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yet another big valved anima build.

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Discussion starter · #22 ·
So I fixed my bone head move today and turned a couple new exhaust seats. Got the seats pressed into the head and all for port throats cut to size. I was going to hold off on doing the valve job til I got done porting. But curiosity got the best of me on the intake side. Like I stated earlier in this thread I'm really pushing boundries with doing 27mm intake valves. The intake seats are 27.5mm OD at the OD there is only 0.25mm/0.010" of aluminum separating the seats. As you can imagine it's tight. Being that it's so tight I had concerns that the top cut of the valve job would overlap onto the adjacent seat. With that being said I was a little anxious to see if I was going to be pissed off and have to come up something fancy to cut the seats. All went accordingly to what I had mathed out prior to the build. But damn there is no room for error if I set my cutter a few thousands bigger and it would of caught he other seat at I was cutting.


starting to take shape.



 my previous BV anima I starter a thread on I did 26mm valves. So I figured it would be a fun comparison to show



26mm valves sitting on the seats







27mm valves sitting on the seats
 
Discussion starter · #23 ·
Decided to go head and cut the exhaust seats so that I can figure out how much deeper seats need cut for the big lift cam regrind.



 this is the exhaust side. Even though the exhaust side has more room between seats the top cut is still really close to clipping tge other seat
 
Discussion starter · #24 ·
Last few days I have been working on the intake port. For this build it will get a 32mm pumper carb bolted directly to the head. After a second look the carb boot given had a through bore of 29mm. Well that's not going to work out so well woth the 32mm carb. So I went ahead and bored the carb boot

Now she's a cool 32mm through

It didn't take me long into porting to find out I have really pushed boundries on this head

Yes that half moon shape is a perforation into the spark plug hole. Ha ha go big or go home right? Being it's on the intake side I'm not worried at all about it. While I try not to go this stupid on customers stuff a lot of my personal heads have lil perf's from where I pushed it to the edge. With being said I know it won't be an issue.


Intake port darn near finished lil more blending/texturing around guide bosses and patch up the hole and she's done and can move onto the exhaust port

 
Discussion starter · #32 ·
mrrcx said:
What about camshaft and valve springs? What are your plans for them?
Click to expand...
Did a regrind on the cam. I forget rocker ratio but if memory serves should be around .340~.350"ish lift and 244 duration at 0.050. New lobe ramps required a seating of 60# and nose of 150#. I don't have my notes in front of me so I don't recall what bike the springs are meant for. But they meet the requirements 62# seating and 150# @ 0.350" lift. They are kibble springs ti retainers
 
Discussion starter · #34 ·
lumberjack91600 said:
sorry i didnt saw those pictures,i will try to make it on my 4v as motomans website reduce 30% the intake
Click to expand...
I can without a doubt tell you if you do motomans technique will lose power!

the pull labeled as small port (red line) was porting done exactly as motoman site explains to do. These pulls are done with a yx 4v kit. The only thing done to each was port work and nothing else. As you can see motomans 30% shrink work on any multi valved head is ABSOLUTELY bullchit
 
#35 ·
i don't understand Chad,i read the entire post you did when you work on the crf/hybrid xrYX

and i thought you where saying that dshaped makes more power... my english is probably to bad

to understand everything well...the black line its Dshape (as we saw on the pict of the 4v)but you didnt reduced it?
 
Discussion starter · #37 ·
lumberjack91600 said:
i don't understand Chad,i read the entire post you did when you work on the crf/hybrid xrYX

and i thought you where saying that dshaped makes more power... my english is probably to bad

to understand everything well...the black line its Dshape (as we saw on the pict of the 4v)but you didnt reduced it?
Click to expand...
Let me try and clear things up for you. First the graph I just posted is not dyno pulls of my mutant engine (crf/klx). A number years ago a buddy and myself purchased yx 4v kits. The graph I posted is the testing I did on his yx 4v head. Now with that said. At that time everyone kept saying you have to port it like motoman. I don't agree with motoman you can't slap a one size fits all type of deal on porting. There are a ton of things to factor when determining port size and shape. I do however agree with his basic concept that velocity and shape have HUGE effects on port flow and efficiency.

The graph I have posted has motomans shrink the ports 30% (red line)

The green line would be what most consider as a "clean up" port job. Knocking heavy casting off, giving the port a good uniform texture and blending the bowls. The clean up port job didn't really yield much in max power gains. Where you really saw the difference is smooth pull through the rpm range and more over rev.

Black line is the final port job. My buddy wanted a strong mid range power. This port job was D shaped and heavily worked.

The D shape port is a efficient port shape but just like motomans "shrink ports by 30% on any multi valve engine will make more power" the D shape doesn't always provide the most power in every application. The statement most power can be viewed different ways. Most guys only care what the max hp number is. Max hp don't always mean it's the fastest engine. In alot of racing applications power within the curtain means more than max hp values. So again as previously stated porting isn't as simple as use this shape use these dimensions for every application. The engine has to be viewed as a whole. Things like carb size, does it have a manifold or is carb direct to head, if it does have a manifold how long is it, valve sizes, bore and stroke numbers, long rod or short rod a long rid will dwell at TDC where as a short rid will dwell more at bdc,exhaust tuning....I think you get the picture.

So you may be thinking we'll chad most of your threads on here have D shaped ports. In my experiences and testing the D shape port has yielded the best gains throughout the rpm range. I ride/race mx and most of the guys that send me heads to port want a broad rpm range. But on occasion I'll get some extremist that want nothing but upper rpms. In which case I will usually opt for a square/squarish shape .

Make better sense now?
 
Discussion starter · #38 ·
Here we go. I can't find the finished pics. but here is about mid way through a head I was doing for a guy that was running methanol and was either blown or turboed, either way it wasnt a NA setup
 
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