308 injection valve delete

Hello,

would anyone know a source where I could buy injection valve delete bolts? I am removing the smog system from my 1978 308

thanks

 

If by "injection valve delete bolts" you mean the special plugs to replace the air injection nozzles in the cylinder head, try contacting Verell at Unobtainium Supply: http://www.unobtainiumsupply.com

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Yes sir!! Thank you so much

 

I have a few red sets left. Longer than Verrel's so you can cut them flush with the port to avoid whistling (put them in, run a few hours, mark orientation, remove them, cut off the discoloured end and replace to same position.) If you want silver use dilute draino to remove the red anodising. £60 plus post (probably £8 to the US.)
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Hello,

Just so I understand. Are you saying the ones offered by Unobtainium Supply will whistle or that the ones you have will until they are cut flush?

 

I have the Unobtainium plugs on my 1982 308GTSi.... no whistle.....

 

Using plugs with no "nose projection" feature at all are the ones that can whistle on 308/328 -- there is a standard DIN hydraulic port plug, without a nose projection, that works OK on Porsche engines of the same era, but has the whistling issue if used on 308/328 engines due to the difference in the cylinder head design of how the threaded hole for the plug intersects the exhaust port path.

 

Sounds like Verells don’t whistle. Thanks for the correction Steve.

 

Neither of those shown will whistle, the longer stub simply mimics the stock length of the original perforated tube, which also jutted that far into the exhaust port air flow...

 

That's a clever approach, good idea to manufacture long and cut to the appropriate length based on observed flow.
I bought my set from smg2 (Scott) here on ferrarichat, they also have the standard/ready to go, protruding nose projection.

 

Dumb question (sorry): Why remove the smog system? Just to simplify maintenance or, is there a noticable performance improvement? Also, is there any concern about loss of originality?

 

People just like to junk things, it's actually a Federal Crime.

That said, our air pumps were cam driven and I always feared a seizure would stop the cam, (probably needlessly never heard of it happening).

But Real World:
The perforated injection nozzles over time would melt, bend, clog, and so forth.
The metal steel tubing between to pumps and the head would rot out and make an exhaust leak in back flow.
The whole system was a complex attempt to fool the Smog Sampling at the exhaust, in regards to unburned HC and CO levels, which in all of Amerika except Cali, is now under the "25 years old we don't care" Exemption.

But simply as a data point, with ALL of it in the trash and running a four tip ANSA, with careful tuning of the carbs before testing (colortune glass spark plugs to verify air mixture)...my car would PASS in Texas before it went exempt..

 

Performance in these cars is in the air/fuel ratio and ignition performance....after that "it is what it is"......

 

I removed mine because one of the "sampling tubes" corroded, thus creating an exhaust leak. Repairing the tube would have been a pain, and the small engine bay already has so much "extra" stuff in it, so I replace the system with plugs. I have now forgotten exactly how I did it, but I just used some off the shelf stainless screws that matched the threads and cut them to the correct length. No whistling or leaks. That was probably 10 years ago.

 

An oldie but a goodie. Make your own plugs, for free!

See post no. 16, here: The Dreaded 308 Exhaust Whistle | FerrariChat

 

With all due respect, Secondary Air Injection (SAI) was, and is, a standard and real approach to control vehicle emissions. At least in the case of US based 308 Carb and injected cars, this led to Ferrari insulating the headers to "keep the heat in" for ASAP firing of the catalytic converters, in conjunction with the SAI. A quote from the Wiki page link: "When the catalytic converter is cold, air injected at the upstream point burns with the deliberately rich exhaust so as to bring the catalyst up to operating temperature quickly." I have fought many BMW SAI woes...

 

Tex,

When I got my car, the air pump was FROZEN SOLID.

Just Sayin'

 

Well IF the belt did not slip and burn (the weak link actually)......there you go!

It's a GM part as they went catalyst in 1976.
Ferrari got two more years.
Well, one and a half maybe as they made all the "1977"s they could.

 

I got that.

The modern method would be an electric air pump at 12V and get it all going, but for my 1976 -1977s I have NO CATS to fire off...

 

Air pumps have a pressure spec. Check WSM. I've seen plenty not blowing enough to get past check valves. If they're working, CO and HC drop like a stone.

 

No belt was on it when I got it, so no idea.

Pulled-Off or Burned-Off? No idea.


As far as I was concerned, it was a self-deleating system so the rest of it came off.

Why exactly does a cat HAVE TO heat-up SO FAST (seconds vs a couple of minutes) to the (severe?) detriment of the overall health/longevity of the engine?

Only politicians of the day could 'logic' that.

 

Mmmm, as far as I know, late 308 QV's like mine, and all 328's have short secondary air-injection fittings. And most don't whistle. The long perforated nozzle is only on the cars with a smog pump. When they switched to a pulse-air system (some time in '84, I think), they deleted that projection entirely.

I just pulled out all 8 of mine, and they all end at the threaded portion. Per the parts manual diagrams, this is the way they should look. (IE: no one took them out, chopped the ends off and put them back in.

At first, this discussion prompted me to wonder if I had erred by ordering (and installing) a set of the standard DIN plugs mentioned earlier (that is, flat-bottomed). My motor is still sitting on a stand vice in the car, so can't exactly fire it up and see if it whistles, but . . . It never DID whistle before, and given the fact that I now have solid plugs of the same length of the original hollow plugs, and none of that extra open tubing beyond, I can't see how I would have created or increased any resonance.

Then again, maybe it's been whistling all along, but I didn't know it because I've lost most of my higher frequency hearing to helicopter turbines and tail-rotors... In which case, I suppose, whistle away!

 

Yes, you are right -- I should've limited that comment to US 308-2V models (and maybe 1983 US 308QV. I'm not sure about that one as the nozzle and exhaust port designs are different from the 2-Valves. The hole for the nozzle is sort of shielded from the exhaust flows by a web of material and between the two exhaust flows; whereas, on the 2-Valves, it's located in the worst possible place for maximum impingement of the single exhaust flow. I believe on the later US 308QV and US 328 the hole is still in the same place as the 1983 US 308QV). When I did the original design for the 2-valve plug, my reason for adding the nose projection was to keep the hole in the cyl head clear of carbon build-up as I was swapping in the stock system every one or two years for California and Colorado emission testing. Didn't know that it was necessary to prevent whistling until later reports of people having whistling without the nose projection. I didn't do a 308QV/328 plug design so don't know if the nose projection was included specifically for 1983 US 308QV, or if it was just copied over.

 

I don't know if the early QV's with smog pumps had those little perforated extensions or not. Just speculating. I suspect they did, based on the way a positive-pressure smog pump works vice a pulse-air system on the later cars. The screen projection was probably there to stop the exhaust flow from working against the pump pressure; while a passive system just uses the flow itself, blowing over an open aperture to suck fresh air in through a one-way valve. Sound logical?

 

On the 1983 US 308QV, they shortened up the "nozzle" so that it doesn't intrude into the exhaust stream hardly at all (so no perforations):

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It seems like they then realized that the solid tube portion really wasn't needed so went to the simple male-male threaded union in 1984.