wow
Krowbar, I have never read something so kooky in my life "it gets what it gets". Your technical knowledge is simply amazing. My Questioning of Kermit was based solely on his statement (above) where he claimed that he could add this device in a car that was producing only 10" of vacuum at idle and then he had brakes even at idle from that point on. The Brake Booster requires 16" to operate that is simply a fact and as I said even if this device opens with less vacuum it still cannot produce the missing 6" at idle (stop and go traffic) that you would need to operate the booster. I run a stock booster with a fixed vacuum gauge to monitor vacuum. I never said the device does not work I took issue (see below) only with the sales pitch that he got the brake booster to work at idle with only 10" of vacuum as it is impossible.....and still is. It was a BS story. Yes I understand that deceleration will give you increased vacuum but in stop and go traffic you only get idle vacuum and 10" will not do it when it comes to your booster. If you are going to attck me then at least stick to the facts and try not to imply that I ever said the device does not work. I said it will not increase vacuum that does not exist from the source (engine). You story is so heart warming and I am oh so touched by it but really save that stuff for those that care about your feminine side......and now you are attacking the 4 liter post here? You are doing what you excuse me of.
My God man, how many posts have to be written to explain something my 8 year old daughter can understand. If I have a vacuum source of 10 inches of mercury, and at the end of a hose connected to that source, I have a check valve that requires 5 inches of mercury to open, and that on the other side of that valve is a chamber vessel with a guage, I will only have a pressure in excess of the opening pressure of the valve, or in this case a negative pressure. If it takes 5 inches of mercury to open the check valve on a 308 that only produces 10 inches of mercury, the most I will ever get the booster down to will be 5 inches of mercury. 10 - 5 = 5. or, 2nd grade math. If we replace that valve with one that works at .05 inches of mercury, we will have (10 - .05) 9.95 inches of mercury in the booster. As Kermit seems to be a backyard kind of guy, and as his part seems to work better than a stock valve, who cares if he explains how it works? I havnt yet seen and technical details of how boring out the main webs of a 308 block to increase it to 4.0 liters wont weaken the block, and I dont hear anyone running that company up one side over it. But both a stock engine, and especially one with bigger cams, have pulses in the intake manifold of greater and lesser pressure. 10 inches is a average, but if you watch a guage you may see the needle flicker as high as 12 or 14. If the check valve is sensitive enough it may be able to get the line pressure down close to that higher reading, at that will be available in the booster. As far as my kooky reasoning, or technical knowledge, people have been "camming" up engines of all makes and dealing with lower manifold pressure for decades. Brake boosters are simple vacuum chambers and as they are generally supplied with only engine vacuum, enthusiasts have dealt with that as well for just as long. I do not recall any of the Muscle cars I grew up with that we "cammed" up, having any real trouble with less braking power, but they kinda sucked at stopping anyway. You deal with it. Or in your case you installed a pump. Diesels suffer from almost no manifold pressure at all and "REQUIRE" a vacuum pump. But the booster doesnt "need" 16", although it may be rated at that figure. It may not work as well with less, but it will still provide boost. The point here is that the Ferrari seems to have a piss poor check valve, and Kermit "may" have created a better valve. Let the testing begin.
The minium inches of vacuum needed to operate the 308 vacuum booster is 15.5". The Ferrari Boxer was unable to produce that minium amount so they added a vacuum pump to run the booster. Minium means the amount to operate the booster not the check valve. because you have enough to open the check valve does not mean the booster will work...and it wouldn't unless the booster actually see's 15.5" of useable vacuum. "USEABLE VACUUM" Stop misleading people. Your post is pure technical double speak (nonsense) and your attack on the 4 liter project in the post before shows your motivation. The valve by the way was not delevloped by Kermit but by ET Performance for Harley's. The only aux electric vacuum pump that I have found avalible (and installed in my 308) is made by Stainless Steel Brake Company (Sold by summit and jegs) it produces 27" of vacuum, it's controller starts the pump when vacuum falls to 20"'s of vacuum thereby always maintaing the 16"inches required. I run cams that have in excess of 400 lift and max vacuum even at decleration was less then 16". You have no 1st hand knowledge of Brake Booster requirements on a 308 and just wish to falsely attack as cheerleaders do.
