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Discussion Starter · #1 ·
does anyone know where i can find a set of titanium valves for my b20....i'm thinkin about just gettin tha head package from gude but i got a ported and polished head but the valves are bent i'd like to have a spare head...any sugestions (i know i cant spell)
 

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Why are you after titanium valves?

Their main benefit is being lightweight, which means you can have more insane cam profiles at high rpm without valve float.

Given the fact that the B20 can't go above 7k or so, they wouldn't be useful really at all.
 

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get titanium if you want em. they are stronger...by quite a bit and lighter as well. but for an N/A setup its probably not necessary.
 

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Discussion Starter · #6 ·
i was going to get get my cam from gude but yea yall are right and stainless would probabily be easier to find im already runin a high 15 so im hopin port and polished head and more agressive cam and valve work will get either low 15 or high 14....thanx for that info guys
 

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Well with an extreme cam regrind, you might like the safty net they offer... if you are getting close to the max lift stock will take... mabye.. hehehe not 100% sure. still resarching myself, as im looking at some agressive ideas

again mabye mabye not hehe
 

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Valves

The Guy's are right the money spent on titanium would be better put on forged pistons, or Rods.
I've just been doing some work on my 2G Lude B20A engine and have started flowing that head, not sure what a 3G head port looks like but the 2G one has loads of potential for increasing flow and further more huge potential for bigger valves, with stock seats you can easily go with 34mm inlet valves and then the exhausts can go upto 30mm easy, was looking at getting Set of 8 stainless steel inlets and having them machined down to 30mm as the stem length appears to be the same and they all use the same retainters and collets. With a N/A or Turbo bigger exhaust valves will really help especially as you'll be able to get much better seat cuts into the head to help flow more mixture through.
I've seen sets of stainless steel valves for sale but only stock valve sizes if you have any luck finding any bigger ones let me know but as i said inlets could be converted to exhausts.
 

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i beg to differ. titanium valves are useless with stock cams, but with higher lift and more aggressive cam profiles, they will actually make a difference. one thing i never mentioned when i was doing all my cam research was that even the stock cams showed very very slight signs of valve float. it was extremely noticeable, but the signs pointed to only a very very faint amount of float. and it wasnt just on one set of cams. it appeared on every single set of cams i tested, and on all sets of cams i didnt test that i took a good close look at.

titanium retainers might be all you need, or simply stronger springs, if you go with bigger cams. but titanium valves deffinitely wouldnt hurt.

btw, port and polish IS totally useless on any n/a 3g motor, no matter what the setup is. a turbo 3g, its a different story, but for n/a they flow more than enough potential volume. by port and polish, i mean port matching, enlarging the ports, and smoothing the ports to a near mirror finish.
if you are going n/a, keep the ports the stock size, they are perfect how they are. simply get the head and intake mani port matched, then have the ports polished, thats it.

on n/a setups, every single engine i've seen that had the head ported actually lost power. if you know the concept of air velocity into the combustion chamber, and know how to calculate proper port sizes, you'll understand why the stock port size is practically perfect.

you're much much better off investing in cams and titanium valves then having the head ported if you plan to stay n/a.

btw, i'm doing 2 seperate group buys for cams in the near future. one within a week or two for b18 intake cams already machined to fit directly in a 3g motor, and one sometime in september for colt cams's tri flow cams. for info on cam stuff for us, refer to this link...

http://www.preludepower.com/forums/showthread.php?t=242616
 

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P&P Heads

I Beg to differ if someone said what you've just said to me to do to a head i'd run a mile they clearly don't know how to work on heads, it shouldn't be termed Port and polish as it's completely miss leading and isn't the true nature of headwork. I work on many heads from Lotus heads to BMW as a hobby and as such i'm under no time constraints so i can go over every tiny micro detail inside a head without worrying about rushing to get finished. Each head i do can take upto 100 hours of work each usually 5-6 solid weekends 12 hours a day to get the head the way i want it. Obviously advances in CNC head work has reduced labour time for pro's but for me my time costs nothing so still cheaper!!
Your correct in saying that polishing does nothing and enlarging the ports on Modern Honda engines is again pointless as they are allready huge in some cases to big!!
But to say that there's no difference at all on having head done on a N/A engine is rubbish, the problem is a lot of people sometime jump in at the deep end and have headwork done, a lot of so called head specialists are cowboys and can wreck your engines performance, but people who know what there doing off such as myself and a handfull of specialists can improve even a stock engine.
People quite often have the headwork done but don't have anything else modded on the car, a CAI isn't going to make a difference and even having a modded stock TB won't help you need a bigger one, and having a very good exhaust header and system is a must. Also bigger injectors increase in fuel pressure then the biggest problem is with the ECU it's not clever enough to work out that your engines now got the potential to flow more air and fuel so more importantly it doesn't add the extra fuel and you'll find your running really lean which can lead to overheating and eventually engine failure. The Biggest Mod to do with Headwork is with a Custom ECU you either go OBD1 but better still is to go with Custom crank fired setup such as Electromotive, Omex, Alpha, etc. That way on a rolling road the fuel map can be properly worked out a tested to make sure that the Air/Fuel ratio is bang on.
Also another major thing that's often missed is that with headwork it's having the cams changed at the same time that really benefits from the freed up airflow and you'll find that on a stock engine a more aggressive set of cams will only rev to 7k rpm on a head thats been worked on this can increase from anywhere between 500-1000rpm extra on top provided you don't have stock ECU which will off course stop at just over 7k!!

