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yeah honda guru's i have the d15b motor and I want a little more power, i already have the basic upgrades extractors, exhaust and intake. but i want a little more power and no i dont want to change the engine and i want to keep it N/A. So i was wondering about shaving the head, is this a good idea and can you guys give me some pros and cons of doing this and a price range.

Oh and where can this be done SAFELY

Shaving will interfere with yuh cam timing a lil bit. You can mill the head .003", get an adjustable cam gear and hit the dyno.

Then save yuh money and buy a cam.

i was told not to try this procedure in trini, but you could try to get a metal head gasket
it lowers the compression or something so......!

wouldnt d man want to raise compression?

white_lion wrote:i was told not to try this procedure in trini,

where you hear dat. whoever tell you dat talkin ahh pack of rubbish ..................... dey musbe tell yuh bout port an polishing?????
oh yeah, an wha cleric said

I wouldn't suggest you do it for one simple reason, if your engine ever (God forbid) overheats and the head gets warped, if it was shaved before you won't be able to shave it again, you'd either have to replace the head or the whole engine.

Better bet is to go with a thin head gasket for this application, check ADAH 303 to see what he would suggest.

white_lion wrote:i was told not to try this procedure in trini, but you could try to get a metal head gasket
it lowers the compression or something so......!

firstly why not in trini
secondly..why wouldhe want to lower the compression...hes staying N/A

thinner head gaskets raise compression ratios slightly.

cuz dosent higer compression give more HP?

Lion, u might have mistaken port and polish for milling the head. P&P is a black art that not everyone is good at, hence plenty ppl don't recommend u risk a good head locally... particularly n/a apps.

As far as milling the head, any good machine shop can do it. You can find compression calculators on the net that can help you estimate how much you will want to mill and the corresponding compression increase expected based on which head, which piston, combustion chamber volume, etc... it's possible you may have to CC the combustion chamber (a method of volume measurement) to accurately calculate your end compression. (You don't want to go too high in CR to avoid pinging on our crappy premium gas)

As far as the head not being able to be milled again... that's only if you mill it HEAVILY the first time... there's only so much material to remove. But a mild mill will leave you room for mistakes (warped head). Again... a good machine shop can measure and tell you where the limit will be.

Cam timing ? No worries mate ! Yes, cam timing (and ignition timing to a lesser extent) is affected somewhat, but it will be negligible and will likely favour a shift to top end power, which essentially takes away from your low end... but guess what ? Your increase in compression from the mill will compensate for the difference somewhat ! Putting on an adjustable cam gear and re-tuning on the dyno can only make things better, but don't frighten if you keep a stock cam gear... you will still see power gains. The reason the shift in cam timing is not as detrimental on a sohc is that overlap is not affected since it's built into the cam.

HTH

thanks x2 but can anybody recomend a good machine shop that they went by already and was satisfied with the results

Heard good things about Baldwins.

10.1 piston and cams..
pistons
149187 75mm/2.953" STD. 3.327 5.276 1.213 38cc 10.5:1 3.7cc 241grams $415.00

cams
Stage 2 - Street/Strip with slight lope at idle due to increased primary and secondary lobes.
good to 7500 rpm...
and chip ecu

mill head 30 thou,. get a good adj cam sprocket (2-5 deg Advance), new Honda head gasket/timing belt.Have fun,enjoy.

I am from Trini and I port and polish honda head in USA and the guys here love it.....so what is the difference between me and another good local guy/? Why local guys not good at a simple thing like that?
that is not right man..........I know we did some work on our rx7 in trinidad that when I show guys in usa they bawl........they cant belive how cool and advanced our little island is

we dont have benchflo testers to properly pnp.
we just guess

flowing is great as a guide, but if you have enough experience, confidence and some artistic ability you can do a very good job.....remeber that a flow bench is just a static number which changes dramaticaly when you bolt the head to and engine

your money
go brave

I agree that a flow bench is not the end all test of a PnP job...but ziig, if you ported heads before...you should know full well that porting a rotary is not quite the same as porting a conventional OHV setup, so I dunno where you feel you going with that ?

