Disaster averted and seeing the light

Discussion in 'Discussion Forum' started by carl, Oct 8, 2018.

  1. carl

    carl True Classic

    Location:
    Virginia
    Ed and I drove up to Summit Point raceway Saturday. Never had the rat X on any kind of long driver (little over an hour to get there) but it ran fine up and back. It was a dreary cloudy day and we hit fog going over the mountains... not great given I have no lights on the rat (just brake lights). I was getting terrible fumes on the car on decel, to the point I had to change my clothes when I got home because they stunk so much. Next day I decided to hook the crankcase vent to the air filter housing. When I popped the top off the sport filter I saw one of the filter base mounting studs laying in the bottom of the filter along with a spacer nut. Why those parts never ending up in the carb is beyond me. And we all know those damn studs pull out of any Weber so easy. Reinstalled the errant stud and spacer trying to figure out how tight is too tight and checked the other three.

    Finally decided to add some lights, the rear is no problem since I have the stock light assembly. For the front I decided to just install two Hella 500 fog lights which will be bolted to the bumper shock mounting tube. The purpose of the lights is more to be seen than to see, I don't plan on driving it at night. I'll post pics when Mr. Amazon brings them to my house.

    Back to the fumes, can our noses tell the difference between exhaust fumes and crank vent fumes?

    Hope to have tags and insurance on the 77X this week, it will feel strange to drive an X with full road equipment.
     
  2. Dan Sarandrea (Phila)

    Dan Sarandrea (Phila) Waitin' On Parts...

    Location:
    Philadelphia, PA
    Virginia does not require lighting on cars to be road legal?
     
  3. carl

    carl True Classic

    Location:
    Virginia
    Well, um, yea, but. I have antique plates which means the car must have everything that came on it functioning properly. But there is no inspection...ever... so I take lawless advantage of that and do whatever I want and yes I could get ticketed if I was pulled over and the officer asked why I didn't use my turnsignals ( I don't have any) or where my lights are (totally gone an a sheet metal plate pop riveted where the headlight doors were.

    So in answer to your question, yes and no.
     
  4. Dr.Jeff

    Dr.Jeff True Classic

    Location:
    Sin City
    Lucky indeed with the hardware not getting sucked into the engine. This may be one case where it is fortunate these engines don't breath well. ;)

    Were the fumes strictly from the case vent? Or could there be another source? Kind of seems like a lot of blow-by if it was only from the breather.

    I'm the same with lights/signals/legal equipment on my old cars; my state has the same option for vintage plates and no inspections, so I abuse the issue liberally.
     
  5. carl

    carl True Classic

    Location:
    Virginia
    Pretty intense on highway decel, top on and windows open so it has to be the breather or exhaust, not a raw gas smell that might come from the sport filter on the carb. Bothers me because I have gone to great effort to seal the fire wall and shifter tunnel.
     
  6. Dr.Jeff

    Dr.Jeff True Classic

    Location:
    Sin City
    Any obvious blow-by coming out of the breather when the engine is accelerated/decelerated sitting still?
     
  7. carl

    carl True Classic

    Location:
    Virginia
    Good question, never checked. I had the breather hose going down to the base of the firewall pointing to the ground. Do those after market catch tanks do any good in this regard? Unfortunately the weather seems to be closing in again so I don't know when I'll have it out again. My turbo muffler based exhaust has the tip running through the rear grill and sticking out about 4" and that's similar to all the guys running quad tip exhausts and I don't think they are complaining of exhaust in the cabin on decal.
     
  8. lookforjoe

    lookforjoe True Classic

    Catch can has to be internally baffled to separate oil particles from vapor. Most are not, so typically they will not alter fume level when VTA vs closed system.

    My exhaust tips protrude about the same, and I don't get fumes except at idle (with windows down). I recently added screens into the TP's to eliminate drone, that restriction caused the exhaust to pool at the rear as I didn't have any fumes prior to that. I can't stand drone anymore, so I'll live with the slight odor. To me, CC vapors have a much nastier 'taste' than regular exhaust.
     
