Silky_Johnson Posted February 20, 2013 Report Share Posted February 20, 2013 Tap 2 holes into IM.....run metal lines if need be You may need to tap four holes if this is the Cannon manifold that I'm thinking of??? The main thing is to get the PCV venting evenly to each runner. As Stoffregen pointed out, running a PCV to the manifold will change the mixture somewhat (although I never noticed much of a change with my tuning), and you want the mixture to be the same on all four cylinders. Quote Link to comment
AZhitman Posted February 20, 2013 Author Report Share Posted February 20, 2013 It's this manifold: Quote Link to comment
Silky_Johnson Posted February 20, 2013 Report Share Posted February 20, 2013 It's this manifold: My guess is everyone can see this picture but me? It just says blah blah numbers.jpg on mine. No matter. Quote Link to comment
AZhitman Posted February 21, 2013 Author Report Share Posted February 21, 2013 Hey Silky... it's the same pic as I posted on Page 2 - Might show up there. Thanks man! Quote Link to comment
73DATSON Posted February 21, 2013 Report Share Posted February 21, 2013 Why not just connect valve cover to a tee with the crank then tap into the down pipe? Is this a good ideal?? Cause that's what I did and I have no vapors:-)) Quote Link to comment
AZhitman Posted February 25, 2013 Author Report Share Posted February 25, 2013 I've got a header, but I don't know why it wouldn't work... Quote Link to comment
73DATSON Posted February 25, 2013 Report Share Posted February 25, 2013 I've been driving my car for about one wk with the valve tee to the crank then to my down pipe, no vapor smell?? Don't know if this a good ideal??? Someone can tell if its ok??? Quote Link to comment
K_trip Posted February 25, 2013 Report Share Posted February 25, 2013 - removed - Quote Link to comment
EricJB Posted February 26, 2013 Report Share Posted February 26, 2013 I've been driving my car for about one wk with the valve tee to the crank then to my down pipe, no vapor smell?? Don't know if this a good ideal??? Someone can tell if its ok??? When you say downpipe, you mean exhaust, right? Did you stick your finger over it to check if it was sucking? If so you must have a really open exhaust. Put a check valve on it to be safe. Quote Link to comment
73DATSON Posted February 27, 2013 Report Share Posted February 27, 2013 Personally ... I would not want to use a "down pipe" or "road tube" as my only crankcase vent. I would want my crankcase connected to a PCV that's connected to the intake, for positive ventilation. Plus the valve cover vent connected to the air filter, for the bi-directional venting to be filtered and any possible oil smell collected and burned away. That's what I suggest for a street motor, since you were asking. Thx Quote Link to comment
Stoffregen Motorsports Posted February 27, 2013 Report Share Posted February 27, 2013 It's this manifold: If that is the manifold, you could probably cross dril the big round aluminum boss that connects the front mounting face of the manifold. That area just under the linkage rod. I have done this on motors not using PCV for more even idle, but if you did use a PCV valve, this would help a lot with the tuning/mixture problem. There are drill bits available, at places like home depot, that are 8-10 inches long. Drill it 1/4" or 5/16" and just plug the outer holes with pipe plugs, or drill the outer most hole larger and run the PCV there. Confused? Quote Link to comment
Stoffregen Motorsports Posted February 27, 2013 Report Share Posted February 27, 2013 Also...ditch that linkage. Centerpull linkage is easier to keep in tune and there is less danger of a twisted throttle shaft. Quote Link to comment
AZhitman Posted February 28, 2013 Author Report Share Posted February 28, 2013 Thanks. Not totally confused. Are you saying drill the center boss perpendicular, or at each end? Seems to me, if it connects all four runners, I could tap the very center of it, insert a small threaded nipple, and that would supply enough vacuum for my PCV (or am I reading your post totally wrong?) That's not my linkage, by the way. The setup I'm using is much more beefy, and no danger of twisting this throttle shaft. Quote Link to comment
