Dilbones

I have several options to modify my cylinder head to make my engine faster for my racing class and they are as shown below:

• Deck the cylinder head (as long as it's not 0.5 compression points > than stock)
• Port and polish intake and exhaust ports AND intake manifold
  • has to be < 1 inch into the ports
• Valve-to-seat may be machined as long as OEM dimensions
• Brian Crower valve springs
  • part #68181-16

In order from first to last, which would net me the most power?

Any additional comments welcome, but if it's not listed above I can't do the mod (for the cylinder head).

K7-1Ktrevor

B16 intake manifold modified to fit ls heads is one of my favorite mods. It works really well for the stock ls torque curve and will help carry power up to about 7500rpm. Also it has better low end power then the skunk2 manifold due to the longer thinner runners aid in port velocity. As far as port work there's quite a bit of improvement to be made over the stock port shape and smoothness.

Dilbones

We can’t run different manifolds otherwise I would. I was trying to keep this specific to headwork.

when you say a bit of improvements to be made over the stock port shape and smoothness what do u mean?

BoostHatchFreak

port the **** out of the head, port the hell out of the stock obd1 intake,port tb opening to 70mm yes it make it, et a ebay tb that appers stock, itr stock header, go to junk yard pull every set of cams you can find bring a dial caliber find the biggest set youll be shocked by the differences ( or have a cam grinder regrind the stock cam) cut 403 off a set of crowler cams not bc. deck head just remember how much it will throw off your cam timing. so you will need gears. if you can instead run pr3 pistons aka b16a,2,3

# 1 porting head #2 tb opening #3 cams #4 decking head

K7-1Ktrevor

Biggest part is getting rid of the casting flaws of portshifting. You'll see an offset from where the valve seats were cut to where the port actually is. Usually a few mm step in one way or another. Also the short radius turn is sharp and can be taken down a bit to correct the airpath more directly onto the back of the valve .

Dilbones

Thank you guys this is super helpful. So it seems the ports are the biggest difference. I have some OD micrometers as well and two sets of camshafts. I can measure for the biggest and send that.

Are youbsaying OBD1 manifold is different than OBD2?

BoostHatchFreak

yes also if you can find a old first gen skunk intake for ls they look like a b16 intake but fit your head that would be best honestly. ya I found a set that had 5 more degrees of duration and .040 more lift then the smallest set I had ( I had 6 sets )

Dilbones

This is raelly good thinking.

What is different about the OBD1 manifold vs the OBD2? I'm raeding that the only differences are in sensor location. Apparently since the gaskets are the same, most people say the flow is the same.

I can't put a b16 intakeon my car, but I've read they flow better. Racing rules restrict this and the throttle body as well. I also can't touch timing gears.....

BoostHatchFreak

im not saying to us a b16 intake. I said get a first gen skunk 2 b18b1 aka ls intake. I stated they look like a b16. as in they have the same benefits if you put a b16 on. the first gen has no markings or anyway to tell its aftermarket. again cheap ebay throttle bodys look stock just not there measurements. ive always felt obd1 intakes run better. then throw out the idea of shaving the head or block then. what you can do is weld up the chamber. also have you though of using a p8r head?? much more power

Dilbones

ahh yeah, i can't do any of those mods...

BoostHatchFreak

you cant run a first gen skunk intake manifold? theres no way to know lol. tb you can get a type r which is a 62mm over a 60mm. also a type r header will help as well. why cant you run a p8r head its a non vtec head ?

Dilbones

If I ran an illegal manifold and drove 8 hours to championships to get disqualified I would be wasting 8 hours and hundreds of dollars if not several thou. Same with the TB. I currently run an SMSP replica header. I'm going to be wrapping that with heat wrap and doing throttle body coolant bypass and the hondata intake manifold gasket.

I can't run a P8R head because that's not legal per the rules either.

So I have to deal with the asthmatic B18B1 head...either OBD1 or OBD2. I have read that they're the same except for coolant port sizing on the underside of the head.

I was just trying to gauge what would be the best bang for buck mod for a cylinder head without spending a fortune.

wunfstgsr

Send the head to 4 piston done.

BoostHatchFreak

Ok well the type r tb is a stock Honda part. But posting anything you can is your best bet but also spendy. Are you limited to a stock ecu ? Or can you tune it ? Anything to get air in and out will always help the camshaft I feel is the best thing to ever do to a ls

JRCivic1

Do they actually CNC a B18/B20 non-vtec yet ???

Dilbones

Exactly-- tryna avoid the "spendy" part

I am unfortunately limited to a stock ECU as well. We can tune fuel pressure and distributor timing. We are not allowed to do cam gears.

I also have a blaster coil ss if that helps.

BoostHatchFreak

well all I know is if I was you id run ( if I could) itr tb, header, and rsx exhaust, port head, go to junk yard and check every non vtec cam I could find get the biggest pair, surface block .010-.015 to get a better quinch and bump compression. don't know what type of racing your into but gearing is always something to look into. get a wideband stock tunning is more then likely a bit rich so you should be ok to increase a bit of air flow and be ok.

Dilbones

Interesting:

• Why RSX exhaust?
• Surfacing block that much wouldn't require adjustable cam gears?
• How lean do you think I can run it at WOT? I am going to be running an AEM and will be going to dyno after doing mods...

I'm into road racing.

BoostHatchFreak

because you seem to have to run stock everything. rsx exhaust and muffler is bigger and flows good. it will retard the cams some which will be a good thing for you as it will/ should move your power band higher and as non v power band is on the lower rpm side it will help out. and the better burn from making a good and tight quench area will be very helpful. that's why earlier I had mentioned welding the chamber up to get the same effect but not change cam timing. also if u want to get crazy with head work buy p8r valves ( aka 38mm vtec size) and valve seats and put in your p75 head. most the time leaner isn't better on non vtec's most the time youll have to go off the dyno. my old b20 didn't like part throttle leaner then 14.2 cruz leaner then 14.9 wot it wanted 12.7-8 id look into a b16 trans forsure then.

Dilbones

hmm and you dyno tuned WOT on your B20?

I have a 4.7 final drive so that helps with acceleration a LOT. The stock 4.2 was a dog.

We can run aftermarket intakes and exhausts. Intake can only be up to throttle body. TB and IM must be stock.

I have a Junk2 exhaust and an eBay intake I cut up to make into a short ram (to avoid hydrolock on tracks with standing water).

BoostHatchFreak

Yes engine was professionally tuned. Get a blox v stack with filter then$80 Get a type r tb it is stock for a b series it’s 2mm bigger (62mm vs 60mm) you want a 4-2-1 header then for tq so I’d get a ebay try y long tube header then there $100 you’ll need a 3 peace test pipe to run it $35 ish