Vacuum Gauge

[HondaBoy]

well, i yanked this off of my vacuum brake bleeder because the rubber pison ring went out and it just doesnt work anymore. anyway, this was just to see if i could get it to work. works well and give pretty acurate readings. anyway, here's some pix. i was going to put it up on the dash somewhere but thought i might was well put it in the console which was a lot easier to route the vacuum line and mount the gauge in. if your wondering, i've had that panel for 3 or 4 years which i made myself.

[shepherd79]

looks good.
nice work.
your vacuum is kind of low. it should be higher.
are you running perf. cam?

[HondaBoy]

no, not yet, but i plan to go with either a colt or delta with new springs and rockers. thats low though? i was told that 19-21 inches of vacuum was healthy, and thats by my auto tech text book. but anyways, cheap mod and lets me know whats up. too bad its not back lit, not possible either on that face. unless i want to go with an expensive one, then maybe so. but that'll wait till i get an a/f gauge. i want the vacuum and a/f gauges in black face, not white, so it matches. i like the black face gauges anyway, just my preference.

[bobafett]

thats about right imo.... i pulled only like 17-19 with a stock cam and extensive headwork rofl. i wish i could see 23 in/Hg, but I only get that much on decel.

[guaynabo89]

Thats about right at idle. I think I get about that maybe 23-24 and sligghtly more on decel like 26-28 I think.

[A20A1]

22-24 is good

I had 8-10 with my regrind and low idle.

[shepherd79]

22-24 is good

I had 8-10 with my regrind and low idle.

damn, now i have to figure out how i am going to keep the vacuum higher for the distributor.
i knew your cam had low vacuum but i didn't realize it was that low.
any idea on how to boost up the vacuum with your cam?

[HondaBoy]

install a vacuum pump off a diesel? would that work?

[MessyHonda]

sorry for the noob question but you are you really measuring? like how much air the carb sucks?

[POS carb]

23 in is pretty damn good, if you have anything less than 20 you should suspect something is wrong (idle mixture, timing, or leaky gaskets/vacuum lines)
I think a vacuum pump would work but that would steal HP, a better alternative would be to lower the tension on the advance mechanism or increase the surface area of the diaphragm with a larger one, or even move the point where it links to give it more mechanical advantage but this would probably be too difficult/custom for the 3gee distributor.

still, 10 in of vacuum will provide a decent ammount of force. Mike, have you been able to check your vacuum advance with a light on such low vacuum?

[bobafett]

brakes start to get funny with that low of vaccum though. 282 cam + headwork = HAHAH you want to slow down? thats too bad!!!

[shepherd79]

well i got mike's old cam. It is Colt wild grind. it is just a little wilder than delta 282 grind.
I had 272 grind and it wasn't enough.
i haven't installed the cam, but if I do have problems with low vacuum i think i may try the vacuum canisters.

[HondaBoy]

hey, on the topic of the cam, i was going to go with a 272 duration, but i've heard some of y'all that really love power go for the 282 duration after having the 272. you know i'm still undecided on the cam i want. but 272 may do just fine with dual weber DCOE 40mm's, thats the set up i want. plus the headwork i want. and i still want to drive it daily. heh.

[shepherd79]

272 will be fine for daily driver. I had it in my car and loved it. It had nice power band and gains were nice too.
I guess with me, it wasn't enough. I want more power. It is like boost, no matter how much boost you have it, you will always want more of it.
i say start with 272 cam drive for a about six month or a year and get 282 cam after that. do the dyno on both cams.
I would love to see the numbers.

[HondaBoy]

i will likely try and get my car on a dyno. dunno if i can right now, but that'd be interesting to see what my carb and exhaust mods have done. definately noticeable difference since i first got the car.