vaccum assist brake & cam

[ronald55555]

after i installed my crower stage 2 cam, sometimes my brake would have almost no power assist because of the vaccum at idle. happens at low rpm like when i'm parking, or even when i coast then hit the brake. any solution?

[cbuscivictuner]

Jegs and Summit make 30 dollar vaccum reserve canister kits for domestics that run big cam's and power brakes so im sure you could figure a way to rig the kit up.I would also make sure 100% that is the problem first.

[Jcazz]

no other known problems that ive herd on here in regards to your problem running a Stage 2 crower cam....

Can someone help him? Bumpy!

[dragman99]

after i installed my crower stage 2 cam, sometimes my brake would have almost no power assist because of the vaccum at idle. happens at low rpm like when i'm parking, or even when i coast then hit the brake. any solution?

valve lash is probably too tight.

[rushi]

I have Crower stage 3 cam, ITBs and idle(1000...1100rpm) MAP of 35kPa. Not a single problem with brake booster or anything. It's definately not a cam problem for you. Too tight valve lash would make engine run really crappy, or not run at all. Sure you don't have any leak, and one-way valve at brake booster hose is ok?

Vacuum canisters etc are BS for these things.

[transzex]

after i installed my crower stage 2 cam, sometimes my brake would have almost no power assist because of the vaccum at idle. happens at low rpm like when i'm parking, or even when i coast then hit the brake. any solution?

Cam timing correct?

Retarded cam = lower vacuum.

I've drove a Crower Stage 3 97 EX Coupe with tight lash settings and no vacuum/brake problems.

[ronald55555]

the vac gauge reads about 10inhg most of the time at idle. 1 thing i didnt mention that i probably should have; the car is auto, so even though the idle is at about 900/1000 in neutral, the tranny will hold it at ~750 in drive. The car drives ok otherwise, considering it's not tuned, rich everywhere, low power <4k rpm. The cam timing should be ok, i didnt take off the belt when changing the cam, i just marked it at the cam pulley, unless the belt somehow skipped a tooth at the crank while the tensioner was loosened. I guess i'll check tomorrow.

anyone with a vac gauge can tell me what yours read at idle?

[SOHC_Rules]

ALWAYS at least slip the belt off, and when putting it back on, ALWAYS realign cam and crank sprockets, then put belt on

[marcin]

z6, zc pistons, crower 3 cam, ITB's
17inches @ 900rpm

[AMkrew_1]

10 inches of mercury is way too low. I'd bet on lash setting is too tight as well. If not, there is definately something else wrong...

-josh-

[transzex]

nonVTEC D15B7 with big Crane cam (no wimpy VTEC lobes to help the idle)

would idle at 12" of vacuum, not happy about it either......

What engine and cam part number you running?

I'm guessing 1/2 tooth retard, maybe a full tooth if it slipped at the crank pulley.

[ronald55555]

didnt get a chance to check it out today due to the snow we're getting here. but looks like timing could be the problem. Maybe thats why i'm running so rich across the board.

It's a y7/y8 minime, crower stage 2 y8 cam, oem y8 cam pulley. I'm absolutely certain these are y8 parts and not z6. 10in is just a guess though, havent driven the car for a while, i didnt really pay attention to the vac gauge before since it was in my glove box. i'll check it out once the snow starts melting this weenkend and i have a chance to drive the car.

What kind of setup are you running transzex? link? I just got an eg for a winter beater and it has a b7 in it, wouldnt mind spending a bit of money on the engine, would be way cheaper than my ek, since the eg is already manual and obd1. and no vtec too, cheap camshaft.

[transzex]

put a 92-95 cam gear on there and be done.

I'm guessing 1/2 tooth retard

:mikej:

[dragman99]

idk man. i've had my cam set many different ways and never had problems with the braking.

i also think that an internal vacuum leak such as a rocker being too tight can cause the brake problem and the rich condition.

[Eyal 951]

also check for vacuum leaks, back check valve, bad brake booster etc. I'm running stage 2, along with S2 manifold etc, and even trying to pump the brakes, i never loose vacuum.

