| Author | Message | ||
| Steve Magnusson (91tr)
Member Username: 91tr Post Number: 563 Registered: 1-2001 |
Richelson -- On your '78 the maximum protection would be to put one filter in the top line from the Charcoal canister (that goes to the little tubes under the carb throttle plates) and one in the line from the middle of the Charcoal canister (that goes eventually to the airbox -- not the normal airflow route, but I believe a backfire in the intake tract could "blow" the flow in that direction). With regard to "What is a fair price to pay to have these made?" IMHO something like $150~$200 for a set of 8 would not be unreasonable -- if you'd like a less expensive solution go with the methods suggested by Peter (standard fastener + some machining) or Brian (standard fastener just cutoff). | ||
| '75 308 GT4 (Peter)
Intermediate Member Username: Peter Post Number: 1634 Registered: 12-2000 |
This is what my set-up looks like:  I should clarify, that the Three-way Valve vents the tanks, the carbon canister is just a holding/filtering medium. But as Steve mentioned, the little carbon crumbs could get blown out, hence a filter is an extra safety measure. The orifices to dump the fuel fumes in the intake manifold are microscopic in diameter, it wouldn't take much at all to be blocked by carbon crud. | ||
| '75 308 GT4 (Peter)
Intermediate Member Username: Peter Post Number: 1633 Registered: 12-2000 |
For my carbon canister, I used a Fram G3606 fuel filter, spliced mid-way on the hose to the intake manifold. It is held in a rubber-lined "P-clip" attached at one of the thermostat-neck fasteners. The carbon canister should be retained. It'll vent the gas tanks properly. | ||
| Brian stewart (Eurocardoc)
Junior Member Username: Eurocardoc Post Number: 194 Registered: 11-2001 |
You can buy caphead screws with the correct thread, just cut to length. i use the cut off parts, put a slot across and do a second set of heads. Never had a failure on Fcars or porsche. | ||
| Richelson (Richelson)
Member Username: Richelson Post Number: 500 Registered: 12-2001 |
Steve where do you put the inline filters? What is a fair price to pay to have these made? | ||
| Steve Magnusson (91tr)
Member Username: 91tr Post Number: 560 Registered: 1-2001 |
Steve -- I don't know if you're asking someone a specific question or just in a general way, but I restored/left the fuel vapor control system in place even though I swapped the air injection system in and out a few times (I always liked hearing the airbox flap close at shutoff and the timed small blower fan run as designed on my ex-'78). Other than a little weight it really is a benign system when it comes to affecting performance. I do think it's prudent to add in-line filter(s) where necessary to be additional protection against any loose carbon granules (from the vapor traps) from getting ingested by the intake system. magoo -- the business plan for this stuff never works out which is why you have to do it yourself. I had 2 sets made (which helped keep the unit cost down), and I even sold 1 set for a small profit (the other set I sold for my cost to my ex-service guy for his 308GT4) -- but the Engineering work was/is still basically pro bono. | ||
| Richelson (Richelson)
Member Username: Richelson Post Number: 498 Registered: 12-2001 |
My smog pump was already removed when I purchased my car. It still has the charcoal canister. I didn't remove it. | ||
| Steve (Steve)
Junior Member Username: Steve Post Number: 112 Registered: 2-2001 |
Question here , when you removed the smog equipment did you also remove the carbon filter system? | ||
| Richelson (Richelson)
Member Username: Richelson Post Number: 497 Registered: 12-2001 |
Great info Steve. You did a wonderful job. I am not sure if I should remove everything or put a pump back on. I prefer to have less items around my engine as it makes for easier access but if I had to put it all back on, I don't know. | ||
| magoo (Magoo)
Intermediate Member Username: Magoo Post Number: 2055 Registered: 2-2001 |
Why doesn't someone make these plugs and sell them or is there a place that does sell them rather than having them custom made? | ||
| Steve Magnusson (91tr)
Member Username: 91tr Post Number: 559 Registered: 1-2001 |
Richelson -- An engineer/craftsman who I worked with (some years ago now) had/has a fairly serious machine shop at home and has made many small items I've designed/needed over the years to service/restore/improve the Fs I've owned -- but any Machine Shop should be able to manage it. My original design is optimized for making the plug out of 11/16" hex stainless steel barstock on a lathe where the M14 thread is cut with a single point tool:  Peter's approach using a standard M14 fastener as a starting point is OK too, but I preferred to maintain the smaller 17 mm hex head size identical to the nozzle it replaces:  JPL -- Send me an email address (there's none in your profile), and I'll send the FML article explaining your situation. At a minimum you should replace the check valves with (3/4" NPT I think) pipe caps (if not already done) if you leave the nozzles/manifolds in place with the pump disabled -- JMHO. | ||
| Richelson (Richelson)
Member Username: Richelson Post Number: 493 Registered: 12-2001 |
I have to plug the holes for the air injection. What else do I need to plug? It is a 78'. | ||
| JP Lavigne (Jpl)
New member Username: Jpl Post Number: 26 Registered: 12-2001 |
