Cylinder head prep

JPM

Member
Is there any other way to effectively heat cycle a new head other than running on an engine...track time?
 

fatboy1dh

Member
There are folks that claim "seasoned heads", but through my experience the easiest, most effective way is to run it. We have the luxury of a dyno. If you don't have a dyno, a practice day or track day is just as effective.
 

CarlsonMotorsports

Premium User
^ I'd agree. You could bolt a steel plate up to it, pop it in the oven, and let it heat up with some pressure against the seats, but I don't think that accurately reflects the localized heating and cooling that goes on inside the combustion chamber, valves, and seats. The valves constantly pounding down on the seats is what sets them in place when the aluminum expands quicker than the steel seats.

I suggest that our customers practice, practice, and practice some more. Then get the valves and seats touched up if you can.
We routinely get asked to "break-in" customer engines on our dyno. With the ring package that comes in the 206 from the factory, that would be an all day job (and then some) to honestly "break an engine in." With the cost of load cells, sensors, etc alone it's not a viable interest we have. The time/labor alone is not well spent in my opinion. Again, practice, practice, practice at your local track on some old tires and that'll break in your engine better than anything a dyno and operator can simulate. We run our engines on the dyno long enough to build some heat in them, then make 3 or 4 pulls. As long as it's up to our level of expectation, it's ready to hit the track. Realistically, a whole season later, it'll be broken in. :)


-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
30 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 

knighty

Member
I couldnt agree more......run it hard at the track, in Hondas it takes 20-30 hours to properly break them in.
 
Brian speaks "the word"! We run a 10 race winter season and a 10 race summer season here in Arizona. Trust me, after the summer season a new cylinder head will definitely require a little attention to the exhaust valve seat. After a "seasoned" head is serviced it rarely requires anything more than a valve lapping.
 

Jimbo

If you talk the talk you should walk the walk
Don't believe the guy that says the valve and seats are not right from the factory and he needs to do a valve job on a brand new engine. Also don't believe the guy that tells you that they will season the head of your NEW motor by putting it in an oven and then charge you hundreds of dollars extra to prepare that new motor for you.
1. He doesn't know what he's talking about !!
2. He's only after the money !!
3. Or both of the above !!

"The Rest of the story" Paul Harvey
Tel 920-207-9180
 
I can see the value of a seasoned (Heat treated head . That being 0 leak down from the time you bolt it down on an older short block . Its race ready . Most heads I've serviced after brake in have a significant drop in leak down. Many times this requires new valves due to stem warp and seat irregularities.
 

Jimbo

If you talk the talk you should walk the walk
Small world, deja vu or as luck would have it
I currently have an engine here that has a head on it that was seasoned in an oven before the engine ever ran. It has the most leakage past both valves that i think i have ever seen. As a result the back of the intake valve and the port are severely carboned.
It will get the seats machined and the intake valve replaced. The time and effort to clean the valve isn't economically feasible.
Keep in mind that using sand paper, a wire wheel or even a scotch brite pad could be considered polishing the valve and result in a DQ.
Cleaning the ports either with chemicals or ultrasonic is also in order.
 

jjchat

Member
I have been finding on newer heads that they leak down (particularly the Intake) significantly after a little running and then need to be touched up. After that they seem to to hold their seal.
 

CarlsonMotorsports

Premium User
I have been finding on newer heads that they leak down (particularly the Intake) significantly after a little running and then need to be touched up. After that they seem to to hold their seal.
That's right. It's been this way for a while now -- which probably precipitated the "heat treating" idea that someone has tried.
Once the seats take a set, touch them up and you're good to go for a long while. It takes 2 good race days on a new engine for the seats to settle.
Run it hard for a couple of races, have the head freshened, then run it the rest of the season if you like. There seems to be little to gain in recutting the seats more often after the first time the seats settle in. Keep in mind that the deeper and wider that you cut the in seat, the less it flows.
 
I like the idea of having 2 heads . Having a fresh head for every race pays dividends so to speak . Why would you ever go to a race half prepared. Heat treated or simply seasoned over time makes minimal difference when your touching up the seats with 2 heads . If your racing a big 2 day regional race or multi day national race weekend. Simply changing heads is a race day advantage.
 

Jimbo

If you talk the talk you should walk the walk
I'm sorry but i have not found that to be true.
If the head is prepared (done) properly they last a long time. I like to see the head raced at least 10 race days including practice time before it is what i would call seasoned. The more the better! I have found that if seasoned properly and then refreshed they can last a complete race season before being refreshed again. They may last longer than that but if you get it done during your off season then you know you have the best stuff for the start of the next season.
For a very large portion of the racing population removing and replacing the head on their engine is a monumental task. They may be the best driver but when it comes to replacing the head all the technical things that go along with it that simply isn't something they are equipped to do!
One of those critical things is is getting the valve clearance set properly.
I will be going to the CKNA finals in New Castle next week end and i will have large number of customers and engines there and i can promise you i won't be taking any heads off.
 
I'm sorry but i have not found that to be true.
If the head is prepared (done) properly they last a long time. I like to see the head raced at least 10 race days including practice time before it is what i would call seasoned. The more the better! I have found that if seasoned properly and then refreshed they can last a complete race season before being refreshed again. They may last longer than that but if you get it done during your off season then you know you have the best stuff for the start of the next season.
For a very large portion of the racing population removing and replacing the head on their engine is a monumental task. They may be the best driver but when it comes to replacing the head all the technical things that go along with it that simply isn't something they are equipped to do!
One of those critical things is is getting the valve clearance set properly.
I will be going to the CKNA finals in New Castle next week end and i will have large number of customers and engines there and i can promise you i won't be taking any heads off.
Are you speaking of 206's or all heads in general?
 

Jimbo

If you talk the talk you should walk the walk
They are all made under the same conditions and to the same specifications so they react pretty much the same way.
One exception might be a Kid Kart motor that doesn't see the stress / conditions that the others do.
Another exception might also be an engine that is raced in extremely hot locations like Phoenix, Az the deep South or Southwest USA.
The heat these engines operate under can accelerate the settling process and may also result in needing to refresh them sooner.
 
To each their own , Whatever works for you . There are a lot of diffrent ideas and methods. There are a lot of knowledgeable engine builders out there. Personally for me.When I put a engine on a race team kart were there to win." Good Enough " is not part of the conversation. Now I'm sure I dont service a lot of Engines like many do. But we do win our share of races . And while I like this site for reference and information .I dont use it to build my business. So my opinion is just that.
 
Top