I recently had my 914 emissions tested and it failed. Yes, in Delaware all cars newer than 1969 have to pass emissions. Anyway, this failure brought to my attention that the combination of engine specs and fuel injection are causing this problem. I had an enlightening conversation with Jake Raby about what I had and he basically said that the reason for the emissions problem is that the cam I have is too radical for D-jet. He said he was surprised it ran at all. It does, but has no guts after 4k RPM.

So here is what I have:

The engine was rebuilt 20 years ago after some sort of catastrophic failure. It was originally a 2.0, and is now a 2056. The cam is listed on the paperwork as 272 degree. Jake said this is pretty radical for a 2056. The original owner told me he used to have dual carbs on the car, but decided to put the D-jet back on because of emissions. Ha!

I was already planning to do some upgrades to the valve train because it is seriously noisy. The rocker arm springs must be getting shoved around too much by that cam. Solid rocker spacers and possibly 911 adjusters/1.7 rockers were on my to-do list anyway. So what I need to decide is which way to go with reconfiguring this combo. I could pull off the D-jet and throw some gnarly Webers on, or possibly an updated injection system. Or, I could crack open the case and replace the cam with something milder that will work with D-jet.

This is just a daily driver type car. I want something that works, is fairly reliable, and won't require too much tinkering. At least, not any more than one would expect for a 35 year-old car. I also want to keep the budget for this operation at a minimum.

What to do...?

An engine geometry thread... Sweeeeeet!

replace the camshaft.
If you have a carbed camshaft it creates to much fluxation in the manifold pressure. The MPS sees this as a lean condition and enriches the mixture to compensate.

That being said, it could be tuned out with a wide band O2 sensor/meter, but I think its easier to replace the camshaft.

Buy the camshaft and lifters from jake and stop worrying about the valve springs..though his new keepers are nice, and the 911 swivel foot adjusters do save your valve stems.

Rich

Rich,

Thanks for your advice. You echoed what was echoing in my head. Replacing the camshaft sounds like the most sensible thing to do. I would really like to nip this issue in the bud and get on with driving the car. I was hoping to avoid opening the case, because I've never done it before, but screwing around with carbs doesn't appeal to me either. And the springs I was talking about are the ones between the rocker arms, not the valve springs. I'm going to put the solid spacers in there to eliminate them. Now, to call Jake for a tasty new cam and then

Eric, I'm always happy to provide entertainment for my friends.

Opening up the case is not to bad if you approach it the right way.
Get a large table to work on, get a cleaning pan to clean everything.

Pressure wash the motor just before you open it...get as much crap off as possible, but then open it up and dry off anything you got wet.

Its just a big jigsaw puzzle. There are plenty of books and help to get it done.
Measure everything...
Bring the case and crank to a machine shop and have it measured.
Get new bearings and have the rods rebushed...

Rich

Do I need to buy an engine stand for the rebuild, or can all the work be done on a table? Holy s--t, now I need to start reading all the rebuild threads. Somebody throw me a line!!! I'm slipping down this crazy slope!! The ground was level just a minute ago. Ahhhhhhh.......

You're in waaaay deeper that I have ever been, but from previous threads:
1. Buy jake's video. Watch it many, many times.
2. Listen to Jake and use his advice.
3. Jake's forum will be opened to you upon purchase, and I am told that the advice there is invaluable.

And since you are happy to provide entertainment to you friends, please post your progress in a thread here. I am planning to upgrade my engine with one of Jake's kit in the next year, and in the mean time, I am soaking up every bit of knowledge I can get my hands on.

Thanks, and good luck!!!

I've assisted in assembling a couple of air cooled 4's and Jakes video would probably make this job waaay easier then not. It's not a walk in the park for the uninitiated. (I hate those push rod tube seals...)

It is impossible to "tune out" the vacuum pulses and high HC and CO on a 270 degree cam no matter what fuel system you are using. Too much overlap of valve timing.

My $0.02. =)

Our forums are open to anyone, you don't have to be a purchaser.. We do have some private forums that can only be seen by the purchasers of complete engines and kits, but most all info there is open..

Yes, you have a misconfiguration- no doubt. the best way to remedy it is to redesign the engine, not the cheapest, but the most effective means of having real fun with your car..

I'm not familiar with Delaware but my guess is that if they are checking emmisions out of the pipe they are also doing a visual equipment check. Switching to carbs would cause you to fail the visual regardless of how clean the exhaust is.

I'll be calling you soon, Jake. Thanks again for your advice last week. Looks like I have a summer project now.

They didn't look under the engine lid when I went through the first time. Not sure if they would have, had I passed the test. Anyway, I was just starting to get to know the stock injection. And if what Dr. Roger said is true, I would have wasted a lot of money on carbs that would have done no good at all.

I had dreamed about doing a rebuild at some point in the future, but had no idea it would need to happen so soon. I have to get my girlfriend's garage straightened up so I can use it as my engine shop! There might even be a work bench somewhere under all that stuff.

Think of this as an "Opportunity".. Thats what it is!

You'll have fun. Do it right.

Jake, I just ordered your type IV rebuild video. Time to start my parts list. After I watch the video I'll start ordering what I need. In the mean time, I'll be looking for a decent machine shop in my area to check out the case and crank, as Rich suggested.

I've already read a couple of rebuild threads here, and I see that I have some high standards to measure up to if I want to post pictures of what I do.

you can get a 750 # engine stand from harbor freight tools for $40. then the adapter plate from mainely custom by design for $150 (well, you saved money on the stand....). i'm surprised DE makes a 30 yr old car meet current standards.

its nice to have a stand...I have three.
I also have used a milk crate many times...on top of the table.
You can lay the case in the open milk crate and the head studs wont hit the table...
You really only need/want the motor on its side to assemble the lower end. The rest can be done on the table with the motor sitting horizontal.

You may want to think long and hard about buying a "kit" from Jake.
a big reason to do that is Jake will help you...its part of his service.
His kit has all the parts you need.
Seeing as you are in DE...take it apart and (if you buy a kit from Jake) ship him the case and let him inspect it...who better, right?
Rich

What about a bench-mount stand that I've seen in a recent rebuild thread? Anybody know where I can get one of those?

Believe it or not, DE has fairly stringent air quality standards. I don't know the specifics, but I think we are considered to be in the same region as Philadelphia in that respect.

Rich, I have thought many times about buying a kit from Jake. I also thought it was something I would have time to save for. I have done no such saving. This rebuild 'opportunity' has taken me by surprise. However, I have time to plan what to do. I'm not going to run out and start buying stuff without a plan. Maybe I can sell half (or all) of my worldly posessions and come up with the scratch. I'll keep an open mind, anyway. When the time comes to make a purchase, I may be in a better position than I am predicting right now. Cross your finger for me.