port divider
- Thread starter mluck
- Start date
I can not answer your question from personal experience..
But…but
I can relay the information I have read from those with many many years of experience with engine performance:
That Is: They are basically useless.
My Conclusion: They are only a good thing to have if it makes you feel good having it.
PS: However before you take action on my conclusion keep this in mind.... I’m still having trouble selecting my cam…
But…but
I can relay the information I have read from those with many many years of experience with engine performance:
That Is: They are basically useless.
My Conclusion: They are only a good thing to have if it makes you feel good having it.
PS: However before you take action on my conclusion keep this in mind.... I’m still having trouble selecting my cam…
There was a suggestion on another string about what to do with the divider when it is in. The one suggestion that didn't involve taking the headers off was putting in a screw. He had a name for it, but it was essentially a small set screw, drilled through the header flange and pushing against the divider to hold it still.
All the other solutions involve taking the exhaust manifold off.
All the other solutions involve taking the exhaust manifold off.
Howdy Mluck and All:
You may have started yet another round of a virtually unanswerable debate. The only way to prove the effectiveness of installing a port divider is to flow test a stock head, then properly install a port divider and redo an identical flow test. Questions; did flow increase? did flow balance better? and probably other questions related to this specific change.
The problem is that no one will just install a port divider. If someone is going to the trouble of properly installing a port divider they will likely do some porting, a performance valve job, and more. So the addition of the port divider has just become part of a combination of changes- impossible to differentiate what did what, and how much. What do I gain, you ask? The port divider will help to balance flow and reduce heat under the carb mount location. I have verified those two issues on my modified head. That much I know for sure. How much power is a port divider worth? I don't know. It would be different in about every situation, depending on the total package.
I believe that adding a port divider is just one of the little things I do to get every last little ounce of performance out of my engines. Would I add a port divider without porting, polishing, valve work and seats? No. Would I try to install it using a short cut other than having it fitted, welded in and shaped to flow match the other exhaust ports? No.
That's my two cents, for what it's worth.
Adios, David
You may have started yet another round of a virtually unanswerable debate. The only way to prove the effectiveness of installing a port divider is to flow test a stock head, then properly install a port divider and redo an identical flow test. Questions; did flow increase? did flow balance better? and probably other questions related to this specific change.
The problem is that no one will just install a port divider. If someone is going to the trouble of properly installing a port divider they will likely do some porting, a performance valve job, and more. So the addition of the port divider has just become part of a combination of changes- impossible to differentiate what did what, and how much. What do I gain, you ask? The port divider will help to balance flow and reduce heat under the carb mount location. I have verified those two issues on my modified head. That much I know for sure. How much power is a port divider worth? I don't know. It would be different in about every situation, depending on the total package.
I believe that adding a port divider is just one of the little things I do to get every last little ounce of performance out of my engines. Would I add a port divider without porting, polishing, valve work and seats? No. Would I try to install it using a short cut other than having it fitted, welded in and shaped to flow match the other exhaust ports? No.
That's my two cents, for what it's worth.
Adios, David
mluck":38ovi6fh said:
The original Hooker dual out "Supercomp" header installation kit came with the cast port divider . The SuperComp dual outs' instructions called for the port divider to be ground carefully to fit into the head snugly with an INTERFERENCE fit. They said to leave a few thousandths or "just enough to feel" protruding past the flange and then use their gasket and bolts (small 3/8 heads) to bolt it up. Simple and can't rattle loose.
I used this method and it worked OK but found small amount of blowby/blowout around port/divider/gasket upon disassembly. I liked the idea brought up in previous thread of attaching a divider to the header flange by drilling through and tapping for fasteners but it is more complicated.
I had the machinist weld in the divider on the last incarnation of head I've worked on but I am waiting to see how his MIG work holds up with the cast head. Only time and temperature will tell.
Have Fuv
mysavioreigns
Famous Member
Hate to hijack, but, does the CI Dual-Out header require the Port Divider?
from what i'm told, the port divider never helped performance or hindered performance, i'm also told the siemese exhaust was developed for a reason, mabye it needed mroe heat for the carb, or it's a way to reduce the heat, either way we have absolutly no knowledge if a port divider increases any kind of performance.
I'm on the side of just take it out. I have dual header and no port divider, but it's my fault for not thinking about it first.
I'm on the side of just take it out. I have dual header and no port divider, but it's my fault for not thinking about it first.
I've run with and without it.
On my log head, I used a true hi-temp epoxy (as in, JB Weld WON'T work). It held for over two years and 20k miles without a problem.
I then did the same technique on my OZ250 head. Problem was that the OZ head did not have the ridges on the exhaust port so the epoxy basically had to make up the difference. (see below link, I'm too lazy to resize the picture)
http://www.kastang.info/pictures/65must ... vider4.jpg
This did not hold up well to the vibrations and ended up failing and rattling after about a year. I dealt with the rattle for about a year after that before finally removing the port divider and not installing a new one. Can't say I noticed any performance difference.
Regards,
On my log head, I used a true hi-temp epoxy (as in, JB Weld WON'T work). It held for over two years and 20k miles without a problem.
I then did the same technique on my OZ250 head. Problem was that the OZ head did not have the ridges on the exhaust port so the epoxy basically had to make up the difference. (see below link, I'm too lazy to resize the picture)
http://www.kastang.info/pictures/65must ... vider4.jpg
This did not hold up well to the vibrations and ended up failing and rattling after about a year. I dealt with the rattle for about a year after that before finally removing the port divider and not installing a new one. Can't say I noticed any performance difference.
Regards,
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