Does a brake booster in a 308 somehow work mysteriously different than it does on any other car in the world? Will the brakes still stop the car (albeit with increased effort) if the engine stops running or there is an otherwise loss of vacuum? Of course they will stop the car. Its a booster, and thats all it is, and how much boost you get is related to the pressure differential. It doesnt magically stop working just because the pressure is reduced, it just has less "assist" in the effort required to apply the brakes. I can be sure that even at a measily 5 or 10 inches of manifold pressure the booster is "assisting" the effort, its just not assisting with full capacity. So deal with it. But thats not really the problem. The problem is your unchecked anger with Kermit and trying to start some BS everytime someone mentions anything about him or his products or his ideas. Kermit didnt start this thread, and your only input thus far is to use yet another thread to funnel your hatred and anger of Kermit at the rest of us, and to use Fchat as your sounding board. Personally I am rather tired of it. I have never met Kermit, and have only briefly spoke to him. And I really dont think anyone here wants to hear it rehashed everytime you have PMS. Perhaps in the future you could try to either remain silent or offer some usefull information. The sooner you stop trying to keep your pissing contest going the happier all of us will be. I didnt think this Forum was to be used for someones personal vendetta.
[size=+1]OK guys, as one of the moderators of this forum, let me urge you to stay ON ISSUE and not get personal.[/size]
but, I don't run a booster on my 308 (which develops about 2 - 4 inches of vacuum at idle). If you are unhappy with the booster assist after a couple of attempts, Paul, a significant change to the mechanical leverage can be achieved by altering the bell crank (cut and weld) and/or the pedal. FYI, the stock leverage ratio is about 2.7:1. Mine is now closer to 6:1. I do run differently sized MCs. Philip
Where the heck is this brake valve located on a carburetor car? I can't locate mine in either the upper or lower location... Kermit said near the #4 cylinder, but I don't see it there.... Pix anyone? Greg 1977 308 GTB USA
Greg, The check valve is in a hose coming off of the left rear intake manifold, looking at it from the back. Depending on how fastidious you are, this could only be visable as a small dirty lump in the midle of the hose that disappears into the left rear wheel well. No offense intended. Anyway, once you yank that filthy old chunk of aluminum out of there and stuff in one of Kermits little gizmos, I think you will be pleased, not stupified or overwhelmed, but pleased with the noticeable reduction on pedal effort. All the Best, chris
RESURRECTION I'm resurrecting this old thread because the stock check valves are definitely No Longer Available (NLA)... and someone asked me about this. So if anyone wants to try the style discussed here that had been sold by Durable One, you can find it at http://www.et-performance.com/brake.html No flames... please don't shoot the messenger!
Part number please? edit: I think I found it... and it's less than $10?!? p/n 193186 - I don't know if it will fit with the stock vacuum hose, but check it here: http://www.ricambiamerica.com/parts_catalogs.php?V=diag&I=596 and http://www.ricambiamerica.com/product_info.php?products_id=210005 It's also used on the 430, Challenge Stradale and 575! Or the 355/512TR/360 version (p/n 147978) here for $25 http://www.ricambiamerica.com/product_info.php?products_id=200868 Either way, whichever will fit might be the solution! But unfortunately, no close up pictures.
Daniel Pass has now added a close-up photo to the Ricambi website at http://www.ricambiamerica.com/product_info.php?products_id=210005 He told me it has 12mm fittings. I'm not at home right now so I can't compare that to the original valve... someone go out and measure to see if this will fit in the original hoses properly?
The 308, 328 and BB use a 12mm hose, so this check valve should do the trick. Actually, I'm 99% sure that this is the same valve that's used on a vintage BMW 2002, as I'm doing a full mechanical resoration on one right now. David
I just purchased a check valve the fits perfectly from AutoAnything, prt # 34 33 1 151 532, or W0133-1637053, fits a mid-80's BMW 5 series. About $15. Don't clean a check valve with a spray cleaner if it has any rubber parts in it. I did that and the rubber dissolved.