As mentioned before it,s not recommended that you mill a Honda cylinder head more than 50 thou. max.You definitely will need an adj.Cam Sprocket/Gear(Edelbrock/Unorthodox Racing).If you got dollars go with a set of high-
compression pistons(Arias/SRP)10.5-11.0,if your engine has Vtec a Crower
stage 2 cam with heavy duty valvesprings,ARP head studs and oem gasket'
Unless you have a flow-bench and dyno, I would not do anything radical
with the ports,jus clean up the sharp edges and port match the head and
manifold using the intake gasket as a guide. Honda spent millions of US doll
-ars to engineer the stock head.

honda heads are ported very well from the factory.

dizzEK3h wrote:As mentioned before it,s not recommended that you mill a Honda cylinder head more than 50 thou. max.You definitely will need an adj.Cam Sprocket/Gear(Edelbrock/Unorthodox Racing).If you got dollars go with a set of high-
compression pistons(Arias/SRP)10.5-11.0,if your engine has Vtec a Crower
stage 2 cam with heavy duty valvesprings,ARP head studs and oem gasket'
Unless you have a flow-bench and dyno, I would not do anything radical
with the ports,jus clean up the sharp edges and port match the head and
manifold using the intake gasket as a guide. Honda spent millions of US doll
-ars to engineer the stock head.

just to be certain dizzEK3h, you're suggesting the high comp build as an alternative to milling... cuz high comp slugs with big lift camshafts as well as a milled head will prolly bend valves, ney? you'd need to clay if you're to be certain...

why rish milling the head and putting valves closer to pistons?
u gonna break something, its just a matter of time.

i suggest u do some proper research on your build.
raising compression by milling the head.
as previously stated, your cam timing is thrown off.
ignition timing it thrown off too.
you gonna have pre ignition unless u run race gas.
alot of other stuff too.
the proper way to raise compression is to use domed pistons

As mentioned if using hi-comp pistons(10.5-11.0) you do not need to mill
the head.I also suggested a stage 2 cam,which will work.However if you use
a stage 3 cam(race-cam) you may have interferance-valve/piston. It,s up
to you or your engine builder to check the clearances.Also a stage 3 cam
will give you poor drivability on the street,similar to guy,s who put racing
clutches in their gearboxes an beyotch about it.If you are building a street car
don,t put components for a race car in it. Jus my opinion.-good luck with the
build.

exzactly.
when u raise compression, i would advise a stage 2 cam.
works best for a street build.

what are you tryin to achieve anyways

I say...mill the head to 80 thou, weld in a 2" deck spacer onto the block, throw on some apex seals around the cylinders and yuh ORN....

I WASNT GOING NO WHERE WITH MY RX7 COMENT, it was just a eg of the fact that TRINI guys have the same potential to do GOOD work as US or UK or any one else.
As for B16 heads, dont mill them there is no need, go with aftermarket pistons and sleeves and you will run great.
I have ported B16 heads and gained nearly equal exhaust flow on my superflow bench as with a DART B16 believe it or not I was shocked!!!
However the INTAKES are much harder to acheive and was very illusive to gain the needed 10%
BUT its all up to the individual as to his needs and WANTS (different things)

PS i notice when I post I get certain guys being hostile and cutting my words down...if I talking sheit well I sorry , but if you talking sheit I dont say you dont know what you saying ok...so please lets exchange info with out hostilities if we can...( NOT AT ANY ONE PERSON)

i personally would not let anyone in trini port my head.

ziig wrote:I WASNT GOING NO WHERE WITH MY RX7 COMENT, it was just a eg of the fact that TRINI guys have the same potential to do GOOD work as US or UK or any one else.
As for B16 heads, dont mill them there is no need, go with aftermarket pistons and sleeves and you will run great.
I have ported B16 heads and gained nearly equal exhaust flow on my superflow bench as with a DART B16 believe it or not I was shocked!!!
However the INTAKES are much harder to acheive and was very illusive to gain the needed 10%
BUT its all up to the individual as to his needs and WANTS (different things)

PS i notice when I post I get certain guys being hostile and cutting my words down...if I talking sheit well I sorry , but if you talking sheit I dont say you dont know what you saying ok...so please lets exchange info with out hostilities if we can...( NOT AT ANY ONE PERSON)

Ok den... I go say it... yuh talking sheet.

ziig wrote:TRINI guys have the same potential to do GOOD work as US or UK or any one else.

agreed! seem to remember some years ago ziig had been contemplating returning home with a pro shop start-up on the brain... he'd been working with flow equipment then and perhaps this is all that limits trini potential from being realized... equipment availability and the like.