Now someone who know what there doing of with Heads such as myself will give you a few options. They should give you a break down such as what will follow:
1: need the CAI
2: need your Throttle Body (Aftermarket or Stock)
3: Inlet manifold (Stock or Aftermarket)
4: Exhaust Header (Stock or Aftermarket)
5: Head and a Head Gasket kit for Head

Work to be done on a professionally done head should go along the lines of the below.

1: You need the CAI to match to the Throttel body which i would start by knife edging the outside edge of the inlet port, then making sure that the spindle is smoothed over and that the screws if not allready countersunk are replaced with countersunk and that the head and screw end are ground flush with the spindle, the butterfly would also get knife edged and the inside of the throttle body that mates upto the inlet manifold would be enlarged too, the inside of the inlet manifold would be matched to that new size as well and the gasket for the TB matched to the new size.

2: the stock/aftermarket plenum inlet manifold i would have worked on the inside should be as smooth a finish as possible almost polished you can polish but no point as it really makes next to no difference. This can be done halfway up inside the manifold but the rest may need to be done by sand blasting or similar. With a Turbo engine the inlet manifold should be matched to head inlet ports, with a N/A engine the inlet ports face that meets the inlet manifold should be radiused into a nice bell mouth shape or trumpet shape, this should be enlarged to the point where it covers over the whole on the inlet manifold port area.

3: the valve guide and ramp should be heavily worked on and made less obstructive to air and fuel flowing past, this can be worked into a fin like structure, also the division between the two valves should be knife edged and any casting marks cleaned up and removed, do not bother making ports bigger they are allready the right size. Next up is machining marks from valve seats being put in should be blended into the inlet port throat area and the valve seat, but do not port out the valve seat any bigger just enough to blend the throat into the seat, if you do this will reduce the amount of bottom cut you can have on the seat and will severly reduce performance. You will have no option then but to put new bigger valves in to restore the shape of the seat.
Inlet ports on a stock or Plenum style inlet manifold should have a reasonably rough finish to the fingers touch this will help mix the air and fuel better from having the injector so near the combustion chamber, i go one step further and put the valves in a lathe and on the area that protrudes into the port right down to the edge of the seat i reshape the valve into a nice trumpet shape and then get a course grinding stone and grind a swirly pattern onto the surface of the valve, this helps improve air mixture even more.

Exhaust ports and guide ramps should be treated in exactly the same way but they may have a near perfect polished finish and the valve again has a polished finish not rough. the valve guide should be reshaped into a more aerodynamic shape but in reverse as air is flowing in opposite direction.

Now for those of you using ITB's or Twin choke Weber carbs you will have a different inlet manifold and will be nice long and straight, the fuel mixing alos takes place at the top of the inlet manifold in the ITB's or the Carbs, so having a rough fininsh in the inlet port and valve is a bit of a no no, want you want is not a polished finish but a smooth to touch fininsh with a Matt look to it, this shoul dbe continued into the inlet manifold but as you work along towards the ITB's or Carbs getting gradually rougher and rougher, also the end of the inlet manifold should be radiused and bell mouthed and again should extend over the size of the ports on the ITB's or Carbs, on the end of the ITB's and Carbs, should be trumpets which you can experiment with different lengths and shapes to see what works best, generally shorter inlet manifold and trumpets is more bhp but less torque and longer trumpets and inlet manfiold means bit less top end but more low end torque this is general rule of thumb but sometimes some engines just love really short manifolds and trumpets others really like long ones such as B20A. Depends a lot on the stroke length longer stroke engines tend to like longer trumpets and manifolds.

