Bypass Valve replacement...any alternatives to the Capristo?

While I repair the clutch fluid leak and with the bumper and muffler now off, I would like to sort the non-functional factory bypass valve on my '96 2.7. It is fixed open, I assume as it either failed or rattled.

Is a replacement Capristo the only choice/best choice? Are there no reconditioning or upgrading kits available to bring the original back to life?

Cheers.

 

The short answer is no.....unless you go to a machine shop and have them press out and replace the bearings. If you search you will find some posts where some members have sourced the bearings/replaced them and the valve worked fine.
Its a lot easier just to go with Capristo but make sure you get the one with the heat shield as there were some heat related failures noted.

 

You mention that the valve is fixed 'open' (is it wired open? or seized). Sometimes if the valve is still functional but just starting to rattle you can adjust the nut on the shaft...add a little preload adjustment.
Sometimes this is enough to stop the rattle......not sure for how long though.

 

Anyone have any information on the bearings? I'm not finding anything on a search relating to the bypass and replacing the bearings. Just the ones about tightening the shaft. I have access to a press and am getting real sick of the rattle. I tried the adjustments with the shaft to tighten things up with no success. Also waiting on Goth to develop a reasonably priced replacement for the OEM (Hint, Hint).

 

I am not sure as of yet. One way or another I think the best long term solution is the Capristo. My wish is for the car to work right, the way was intended to.

Thanks all for the feedback.

 

Is the heat shield the nicely finished metal outer casing of the vacuum chamber?

 

I used one recommended on here and sold on ebay. It needed a bit of sorting to form a gas tight fit but not a major job and so much cheaper. I'll have a search around for that thread.

 

no, its an extra heat shield below the vacuum chamber

 

& if you can find the ebay listing....pls post the link

 

http://www.ferrarichat.com/forum/348-355-sponsored-bradan/391007-bypass-valve-has-balls.html

 

IMO it's not the "balls". I believe that the rattling sound is the butterfly flap rattling against the interior housing. The reason is that pre-load (from the vacuum valve) on the flap decreases over time. My solution is NOT increase pre-load by lengthening the shaft coming from the vacuum valve; it only works temporarily. Instead I believe in slightly SHORTENING the shaft so the valve is slightly open at rest and therefor does not rattle against the housing. But, to each his own!

 

eBay listing

Ferrari 355 F355 F50 Exhaust Bypass Valve with Titanium O Rings Seals | eBay

 

I would not replace it unless it is actually rattling...and if it is, then try the adjustment of the rod, that got rid of the rattle for me. I had another rattle later, that I could not find, on a hunch, tried the Capristo valve. It did not fix the rattle, it ended up being a baffle internal to my stock muffler. A Capristo muffler took care of that. The Capristo valve is nicely constructed though.

 

Adjusting the rod is not recommended, if you tighten the rod, the valve will not open.

 

Hello Hugh,

I cannot guarantee that amongst the myriad of vibrations and buzzes emanating from behind me that the valve is indeed one of them. I don't think so though. It is my understanding that it rattles when it is closed so if that is the case I won't know until it is functional, if in fact it can be made functional again.

I will pull it apart and find out its reason for seizure. If it can't be restored then I will order the Capristo.

 

Keep searching.
there's threads on the bearings, replacing the diaphragm, and a Porsche valve alternative.

 

That was not the case for me, or a couple other local 355 owners. Only two or three turns adds enough force to prevent rattling. I suppose if one gets carried away then that could result in an issue...but then just back it off a tad.

 

Once I've got it back together I will see if needs some minor adjusting as described. Just enough to create a small amount of tension.

 

Not entirely a drop-in replacement but is very close. Typically you will need to notch the rear passenger side of the bypass valve frame to clear the lip of the factory (or even Tubi) muffler. Just search ebay for "exhaust control valve" and you will have many to choose from. Look for a 2.5" normally closed valve to mirror the factory operation (however Capristo is normally open I think). Good luck.

Requires modification:
Stainless Steel Exhaust Control Valve Set Vacuum Actuator 2 1 2" 63mm Pipe Close | eBay

May not require modification:
Exhaust Vacuum Valve with Vacuum Actuator 64mm 2 5" Closed Baffle | eBay

 

If there are any questions about our product please do not hesitate to call or email. Thank you for the interest.

All contact info is below.

Thank you
Erik Krammer

 

wasnt there a member on here that rebuilt them? I cant remember his name because mine didnt need rebuilt so I just skimmed the thread

 

Anyone know anything about this second one? Valve comes from Cyprus so I would be very leery of sending them $300.

 

Last I knew Jim Enterprises in China or Taiwan (they build the Fabspeed headers) sells one also I'm not sure on cost...

 

In addition to the valve though, $300 today buys you like 1/16 of the country as well. So go get 15 friends and you can own all the bypass valves. Just sayin.

 

I tried the first one works fine

Never tried the second, pay with payapl, no issues if any problems

I buy worldwide daily and usually better then buying here in the states, I get my Bosch stuff from Romania in like 3 days. faster then my Bosch Distributer