When a head arrives at our shop, it is first examined before it is even disassembled, and certain things are noted about the head, cam(s), valves, rockers, and springs.
We look for obvious and not so obvious problems and or potential problems. An example might be carbon build up, and it may be only in one chamber. A couple of exhaust valves displayed carbon, showing that they were running much hotter than those in the other combustion chambers.
This customer was not aware that the slight miss he occasionally experienced was a slight inconsistent air intake, and he was about to loose a piston, or burn a valve. Only 6% of the engine's power was lost, once in a while, so it didn’t show on the tune, and not on the dyno either, but showed up during our inspection of the head (common on about 7 out of every 10 heads we receive!!!)
Just another sealing issue; whereas, there were signs of "blow by" at the head gasket fire ring, (also another good indicator of problems). Loose, or worn valve guides, will cause oil to seep down the valve stem, and valve wobble, while cracked, or burnt valve seats can prevent valves from sealing when closed; worn or even loose valve seats are also common.
It's better to let a professional, who has the equipment, knowledge, expertise, experience, and the patience, keep track of the details, do what they do best, and use there services to your advantage. Get ALL that you can from your engine by making sure you cylinder head is working properly.
This is an excerpt from a letter, from an actual client;
Hey guys. Remember how I sent my head off to get it ported and polished? Well, I researched
several different companies and in the end I decided to go with Dan Paramore Racing. When I first called DPR, Dan
Paramore was available to help me over the phone. After talking to him for a few minutes I could already tell he knew
his stuff. He asked me what I wanted so he could advise me in what direction I needed to go. But unlike other companies
he didn't talk like he was better than me. Anyway I sent my head to them and they answered all my questions. Not only
that but he sent me pictures of my parts to show me the day by day progress. This is where I became amazed. Once I saw
the pictures and Dan explained each step to me, I could see that the amount of detail used by him and his staff is
amazing. Check out this picture of my valve.
(Actual client testimonial, name withheld upon request...)
custom machining was done to my valves they had to be measured to ensure quality and precision. Using the micrometer the
diameter of each and every valve stem was measured. After the initial quality was tested the valve was then machined
using precision machines to cut the special angles and radius of each valve. I thought this process was interesting.
They make a small radius on the intake valve margin, and a slightly larger one on the exhaust valves. Not only does this
help with the airflow, it eliminates the sharp edges so it resists detonation and pre-ignition. This is the same
procedure Dan uses on most of his cylinder heads. (some of which ran well over 50 lbs of boost.) I have never heard of
these kinds of details before. Every step the take they are so precise and particular. I have learned a lot of cool
details that you don't hear about or see at other shops.
companies, after the machining instead of the valves being cleaned by just solvent, it is cleaned in solvent and then
again in soapy water. The reason is that solvent alone cannot remove all of the metal particles from the machining but
using soapy water does, and the running water gets all off the remaining particles.
Once the valve is cleaned Microlon is applied at high
temperatures. This helps eliminate friction, and they also use Microlon as an assembly lube.
All of this just for the valves!!!! And that is just what he would show me. There is
more that he does behind the scenes. The springs went through a similar process. The springs were separated and then
were divided into the intake and exhaust springs sets. They came up with seat and full lift specifications based on my
cam and application as well as driving style and valve train weight. They asked me a lot of questions and they have so
many combinations to choose from and have so many combinations to choose from, they wanted to do they're best and get it
just right. Each spring was then tested to check pressure and to check for defects. The springs are then de-burred by
hand to prevent retainer wear and add durability. Then they were cleaned in solvent and then again in soapy water.
Immediately after that they were oiled down to prevent rusting. Many companies take the springs and install them without
any testing or cleaning. Like the valves the precision and detail DPR goes into is incredible. Next was to get
everything together on a tray, cover it up in a dust proof room until it is ready to assemble.
Now that all of the
machining and cleaning is done the valves are treated with Microlon and set under the heat lamp so the Microlon can soak
into the pores of the valve. This helps protect the valves from wear to ensure a long durable life.
Once all of the
machining is done the parts are then set on a tray to await the assembly.
There is still much left on this project, but
I just wanted to let you guys in on the info if you ever want any headwork done. I have been in engineering school for
three years and worked at a Honda dealership for four. After all these years, I am surprised ant the work that could go
into something when you do it right. When they send me some more shots I will share them with you also. Hey I'm back
just a short update for now. I got a picture of my rocker arms that Dan fixed. What did he do to the rockers you might
ask. Well as my car crept up to 130,000 miles a groove in my rockers was formed from my factory cams. And now that I am
putting in bigger cams, the groove from the stock cam lobes will not match with the cam lobes of the new cams. This
causes an increase in wear on certain areas of the cam resulting in poor life of the cam and rockers. What DPR does is
machine the rockers down until they are flat again so the new cams will be riding on virtually new rockers. I have never
heard of this anywhere before. Check out this close-up of my rockers.
Those are all the pictures I have for today. I will
get some more pictures of the final project soon.