m4xwellmurd3r

Whats the compression work out to with tge head shaved?

Frankacura

I M4x
The B20 P8R is a 9.2:1CR pistons but cuz of the head bore it lowered the CR to 8.8:1
PHK pistons, shave the head and bloc bring it back around 10.4:1CR
The Dyno sheet is only 3 pass to find out the power i had from my street tune.
then i removed the exhaust for streingt line 3' and my AFR went from 12.7:1 to 13.4:1
so guess my Whp now...

m4xwellmurd3r

Nice. Seems like I should be in the 200whp+ range with my ported pr4 and jge303 cams. Would be nice to be able to run my itbs too. Theyre cbr1000rr so 44mm. Capable of around 200hp

blackeg

so i picked up some 403's, stock camgears, and an aftermarket dual valvespring set and some oem retainers off ebay for 240 bucks total. parts look decent and useable, im going to slap it together while im off work and snowed in with this blizzard the next few days.

i dont know the brand of the springs though. they seem to have a tiny bit more pressue than a oem vtec spring, but less than my vtec supertechs.

they are also 1.61" tall and i think the oe spring was 1.74" uncompressed height. anyone have an idea what brand they may be? id like to say crowers and they were bought with the cams....

think i should be worried about shimming the exhausts or anything, or just run them as long as the keepers go in fine and still have pressure on them...

spAdam

iTrader: (1)

Good deal. Any chance you can get the springs tested for rates and compare that to Crower's rates? Or maybe at least shoot Crower a line and see what their requirements are for springs.

blackeg

i could get them tested but it wouldnt be for a few days at least and im about to be snowed in for a while i was planning on drinking coffee and huffing kerosene heater fumes in my garage while i throw it together... i know the 403's dont need much seat pressure it seems many people run them with oem dual vtec intake springs, just shimmed up on the exhaust side a bit.


ill probably get them measured

spAdam

iTrader: (1)

Well, this happened:



Picked up from a local member last night. They look basically new. I need to find some springs first though.

Looking at the card, it looks like stock vtec springs are just a hair on the light side for these, but I'm interested to read up a little more in them since I have a set or two floating around the garage.

They won't go in for a little while, I need gears and a degree wheel first and will most likely hold off until timing belt time anyway.

Btw, here's the cam card from Crower:

http://www.crower.com/searchresults/

And a good collection of spring data from DDTech:

http://www.ddtechcams.com/technical-information/

blackeg

lol pickin up 403s randomly is contagious!

I was poking around on crowers website I think the aftermarket duals were 48 lbs on the seat with an optional 70 lb optional . I think the rocket single springs qork well too

spAdam

iTrader: (1)

Doing some quick calcs, Rocket Type 2 look like the way to go. Not sure what their tested seat height is, but their open pressures are 161/157 at .422/.411 lift.

Frankacura

i dont know where you get that tricky of Vtec inserts.. But this is what im doing also.
on my friend B18a Crower 403 i installed only the RED INTAKE springs doubled by Vtec inserts and i told him 7800rpm will be safe... But this is where he shift to run his best so i raise the cut off to 8000rpm and his ET went down, do i raise it again at 8200 but told him... Juste try to dont hit cut off,
A week after he call me and told me. Frank your springs are really good
then i ask why and he told me...
i push the throttle wit my hand and cable went off and jam the RPM in Cut Off till i shut the key Off 8200RPM constant for 5sec LOLOLOL
Crower ask for 160 psi springs rate.. but you dont need that
The Intake NonVtec spring offer 90psi against most exhaust springs that max out 70-80
B18b and B20Z Canadian offer good exhaust springs 100 psi.
There is many différents springs (Rate and coil bend) on exhaust side for the B
but only One Red spring for Intake. Add of a vtec insert will get you about 125Psi Total
and b16a/GSR intake springs are about the same... 130psi
Type R 155Psi
My Toda B Springs 180
Junk2 Pro springs 240psi ( worn your rockers, stretch T/Belt) lol
and yess exhaust guide have a lower floor by 2mm


This is the shim i use Under the seat locator

Frankacura

By the way... Never use H22 springs to double your B springs
Intake H22 springs can be use, but exhaust will coil bend at 10mm on your B exhaust side

spAdam

iTrader: (1)

Which all makes great sense if you think about it for a second.

- ITR cams are about the same gross lift as the 403s.
- Redline is about the same.
- Valve masses should be damn near identical mass (for a P8R head at least).

This is definitely simplifying the system, but these three factors are the main ones in picking a valve spring rate. On paper, the vtec springs should do the job. The interesting thing is that Crower's recommended springs do not meet the requirements, corrected for lift, on the 403 cam card.

I started putting together a spreadsheet yesterday to compare different springs that are on my list of possibilities.

blackeg

i am going to stop by my machine shop in the next few days and have him measure the rate on the dual springs that came with my 403s which im assuming to be crowers. they have a installed height of 1.4" and should have 48lbs on the seat. at the same time im going to pick up the oem b16 springs from a vtec head i have there getting worked over.

frank, where did you order those shims from? what otherwise would you recommend using to shim up under the valve spring seat?