Stoffregen Motorsports Posted February 28, 2013 Report Share Posted February 28, 2013 Not totally confused. Are you saying drill the center boss perpendicular, or at each end? Seems to me, if it connects all four runners, I could tap the very center of it, insert a small threaded nipple, and that would supply enough vacuum for my PCV (or am I reading your post totally wrong?) Yes, you got it. Drill as shown below. Now it may be a real pain in the ass to keep the bit centered, but I have done it. Just drill slowly to keep the deflection down to a minimum. And you may need to drill from either side if the bit is not long enough. Quote Link to comment
oldskoolvws Posted March 1, 2013 Report Share Posted March 1, 2013 That's gotta be a 3/8" x 12" bit yes? Home Depot has them. If your not confident, any competent machine shop could do this easy. Quote Link to comment
Stoffregen Motorsports Posted March 1, 2013 Report Share Posted March 1, 2013 That's gotta be a 3/8" x 12" bit yes? Home Depot has them. If your not confident, any competent machine shop could do this easy. I would go as large as possible, but 1/4" or 5/16" ought to do it. it is not for flow, just balance. Quote Link to comment
Silky_Johnson Posted March 1, 2013 Report Share Posted March 1, 2013 I am probably way out of my league here... ...but this drilling idea seems weird to me. Is the plan to drill through and only have one outlet on the side? Here's my beef. It is my understanding that you want to keep the mixture even on all four runners, and the PCV will lean out the mixture slightly. So, you want the PCV/crankcase fumes distributed evenly to each runner so as to "lean out" each runner the same amount. Let's say that you drill from the No. 4 runner through the big aluminum boss to the No. 1 runner. The only exterior hole would be on the firewall side of the manifold. Then you get it rigged up so the PCV enters from the No. 4 side. The No. 4 runner sucks in fumes from the crank case, and those fumes mix with the fuel mixture in the No. 4 runner leaning it out slightly. From there, the No. 3 runner is going to suck in some of the mixture from the No. 4 runner, right? It won't be pure PCV fumes like the No. 4 runner. It will be mixed with fuel mixture, so it will not lean out as much as the No. 4 runner, unless I'm mistaken. No. 2 will be pulling in a richer mixture from No. 3, and No. 1 will be richer yet. For this reason, it would seem that you would want the distribution of PCV gases to be external so that all runners are receiving only pure PCV fumes. If I am way off, someone correct me. I just could get this cross drilling idea to make much sense in my head. And for the record, I seriously doubt the PCV leans the mixture very much at all -- not noticeably anyway. The cross drilling would probably be functional, but I don't think it would distribute the PCV fumes evenly. Quote Link to comment
Stoffregen Motorsports Posted March 1, 2013 Report Share Posted March 1, 2013 Me personally, I wouldn't run a PCV at all, but if you do then why not share that PCV induced vacuum leak with all the other cylinders. It wouldn't matter so much where you put the PCV, but if I had my choice, I'd put it in the balance bar, between the carbs. And the cross drilling isn't just for PCV, it can help smooth out the idle, period. So PCV or not, cross drilling can help, but I will admit, the gain is negligible. But then this whole forum is really about splitting hairs. Fram vs Other, spray bar or not, etc. Splitting hairs is how you obtain a maximized state of tune. And it might fail sometimes, but then nothing ventured, nothing gained...right? Quote Link to comment
Stoffregen Motorsports Posted March 1, 2013 Report Share Posted March 1, 2013 BTW- They peed on your rug Dude. Quote Link to comment
Silky_Johnson Posted March 1, 2013 Report Share Posted March 1, 2013 BTW- They peed on your rug Dude. It really tied the room together too. Quote Link to comment
EricJB Posted March 2, 2013 Report Share Posted March 2, 2013 It really tied the room together too. Donnie, STFU. Your like a child that walks in the room in the middle of a conversation. Quote Link to comment
Sealik Posted March 2, 2013 Report Share Posted March 2, 2013 I would cross drill from each end/side of IM....and not go through the 2nd runner into the middle bar. Cap the 2 holes just drilled Then.....drill 2 holes into that 'bar' from the top between 3 and 4....1 and 2 ....Fittings and hose to a tee in the center......<.....PVC... (Inserts question mark) Quote Link to comment
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