easyvette

My engine builder turned me onto the Brodix Br7 series heads. Which after reading for a bit seems like a really nice head. I recently learned that Brodix does NOT use exhasut valve seals on the exhaust valves. Not only on these specific heads but all their heads they build. This to me sounds a bit concerning but after talking to my engine builder and speaking to a Brodix tech it is making more and more sense.

What they have both told me is the exhaust valve is not the suction side. And putting a seal on the exhaust valve will cause oil to build up in the intake. And also with the amount of heat coming from the exhaust valve the exhaust valve can become hung up having a seal. And further more not using an exhaust seal on the valve extends the life of the valve and the guide. As the valve and guide will get some lubrication.

Remember I am by no means a head GURU. But when I look at all the issues with the valve guide wear on this forum. And I talk to Brodix people who know something about building serious motors and heads. It really is something to think about. And for them not to install exhaust valve seals on any heads they make sell. Something is to be said there..

Dirty Howie

Interesting. Are they the only ones with this philosophy??


DH

easyvette

I do not know. But I do know they make alot of heads. I was just kinda curious when I read about cars popping so many exhaust valves and so much guide wear. I am just throwing information I received out there for discussion...

Too-Fast

OK, so this is interesting...never heard this.

Dirty Howie

Well I don't ever recall this being discussed here before. I do know that some in here have these heads so hopefully someone will comment.


DH

0Anthony @ LGMotorsports

We have used their heads and yes, they don't use it on the exhaust side and even sometimes on the intake side.

In some cases, removing the seal can allow more oil to pass by and lubricate the valve stem more than what it would with the typical wipe style seal. Of course this does also mean that the engine will burn more oil, so when you see a drag car fire up for the first time and they blow a puff of smoke, that is oil past the valve.

Most of the road race engines we have done all use seals, and the street cars of course use seals as well.

Brodix will put seals on them if you ask them to, and for most uses, I still say it is a good idea to have them there.


So no, they are not completely crazy but for a street car it is still nice to have them there.

easyvette

Thanks Anthony for your knowledge. I was talking to another member here with the actual heads installed. The member is experiencing significant oil consumption which was concerning. But with that being said after speaking with my builder and Brodix they recommended not installing the seals even though it was a street car. They are both assuring me oil consumption will be minimum. At this point I am going to have the heads installled without the seals and monitor the situation. Its hard for me to go against a builders and manufactures recommendation on a new product. At least before I try it.

C6z06man

Hmmm that is an interesting design. I can understand the use in a drag car where the run time is limited but street/road racing it doesn't seem like a great idea. Cool info though.

qwknuf6

GM did not use seals on the exhaust valve of Buick Grand Nationals , 3.8 Turbo Engine .

Too-Fast

This is very interesting, however I would not want to be starting my 'vette with little puffs of blue smoke coming out of the exhaust and increased oil consumption will cause other issues...does not sound like a good street solution to me, IMO.

Michael_D

Running a seal on the exhaust valve has always been an "option" for race engines. Sometimes I'd just throw an umbrella seal on them, but not always. So, it's not unheard of. But with race engines, as far as regulations go, they are "for off road use only".

Not sure if you misquoted Brodix or not, but to say there is no suction on the exhaust port is incorrect. Don't forget that fifth stage of the combustion process, the scavenging stage. That's why seals are there, EPA / emissions. That's also why the metering rate has decreased over the years and seals have morphed to the positive type we see now on most engines. - Tighter regs. For them to say that not installing a seal on the exhaust will cause oil to build up on the intake is also incorrect. I think you got that backward. There will always be some reversion as well, which will cause some oil to find it's way into the combustions chamber, but most goes out the exhaust.

Road machine

Oil seeping onto a hot exhaust valve is also a great way to build carbon on the valve and loose sealing. I would use a seal.