Frankacura

Type R cams are more as 404's cams about same lift. but R cams are 240 degree at .05 and 404 make 226 or so.
Crower 403 dos'nt have lot of lift and this is why you can use vtec inserts from B16a in intake... and exhaust. but i would remesure all that to run b16a inserts on 404's cams , to me they dont fit.
Non vtec valves are heavier, but nonvtec head dont have to lift 3 rockers

Frankacura

Just use the insert springs from the intake B16a springs. so you need 2 head to make a set

I buy the shim in a speed shop in my area. there is a number on it.... V.S.I.300
it fit the size and tickness. VSI #300....1.125 OD x .717 ID.
they are solid brass made, so i guess anyting that fit in the head hole seat locator and around the valve guide will be ok. just dont use soft aluminium or someting like that.

spAdam

iTrader: (1)

Your machine shop should be able to get them for you too. I need to dig around in my stuff today and see if I can find my old b16 springs.

blackeg

good stuff guys. i was wandering around home depot and lowes with the dial calipers yesterday looking at washers. i found some with the proper thickness and inner diameter to locate themselves on the guide. only issue is outer diameter they are a tiny bit smaller than the valve seat by maybe .5mm just where the outer spring would sit. not sure if i want that maybe it will mushroom the seat and sink the outer spring....

ill ask the machine shop when i go next week.

im also in the process of modifying a p30 im and pr4 head. i found some 3/4 inch hollow aluminum stock. im going to see if i can get a friend to tig it to the head as a nipple that i can slip the coolant hose over. trying to avoid the jb weld if possible this go around. there really isnt a lot of room between that port and the manifold where it was cut so i made the nipple pretty long and may have to weld it in there at a bit of an angle.


good idea on tapping that oil journal for the middle stud. it was already at a perfect diameter i threaded and slipped a 8x1.25 helicoil in there and it will get a stud. im likely to put some liquid gasket on there to make sure it doesnt leak oil

darnizzle8805

iTrader: (1)

Tap the coolant port, install a threaded barb fitting, use pipe dope to seal. I've never had a problem, and no leaks when installing my PR3 and P73 manifolds.

solorex

I have been meaning to post these up for a while now, couple of dyno plots of my B20Z. Just shows the potential of the non-vtecs! The internals are 100% stock, untouched except for the ARP rod bolts.

Baseline Dyno:

Stock low mileage B20Z
ARP Rod Bolts
LS Intake Manifold (port matched to TB)
68mm professional products TB
Custom 4" to 2.5" short ram intake
stock '91 CRX Si injectors
stock fuel pump
stock super restrictive CRV manifold
2" exhaust

Second Dyno only changes are:

Crower 403 cams
Crower valvetrain
RSR 4-2-1 Header with 2.5" collector

Engine is mated to a S1 short ratio tranny. I have to say I was pretty impressed by the gains with the 403 cams. Keep in mind the head and bottom end are completely stock (with the exception of the rod bolts). I was also impressed by the gains we had tuning on the S300!

spAdam

iTrader: (1)

Nice numbers!

blackeg

certainly nice numbers! what was done between the 2 lines on the 403 graph? just tuning or cam gear adjustments as well?

few questions, which you dont have to share if you dont want

about what afr and ignition did you wind up settling on using at wot after the tune?

what muffler did you have on there that was 2".

i bet that thing is amazing fun in a crx!

solorex

Just tuning, the graph shows the first pull vs the last pull after tuning. I am running stock cam gears so no cam timing changes. I used the non vtec crower 403 calibration that comes with the S300, but tidied up the fuel a bunch. It's actually a pretty ugly map up top. Can't remember if we changed the ignition timing much, I don't think we did.

I don't have a plot of the a/f ratio, but we were in the 12:1 range at WOT.

Yeah it pulls hard in my CRX, and honestly has made me procrastinate building my B20Vtec back up again. This is a dead reliable setup and is more than fast enough for autox competition, but I did like the high end of the B20Vtec out on the track.

The muffler is made by Scorpion out of the UK. Large oval can single in dual out, straight through. Could I get some more HP with a 2.5" exhaust, probably could but I love the sound of the 2" and it doesn't seem to be hurting performance that much.

Frankacura

Nice comparo solorex
If you have the chance to slam an P30 IM on it you will probab like the torque band, it will raise the peak Tq rpm and Hp may not drop that much pass 6500rpm.
It will rev 8000rpm, you have too much torque on that b18b intake and the runners curve are hurting your top end.

solorex

^thanks and agreed a p30 intake will likely help for sure, the power is dropping off up high.

spAdam

iTrader: (1)

I finally found my P2T (B16A2) manifold. Should have it sometime next week.