heads would need to have oil seals installed because they aren’t used with a dry sump setup. I have no idea, but it looks like a blue seal can be seen through the valve springs. Probably need to take them to the machine shop, but I figured the crew here would know and could explain why no seals are used with a dry sump. Last question, even un-ported, are those heads decent for a 400+ inch SBC drag motor?

[Kevin Johnson]

The 2006 Ford GT used a dry sump and the online parts catalog lists valve stem seals.

I am seeing an OEM valve seal part number for the dry sump equipped Mercedes M100 6.9 engine.

So, at least two examples of OEM dry sumped engines used valve stem seals.

I am sure some/many builders do not use them but at least you have a starting point.

viewtopic.php?f=1&t=21420

[mag2555]

If the motor is not going to be run in a small 2000 rpm range with a dry sump then you still need seals.

[houser45]

It would be wise to use them on the intake guides, I do not use them on the exhaust. You do not need them and valve guide manufacturers will tell you a little oil on the exhaust stems will help with the life of the guide with no downsides.

[65dragster]

Good information. Any thoughts on the Pro Topline 235 cc heads for a drag application?

[MadBill]

The seal/no seal question does not relate to wet vs. dry sump; it's a matter of crankcase vacuum or not. The former, more common in dry sump systems, particularly with vacuum in the mid-teens or higher, reduces the pressure differential that helps draw oil down the guides and can starve them (especially the exhaust side) for lube.
Occasionally, seals are still used (more often on the intake) but in modified form, often by removing the garter spring that many designs use.

[Kevin Johnson]

Little bird chirped at a few dendrites and axons.

Seems like some full vacuum engines with dry sumps flood the heads to keep the valves springs cool.

Perhaps Jay would be willing to comment.

[65dragster]

There are seals on the intake but not the exhaust. For a drag race only motor and a traditional wet sump pan, will this work, or should I have seals installed on the exhaust side? If it has a slight puff of smoke on start up, that does not bother me.

[Kevin Johnson]

Little bird chirped at a few dendrites and axons.

Seems like some full vacuum engines with dry sumps flood the heads to keep the valves springs cool.

Perhaps Jay would be willing to comment.

Many old tech articles have been stripped, unfortunately.

viewtopic.php?p=40197#p40197

Post by cmw » Thu Nov 30, 2006 12:12 am
Valve spring cooling is the key for endurance of the spring. Coating springs has not proven to do anything. Coating with a moly or what ever you dare to spray on the springs is just not good. Reason being that there are binders that hold this stuff on the springs, but anyone that has ever done this knows that it does come off but the coating company they call it burnishing. Having moly in your engine is not good. It is like pouring sand in the engine. I say this because of all the scratches you find on cylinders, pistons, bearings and anything else oil gets in contact with. The Nascar engine builders are now flooding the valve cover to cool everthing on top of the head to controll cooling of valve train. I supply alot of the teams with a special spring lube and a oil additives.
Bob Cousimano
CMW Oil Company
CMW Motorsports Manufacture Aftermarket Porsche Billet Heads, Cylinder head Flow development, Engine Dyno Service

https://www.hotrod.com/articles/ctrp-07 ... der-heads/

Owner Matt Bieneman has gotten rid of the valve seal by using an O-ring inside the valveguide. The advantage of this is that it allows the guide to be taller (equal to the height of the top of the old valve seal) without limiting valve lift.May 15, 2007

ctrp_0706_07_z-r07_cylinder_heads-valveguide_o_ring.jpg

[naukkis79]

There are seals on the intake but not the exhaust. For a drag race only motor and a traditional wet sump pan, will this work, or should I have seals installed on the exhaust side? If it has a slight puff of smoke on start up, that does not bother me.

As exhaust valve stems leaking outputs oil straight into exhaust result isn't smoke on startup but when engine is on working temperature. With tight valve stems and not much oil in rockers that smoke could be pretty minor - but with loose stems and good rocker oiling result is not only smoke but also oil drops coming out from exhaust.

[Alaskaracer]

I run a dry sump on my stuff and seals on both intake and exhaust. I will not run an engine without valve stem seals. Even my buddies blown alky deal has them on intake and exhaust.....oil in the combustion chamber will cause detonation among other things.....there is no disadvantage to running them at all.....

[engineguyBill]

I run seals on both intake and exhaust guides on all engines, from street performance to maximum-effort race applications. I use positive type seals on all applications, my personal favorite is the Teflon PC seal, when there is sufficient valve spring clearance. One thing that is very important is to install the valves with maxiumum stem to guide clearance when installing positive type valve seals. This allows sufficient amount of oil in this location, if stem clearance is too tight the stems will gall and might even seize. The reason that I use PC Teflon seals is the fact that the have a slight taper towards the ID of the top surface of the seal, which acts as an oil reservoir thereby metering a slight amount of oil to the valve guise each time the valve opens.