4: the valve and seat are the biggest restriction in the head and with this area correctly moddified will give you the biggest gains on any head. The most basic seat to have done is a 3 angle but you can go further by having the angles machine edges radiused this is a good fast road seat to have done and obviously you need to have a smaller seat to have any good gains so for fast road use 1.5mm seat is as small and big as you should have for the size valves we have. You can go with 1mm which is what i use but you'll have to re-cut the seats every 20-30k miles i use 1.5mm seats on the exhuast valves for better heat soak away and realiability. The bottom cut should also be the largest you can get on the seat even if it mean blending into the aly on the head, the smaller the 45 degree seat the biggier the 60 degree bottome cut you can get.
A race seat would be 5 angle which in a effect is above but a bit smoother in overal shape much more like a trumpet/funnel, but next step from this is again to radius the edges of the machined angles this will make it into a near enough perfect trumpet/funnel shape and is often called a radiused valve and seat this is the ultimate and most costly as it's very time consuming as it has to be hand finished on each seat and valve.
The next important thing is that in the chamber that the valve seats are also machine flush into the chamber roof, and that any excess material around the vlave on the chamber walls is removed right upto the bore walls on the block. Unshrouding the valves in this way helps the air and fuel flwo in and out much easier. Also chamber should have really smooth/near polished finish but don't go too mad as even the best polished finish only last a few miles before it gets completely covered in carbon.

5: Bigger valves are a must for high performance and can get impressive gains from even stock cams, bigger valves does not mean you need to then get bigger ports and bigger inlet manifolds are anything else bigger, what it enables you to do is to create a much nicer shape to the valve seat and the valve head, this is what creates the extra flow not being able to bore out your ports and thoats bigger if you do this you will kill the performance of the engine and the head, the better the shape of the seat and valve the better the performance you'll get from your head this is critical. Improvements from bigger valves dues to the better shape of the seats and valves can have a dramatic effect so much so that you may need bigger TB and inlet manifold or it will be a waste of money, also your engine will sound a lot more aggressive and will have a much louder exhaust note, the louder your engine sounds from each bit of headwork you have done means you rheading in the right direction as your getting more air and fuel into the engine and more air and fuel makes a biger bang which not only gives you more power but makes a louder noise!! Also at the same time if you can increase the CR ratio of the pistons or by shaving a bit from the head and block you'll get huge gains from 15-30bhp depending howmuch you increase the CR ratio to.

6: the exhaust manifold stock can be moddified ports enlarged and cleaned up and then matched to the head and the downpipe, if using aftermarket then just match to the head.


Now as you can imagine this is an awefull lot of work and would cost quite a few thousand in labour time so as you can imagine someone who says yeah i'll do you a head job for $500 is an amateur and not worth wasting money on as it will do next to nothing and possibly make things worse than stock. This is 80% of the scenario involved and the rest is down to poor parts matching and lack of proper tuning. The guy's who get it right first time such as myself and a few other DIY hardcore tuners all have awesome cars.

BTW my N/A ET1/ET/A18 engines depending on camshafts used put down between 190-200bhp for a 2.0l 12 valve SOHC that ain't bad but i'm not done and these are on stock blocks with low CR ratio A20A1 pistons, the next engine i'm working on is having even better custom made valves all bigger, and custom profile camshaft, and the block will have bespoke designed flat top forged pistons with only 3 valve reliefs (stock has 4 for cheaper production) and uprated Eagle titanium rods and pins which will have CR ratio of around 12:1 instead of a really lowly 8.8:1 so will be looking at between 230-240bhp maybe a bit more.

Also working on a B20A 2G Lude engine with some mods as above but with 82mm B18C pistons, and H23 Rods, with bigger valves and Cat Cams 278 degree duration cams a 11mm lift should good for an easy 250-260bhp.

Check out my website has pics of everything including my modded 210bhp/300lbft 2.0l diesel engine which is in my BMW Msport 120d.

http://www.cardomain.com/ride/281725
 

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port and polish is different than port match and polish. port and polish means enlarging the ports, polish is self explanatory. port matching doesnt enlarge anything, it just matches the mating surfaces perfectly so theres no protruding flat edges at the mating surface for air to hit and get stopped by or cause turbulence.

stock port size is practically perfect for any form of n/a setup, even with huge cams. port matching always helps at least a lil bit, cuz the mating surfaces of the head and mani are rarely perfectly the same. polishing usually helps a bit, cuz the stock head and mani are cast, and are rough and have casting flaws. polishing simply removes the casting flaws, and smooths the runners and port. before the fuel injectors, a mirror finish is ideal. after the injectors, a smooth but not mirror finish is ideal. ie: grinding and sanding the ports to smooth them out more then stock and to remove the casting flaws, but not actually polishing them to a mirror finish. leaving them ever so slightly rough still, causes a very minor amount of turbulence to enhance air/fuel atomization (mixture).

chances are fly, you got a street port and polish. which is simply a port match and polish, no enlarging of the ports. a race port and polish is typically enlarging the ports a bit along with port match and polish. there is a difference lol.

edit, WHOA! holy novel haha. that wasnt there when i was typing this. lemme read this and see whats in there. and i thought I typed long posts sometimes haha

wow, rjudgey, i dont think i could have worded it better myself lol. that is pretty much the point i was trying to get across, but you did a hell of a much better job than i did.

rep point added!!
 

