Any reason to remove the plenum?

Someone please chime in here. I don't believe they are supposed to be braised or welded. In fact Ettore Palazzo had a set of the threaded retainers for sale not long ago, they were brand new and quite reasonably priced. There is a separate thread somewhere about replacing the Fuel Injectors. I had a heck of a job getting to the nuts to remove the Plenum. Only reason was, it needed to be re-finished al<script id="gpt-impl-0.041650034592867646" src="https://securepubads.g.doubleclick.net/gpt/pubads_impl_108.js"></script>ong with the Throttle Body. I decided to replace the Injectors with the later Brass Type. Apparently they have a slightly higher pressure spring and atomize the fuel better, also the spray pattern is a bit better. Seat of the pants evaluation for me is that it is better. Car runs better, starts easier, etc. In the other thread, people have had similar experiences. Check it out.
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Sorry, I don't know what happened in the middle of my script, but I guess you get the idea.

 

Under the Plenum -

This fitting #26 corrodes for some reason. It will eventually cause a coolant leak. Hill Engineering makes a stainless steel replacement.

Ferrari 308 GTSi (1981) Mechanical Table 017 Water Pump, Lines

106241 UNION - Ricambi America, Inc.

 

Karl gave me a heads up about this thread (thanks Karl). I suspect that the braising of injectors to the carriers was not a factory/dealer protocol. I have been messing around with the CIS systems on these cars for a few years now and having cleaned and tested nearly 200 old style injectors (Bosch 0437502010) I have never seen any evidence of this sort of modification on the injectors that have passed through my hands. It would be interesting to know if the likes of Dave Helms or Brian Crall have ever seen something like this. As Karl mentioned, I do have a set of injector carriers for sale, however, they are pending sale.

While we're on the subject of injectors, it is true that the brass version (Bosch 0437502047) is indeed the Bosch approved replacement for the steel injectors as the -010 versions went out of production in 2011. Having tested both types I can confirm that the brass version does have an average higher opening pressure by approximately 0.5 bar (approx. 3.5 bar for -010 vs. approx. 4.0 bar for -047). This difference shouldn't affect drivability as the primary pressure in the Bosch CIS system is significantly higher than the opening pressure of either type of injector. That stated, it is my opinion that the difference in spray pattern does have the potential to affect drivability. In particular, the original steel injectors have a 35 degree spray pattern while the brass injector spray pattern is wider (about 42 degrees). You can do a search on steel injectors to review prior discussions on the subject but some have postulated that the wider spray pattern may result in more fuel hitting the walls of the intake manifold resulting in a less than favorable AFR. You may ask how this can be true when folks frequently report improvements when switching from steel to brass as Karl described above. No question that a new brass injector will perform better than a 30+ year old steel injector that has never been serviced. The real question is how do brass injectors compare to a set of steel injectors after they have been cleaned, and better yet, balanced? I have gone through this on my 328 and no question I would choose a set of steel injectors that have been serviced over brass every time.

So what's the point of this long rant? Don't throw your old steel injectors out, consider getting an injector shop to clean and test them. If they have stable opening pressures and are leak free I would put them back in the car rather than switching to brass. At the very least, keep them on the shelf to use as back ups.

 

Haha! Made my day!

 

Or you can get a brass one at any auto parts store.

 

Michael, as long as you're in there, wouldn't hurt to remove the Plenum just to change out the two small coolant hoses that run underneath it. Not a big job at all, but remember to slide a piece of paper between the Plenum and ports before you go and pull it off as there is a chance of dropping one of the round spacers down the port. Looking good!