Keep Dellorto DRLA 45s and Bosch 009? Options

[98101]

I suddenly find myself owning 1970 4-cylinder 2.4 with Web hot street Cam idles nicely and pulls hard at WOT. Part throttle response is not great, often with carbs coughing and even backfiring on trailing throttle. My use is mostly street, so I'd like to get this part throttle stuff sorted.

Here's pictures of the stuff that's in there now. I guess that's the infamous Bosch 009 with no vacuum advance and a PerTronix 1847A. The carbs are Dellorto DRLA 45s with short velocity stacks and these tall foam things that don't seal against the air cleaner housings. I'm willing to learn about the carbs but I don't have much confidence in the 009 for running nicely on the street. Please correct me if I'm wrong about any of this stuff.

Also from other threads I gather that switching to EFI such as MicroSquirt would cost $5K or so ... though I'm not ruling this out completely. Correct me if I'm wrong about that.






Is this kind of linkage OK?


Here's the idle you may have seen in another post:

https://www.youtube.com/watch?v=-AC53RRrXOU


Any help you can provide is appreciated!

--Michael in Seattle

[porschetub]

In your carb pic the vacuum advance port isn't capped off ??
If you are infact running a 09 it will need to capped off,check the other side carb also ,you may or may not have the same there.
Do you know the spec's of the carbs ?? ,been said many times but they are still large carbs for even a 2.4 if not setup right...that will leave a very soggy mid range if not right.
If your carbs are close to being dialed in you could try a vacuum advance dizzy such as the SVDA or 034 (?) Bosch type if you have vacuum ports on both carbs ,larger carbs and a hot street cam will most like see the 09 being even less desirable.
Are you running the right fuel pressure ?,is your fuel from a regulated source or direct from a LP pump ?.
Someone like John Walker will most likely need to see the engine fully tuned (plugs ,leads,timing and valve clearances ) before he will attempt tuning the carbs ,that's the order its done in.

[98101]

In your carb pic the vacuum advance port isn't capped off ??

Whoa, in the photo it sure looks like it’s not sealed! I’ll check both of those. Now I’m confused how it could idle so smoothly. I guess I should check for vacuum leaks in general.

Thank you (and everyone else) for this help. With my first two 914s in the 1980s I was pretty much alone with these problems, unless you count the Haynes manual. Now the cars are much older but there’s so much more advice online. Also I don’t have to live in fear of getting it back together by morning since I don’t depend on it to get to work. And spending money on stuff is way less of a problem now.

OTOH, wife does not understand why I’d spend time on this at all! She was especially annoyed when I told her I’d keep my Miata as a rain car. Why would this annoy her any more than me upgrading the SSD in my computer?

Anyway, thanks all. You’ve given me a lot of homework and I’ll do my best.