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headwork

No probs,
written longer ones in the 2G section the guy's love me there ;0)
I jus share what i learn because i've spent thousands in the past on people who reckon they know what their doing off and in fact there just amateurs. My ideas and designs are all R&D on actual heads that have been used in anger on track racing and drag strip racing and over the years i've learn't how to build my own race spec engines and also become rather good at tuning Weber and Dellorto sidedraught carbs which is handy, now i'm learning more about Fuel injection more on the ITB side though as you just can't beat the glorious noise of 4 cylinders breathing through their own choke!!

Anyways i'm allways online here and if anyone needs any advice on anything Head related or aftermarket carb related i can be contacted on PM or e-mail.
 

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I'm curious how Motoxxxman measured the valve float.
 

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The b20a5 head gives BIG(like, 20% and still good velocity) flow gains on the exhaust side from some basic head work.
The intake side gives very little, 1-2% at most.


One of these days i'm going to have my head given a once over, along with a header it should give some decent gains.
 

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Valve float

I've not experienced any yet maybe your springs need changing, but they are doubles but i have noticed that when i stripped down a spare head they are on the tad weak side, Cat Cams does uprated ones for B20A maybe they'll fit the 3G lude ones too as the valves appear to be the same.

As for increasing flow on B20 on the inlet side i can get way more than just 1-2 % increase in flow on inlet there is loads of potential on B20A if you can send me or post a pic of an inlet port so i can see if they are similar to B20A then maybe i can make better judgement on what can be donw to improve things to gain more than 1-2%, hell just doing a 3 angle seat and radiusing the edges and machine marks will give you way more than 1-3% increase in CFM. Having a custom stainless steel valve with 1mm oversize with race profile, guide ramp work, 5 angle radiused seat and valve head, cleaned up inlet port would give you loads extra cfm from stock.
 

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every single cam i have looked at from 3g's has wear marks on the cam lobes consistent with valve float, including the b20a cams i just received today for testing.

the thing is though, it's not only cfm that needs to be improved. it's cfm at specific vacuums and velocities. sure there is tons of potential for increased cfm in our heads, but not without losing buttloads of velocity.

with all the research i've done on our heads, which include hundreds of measurements and calculations, porting (enlarging the ports) a 3g head is pretty much pointless even if the motor is severely built. only way actually porting (enlarging the ports) the heads will show anything for gains is if you're high boost turbo and need all that extra airflow without concern of velocity.

porting to RESHAPE without actually enlarging the ports is a totally different story, something very few people know about, and most deffinitely dont know how to do properly, including myself. i have a very good idea on how to reshape the ports for better flow without losing velocity, but i wont even do much to it cuz i dont want to mess it up with one tiny mistake. i'm fine reshaping the tips of the valve guides that protrude into the port on both sides, but the ports themselves im not 100% comfortable reshaping, so i dont touch them.
 

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Headwork

Ah that would explain, sport shape is okay on the B20A just a little too much turn but then sometimes the extra turn can work to our advantage the B20A has excellent torque which is due to 1: the long stroke and 2: the extra turn that it has on the stock inlet manifold which continues into the inlet port, this gives excellent tumble results as the fuel and air enter the cylinder which results in the good torque numbers that these engines get.
As you said porting the inlet ports is pointless just need a cleanup and remove maching and casting marks, i even think that in most cases the inlet ports are too big and they could do with being round rather than oval, in some ways it's a good shape but depends on the shape of the inlet manifold and the length of the runners. The extra room in the inlet port helps slow down the fuel and air to help it make the turn and get pass and through the inlet valves. An ideal port and inlet manifold shape would be a round straight tube with trumpet shape entry and exit at both sides but this is not practical in 90% of engine bays and current fueling methods so were stuck with what we have for the moment. A lot of bike engine produce excellent power and this is due to there inlet manifolds and port's being aimed more at the above shape e.g. straight shot into the valves, with flared ends at both sides, only downside is bikes don't have much room so the inlet manifolds are really short if not non existent. One of the main reasons why the Mugen B20A produces so much power in the F3 cars their in is they don't have the same space constraints as normal cars or bikes and they can have inlet manifolds as long as they want, even with a 24mm inlet restrictor plate in place a Mugen B20A produces around 230bhp and due to it's excellent torque is still being used in some F3 teams today even though it was introduced back in 87.
Shame we'll never get to see any pics of the inside of the Mugen B20A would be interesting to see what they do to their own heads.
 
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