[ronald55555]

i'm almost certain the valve lash isnt too tight, i set them pretty conservatively, if anything they might be a tad loose. But i used some old cheapo feeler gauge, i'll get another set and do it again.

[dragman99]

i'm almost certain the valve lash isnt too tight, i set them pretty conservatively, if anything they might be a tad loose. But i used some old cheapo feeler gauge, i'll get another set and do it again.

you might as well anyway. it's a good tech tip to go back after about 500 miles and check them again after a cam install. i'm not trying to say that you don't know what you're doing, but using feelers can take some time to used to as well. i don't know your experience but i know it took me 5-7 times before i figured out that you don't push the feeler as hard as you can between the valve retainer and rocker. first couple of times i ended up with them way too tight b/c i was actually pushing the valve open. had marks all over my finger from where they dug into it. ya know, noob shit like that.

also, i like the set of go, no go feelers i have now. makes it a lot easier.

[ronald55555]

put a 92-95 cam gear on there and be done.



:mikej:


I though the y7/y8 cam gear is the right gear for my setup, everything should point up at tdc, no?
how do you guys check cam timing? I stick my dip stick into cylinder #1 through the spark plug hole, crank it til it's at the top, and thats my tdc for the bottom end. Then look at the "UP" mark on the cam pulley and make sure it's at the top. Is this the right way?

[dragman99]

I though the y7/y8 cam gear is the right gear for my setup, everything should point up at tdc, no?
how do you guys check cam timing? I stick my dip stick into cylinder #1 through the spark plug hole, crank it til it's at the top, and thats my tdc for the bottom end. Then look at the "UP" mark on the cam pulley and make sure it's at the top. Is this the right way?

there's also marks on the bottom pulley. the white mark on the crank pulley, and there is a pointer on the lower timing cover. checking it with the dip stick is alright for a v8, but not a honda. another good way to check it to by checking the ignition timing. if the most you can get out of it with the dizzy advanced all the way is 15-16btdc, then the cam is retarded about half a tooth. if the least you can get out of it with the dizzy reatrded all the way is 15-16btdc, then advance a half tooth.

also, it's possible that you got a cam meant for a z6. the only difference is the position of the keyway. hence the possible half tooth difference.

[transzex]

Y8 cam = 1/2 tooth off
D15 = 1/2 tooth off

1/2 - 1/2 = zero, use the 88-95 cam gear

[ronald55555]

Y8 cam = 1/2 tooth off
D15 = 1/2 tooth off

1/2 - 1/2 = zero, use the 88-95 cam gear



really!? but i have a y8 cam, y8 head and y7 block. i though z6 is the oddball.

[dragman99]

looks like someone else has the same problem.

http://www.d-series.org/forums/showthread.php?t=56219

[ronald55555]

yea, mine sucks below 4k too, but his sounds worse. But the weird thing about my car is, the a/f is ok at lower rpm(considering it's not tuned), around 12.3-13.0 below 4k, then it gets really rich around 5k, 11.x, then leans out a tad before redline.

cant wait to work on my car, if only the damn snow would melt.

[transzex]

I just read, I guess I thought marcins post of "Z6....." and I thought you had a Z6 build.

Still 10" vac @ 900 is way low, but your AF's are dead on for not being tuned.

Did you check you ignition timing after installing the cam? Was it different than from the stock cam? IN Theory with all Y7/Y8 parts the ignition base timing shouldn't have changed. IF it did something is not quite right.

If Honda would have just either used the same cam gear and changed the cam index points between 1.5 and 1.6 motors, or used the same cam index and two different cam gears, stamped 1.5 and 1.6 as needed. But no they had to go and mix the parts up and create a headache!

[ronald55555]

I did change the ignition timing a bit, but the position of the dizzy is still normal, towards the firewall a bit more than before, but still not nearly maxed out. If my cam gear is off by a tooth, the dizzy would be all the way advanced or retarded just to achieve stock timing right?