Where are all of these little plugs, a picture would be great. I picked up my car (78, 308) from Shelton 5 years ago, the pump is there but the belt was disconnected but included in the tool kit. They told me that they could hook it up if I needed it, but as I didn't need I told them not to bother. Should I assume that they put in all of the proper plugs. The car runs fine, at least it does now that I had the points changed to digital. | ||
| magoo (Magoo)
Intermediate Member Username: Magoo Post Number: 2053 Registered: 2-2001 |
THANKS FOR THE CORRECT SIZE PIC PETER. First one I can actually pull up without horiz. scrolling. | ||
| Edward Gault (Irfgt)
Member Username: Irfgt Post Number: 857 Registered: 2-2001 |
What usually happens if you just disconnect the belt from the pump is that water will accumulate in the pipes from condensation and will rust the entire assembly. It is best to use the system or completely remove it. Usually though after all these years you are going to destroy part of it just taking it off due to normal rust. | ||
| Steve Magnusson (91tr)
Member Username: 91tr Post Number: 558 Registered: 1-2001 |
Richelson -- What year/model are you talking about? Generally it's not the greatest idea to just disable the pump itself with no other changes. As I said before, this puts the check valves under full exhaust back pressure constantly and everything else generally suffers too. What do you mean by "CO probes" -- oxygen (lambda) sensor or maybe thermocouples? | ||
| Richelson (Richelson)
Member Username: Richelson Post Number: 492 Registered: 12-2001 |
What happens if the lines are open. On my 308 the smog pump is removed but the lines aren't plugged? My air injectors are still in place and the CO probes are too. I think the line from the diverter valve is open. Does this hurt anything? | ||
| Richelson (Richelson)
Member Username: Richelson Post Number: 491 Registered: 12-2001 |
Steve what do yours look like? Did you make them yourself? (design?) | ||
| Steve Magnusson (91tr)
Member Username: 91tr Post Number: 557 Registered: 1-2001 |
Thanks for the kind words Peter -- but, yes, I still prefer my original 2V air injector plug design with the smaller 17mm external hex head  . I don't know the pump-based 308QV air injection system exactly so I didn't want to get real specific, but if anyone's interested shoot me an email and I'll send a copy of the 308-2V air injector plug design and the related 10 Dec 1994 FML article. | ||
| '75 308 GT4 (Peter)
Intermediate Member Username: Peter Post Number: 1624 Registered: 12-2000 |
With many thanks to Steve M. I now have a properly de-smogged 308. He will point out this isn't his exact design, but does the same job.  Greg, keep all of your smog equipment, working or not. And don't succumb to greed by selling them for a profit on Ebay. In my area, my car got grandfathered in to Collector status without the equipment, but I found out recently I cannot sell my car in Vancouver because without the smog junk, it'll never pass Aircare (and you need this pass in order for the new owner to qualify for his status). | ||
| Paul Newman (Newman)
Junior Member Username: Newman Post Number: 94 Registered: 12-2001 |
Steves right, I would make sure I removed the air nozzles in the heads which abstruct the exhaust flow. Replace them with screw in plugs specifically for this. | ||
| Steve Magnusson (91tr)
Member Username: 91tr Post Number: 556 Registered: 1-2001 |
Greg -- forgot to add that there are probably some one-way check valves somewhere in the air delivery system that shouldn't be relied on to continuously back-seal against the exhaust pressure -- you need to block the exhaust backflow off more securely somehow. | ||
| Steve Magnusson (91tr)
Member Username: 91tr Post Number: 555 Registered: 1-2001 |
Greg -- if you do disable the air injection system, taking the cat(s) off as well will preserve them and you should really look at the rest of the exhaust system for other "obstructions", if any, associated with the air injection system -- wouldn't make sense to leave them in place IMHO if the air delivery system is not functioning. | ||
| Edward Gault (Irfgt)
Member Username: Irfgt Post Number: 854 Registered: 2-2001 |
The smog pump has no effect on the richness of your mixture. It's sole purpose is to supply additional air into the exhaust manifold or catalytic converter to complete the combustion of unburned fuel inside the exhaust manifold or converter. All this is done after the engine combustion process has been completed. The only power robbing effect is the power required to turn thr air pump. Later models have a "pulse air" system that uses the negative exhaust back pressure to draw in the fresh air into the exhaust and does the same thing without the pump. Removing this system will only cause the car to pollute more with no power increase to speak of. | ||
| Greg Rodgers (Joechristmas)
Junior Member Username: Joechristmas Post Number: 127 Registered: 3-2001 |
My QV has a smog pump on it and I don't need it where I am located. If I remove it will there be an issues? I was wondering because I wasn't sure if the mixture might have been set rich because of the smog pump and if I remove it, it may run very rich. You can see what I am getting at. I am just wondering if the car will run just as well if I remove the smog pump or if I need to adjust anything. |