The Cal-look Lounge

Hello fellow loungers.... (and engine guru's)

I was wondering what can be done to exhaust ports for maximum performance... I'm building a 2017cc engine with 043 scat heads 40/35.5 valves... Intake port's are home ported (oval ports), exhaust ports are realy rough... (verry big guide boss)... comp ratio about 8.4:1, chambers 53cc...

Tips and tricks welcome!! ;)

Grtz Dennis...

ex port roughf and finish. the 1/3/8 ex flange exit will make more than atiquit power for what you are doing. all the work done in the middel and close to the valve seat. one thing to rember dont be the happy porter around the valve seat and under cut the shelf. try to leave the original radius SHORT AND LONG side. explaning how to do it is one thing but doing it hands on is another. use dull carbides and you wont get into trobel and lots of wd40. welcome to the grungy dirty job of head porting. UD.

Thanks for the usefull info en picts UD ! I'm confident to give it a try now  ;)...now i'm going to search for some cutting tools that are long enough that i won't knock my airdrill to the head.. Regards Dennis..

here is a little closer shot of this port. the OD of the exit is 1.450 on this port but not nessasary for what you are doing. UD .

Jeff, aren't those pics of CB 044 heads?
IIRC, the 043 does not have the same cast-in support for the guide that an 044 does.

no there not 044s. there a german casting 043 with full intake and ex bosses ;D me likey lots. got alot runin out there on the street. UD 

Jeff, those sure are "purdy".   ;)  Nice work.

Hey UD, what purpose has the welding on the fins on your heads? Your porting is real artwork 8)....i've got a lot to learn i suppose ;D.. How do you get that finsch in the intake ports?? Kind regards Dennis

I like your radial motor avatar, Jeff

the weld is there for structure being that these heads are design more like the oem style dual ports i do this to all my oem style street/race heads. the finsh is OLD JAPANESE SECRET. ;). UD.

thanks there jimbo. i like your fumigator fellar. UD.

Radial Jeff,
Check your mail ...
TexasTom

Hi Jeff
this is the same as i still do for street heads , but using original 040 or old 311 .  i also relocate and angle the spark plugs to get more clearance to manifolds

Udo

Same kind of head  this is my last 0.44, Is less open on the top of the pad for the valve spring housing (near the sealant face of valves covers)
 Do we have the same OLD JAPANESE SECRET for the finish?
A+
cedric

 8)

Nice ports in here.
My exhasut treating. Done on 044`s.
Check if the gasket doesn`t stand into the port, and open up the end conical if you are using a bigger header and bigger gaskets.
I freeed the port a bit around the guide and made it wider but not taller. I left the guide and made it conical.
The guide even has the function of heattransfer from the valve to the head to me. And you want to keep the exhaust valve cool for hot street.
Sorry I only have got a before pic...

One other thing I have done is to "open" up the outside area around the exhaust ports. The 044`s have many traps and grout around that area were no air can flow and is traped.
And when there is no flow no heat is transfered/blown away. I even connected the little "traps" with a horizontal hole.
Yust my thoughts...Engine is still in the building, so no exerience if it works or not.
Greetz!

Felix
the problem on your's will be that the guides can break away because the do not hold the heat of the exaust temperatureon the street . If the guides are protected with aluminium it is much better .

udo

Sounds reasonable Udo... I think i'll try to smoothen the valve guide boss on my heads a little more (for the flow) and to prevent quick polution of the port...

thank you all for your replies already!!!!! grts D

There's more you can do to port the cooling fins.  Look at the fins by the exh port in your first pic.  See the casting flash between where the 2 halves of the mould were?  Take a 1/16" cutoff wheel and run it through the fins at that point.  The flashing blocks air flow.

What about not matchport the port exit to the exhaust flange, leaving it smaller, creating a step 1-2mm maybe.. Should be good for antireverse. A lot of watercooled inline 4 guys do this. I have  also read that opening the end of the port dont help flow a lot. Any truth in this? Or you want the the hot gases fast out of the aircooled head in order to keep it cool, so is beter to have large exit.

thanks for the pictures guys, if you have more info/pic's post em here.. i'm making my plans for porting the 044'ers i've orderd.  ;D ;D

Already done  ;)
And even "freeed" on some other places. I can totally understand why the 044`s are known to get HOT.So much casting-flash...

It`s even a very good idea to smooth the area between the port and the valveseat. There is always a step standing into the port.

@ Udo: Thank you for the tip! I will cut down my guides a bit.

Did you make and install a deflector plate to go on the bottom side of the fins between the cylinders like stock heads have?