  9. Rupunzell

    Rupunzell Bernice Loui

    Location:
    California
    The M5 carb studs are threaded into the soft metal (might be zinc, might be aluminum) can easily rip out. BTW, if these internal threads rip out, the carb top will need to be removed and thread repair (Helicoil) applied.

    If the studs have come loose, it is likely the internal threads on the carb body are wore out from previous threading cycles. Try cleaning them out with brake cleaner then apply Loctite on the studs then re-install them... with NEW M5 prevailing torque (ny-lock) nuts. Make sure the spacers are in place as they are essential to keeping this joint stay put. Do keep in mind these parts are now decades used and old.

    *Over torquing the M5 fasteners will instantly destroy them... resulting in significant grief.

    Remove the crank case breather hose, cyclonic trap on the block and the flame trap inside the crank case breather hose. Clean them and make sure all is good. It is possible the fumes are due to the crank case breather not functioning properly or aged petro goooo is cooking while driving. Do check for excessive crank case gas from the crank case breather hose with the engine at idle and at higher RPMs. Excessive blow by will result in excessive crank case gas coming out of that crank case breather hose.


    Bernice
     
  10. carl

    carl True Classic

    Location:
    Virginia
    Thanks, Bernice. I think part of the problem with air filter studs is the nylock nuts grab harder than the threads in the carb body and as a result, removing the carb base nuts actually just pulls out the studs, same as if the base was held in by bolts (seen that too). I have seen these converted to the next size up stud which uses a 10mm wrench instead of an 8mm wrench. And of course in the young days of these cars no one was actually removing the air filter base for any reason so the fasteners stayed tight. Hoping for some nice weather so I can take the car out again for an hour or so to see if routing the CC vent to the air filter makes a difference.
     
  11. carl

    carl True Classic

    Location:
    Virginia
    $60 worth of Hella 500 fog lights, installed with a simple L bracket in the bumper shock tubes and we have lights...at least for my purposes. Now the hard part, wiring them and the tail lights.

    IMG_0531[2].JPG IMG_0530[2].JPG

    In case any of you forgot, in an effort to get rid of unnecessary weight, I tossed out ALL of the front light parts, including the housings. 22ga sheet metal riveted into place covers the headlight "holes" in the body.
     
    kmead and ecohen2 like this.
  12. ecohen2

    ecohen2 True Classic

    Location:
    Arlington Va
  13. lookforjoe

    lookforjoe True Classic

    Battery to double throw relay, relay to both lights. Ground off relay through toggle switch in dash, done.
     
  14. carl

    carl True Classic

    Location:
    Virginia
    The instructions say to use the dash switch for signal power but it would be much easier to use the dash switch for ground and just have the wire direct from the battery for both power and the signal circuit...is that what you are saying?
     
  15. Dr.Jeff

    Dr.Jeff True Classic

    Location:
    Sin City
    I agree with what Huss said.
    "Signal power" could also be a ground. Completing the 'switching' circuit can come from either side - pos or neg.
     
  16. Fiataccompli

    Fiataccompli Chris Granju

    Location:
    Knoxville, TN
    did you ever find the source of the fumes?
     
  17. carl

    carl True Classic

    Location:
    Virginia
    no, the last time I drove it, Saturday, was the day I really noticed the fumes, probably because it was a longish drive and the top was on. Then I got distracted with the 77. I will certainly report back when I drive it with the cc hose hooked up to the air filter. If that has no effect, I'll temporarily hook up a turn down tip on the exhaust and see what effect that has. Usually with exhaust fumes my eyes start watering and that wasn't happening.
     
  18. lookforjoe

    lookforjoe True Classic

    Yes. The 30 terminal feed can also jumper & feed 86 (or 85, depending on your preference for ground leg)
     

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