How to time cams for better gas mileage? - Page 3

**ghnl** · #31 (**permalink**) 11-23-2007, 09:38 PM

Great pictures! We like pictures!

Please tell me more about the wrench you are using on the intake cam's nut (55mm wrench). I've been fortunate thus far in that I haven't need to adjust the intake cam. But should I ever need/want to do so I need such a wrench. I tried to make one from a wrench I bought in the plumbing section of Home Depot but that wrench wasn't sturdy enough to loosen the VVT's nut.

TIA,

**ghnl** · #32 (**permalink**) 11-23-2007, 09:41 PM

Thinking about the AFM's spring tension - making it 'softer' meaning less spring tension - wouldn't that allow the 'flapper door' to swing open further & faster? And wouldn't that tell the ECU to send more fuel? I thought your efforts were in search of more MPG's. Or am I not understanding?

NDB · #33 (**permalink**) 11-24-2007, 01:08 AM

Quote:

Originally Posted by ghnl

Great pictures! We like pictures!

Please tell me more about the wrench you are using on the intake cam's nut (55mm wrench). I've been fortunate thus far in that I haven't need to adjust the intake cam. But should I ever need/want to do so I need such a wrench. I tried to make one from a wrench I bought in the plumbing section of Home Depot but that wrench wasn't sturdy enough to loosen the VVT's nut.

TIA,

NDB · #34 (**permalink**) 11-24-2007, 01:11 AM

Quote:

Originally Posted by ghnl

Thinking about the AFM's spring tension - making it 'softer' meaning less spring tension - wouldn't that allow the 'flapper door' to swing open further & faster? And wouldn't that tell the ECU to send more fuel? I thought your efforts were in search of more MPG's. Or am I not understanding?

Joe Papa Sr · #35 (**permalink**) 11-24-2007, 06:41 AM

Quote:

Originally Posted by Tifosi

You can pick up 11 degrees on the intake cam by simply disconnecting the VVT solinoid. (provided yours is electronic and not the mechanical centerfuge version)

Well, 'pick up' is the wrong phrase. More like prevent an 11 degree advance, or, leave the cam 11 degrees retarded. However you want to look at it. :shrug:

That way it'll never kick into power mode and stay in the much 'softer' econo/closed loop (and better emissions) mode most all the time. There will still be a bit of open loop enrichment when you honk down on the throttle, but the intake cam won't kick over to the suck fuel degree index.

I suppose one could even disconnect the full throttle contact at the TPS also so that it didn't even get into an enrichment/open loop mode, but I'd imagine that would turn the car into a downright pig.

Well, actually, no 'imagine' about it, it would turn it into a pig. But hey, if it's mileage you're after, then sacrifices must be made, right?

Still, in a proper state of tune, you should be seeing milage in the upper 20's if not 30mpg range.

If you're not getting around that now, tinkering the cams is going to be far less benificial than an actual factual tune-up.

**ghnl** · #36 (**permalink**) 11-24-2007, 08:01 AM

Quote:

Originally Posted by NDB

yea i know, i gave up on trying to baby the car for gas mileage since i got 27 with slight city driving and then 29 just driving how i wanted. it was strange. so i decided to just have my fun and make some power and see what i get with some of these mods.

**Zunige** · #37 (**permalink**) 11-24-2007, 08:01 AM

Quote:

Originally Posted by Joe Papa Sr

So, back to the VVT...disconnecting it WILL improve mileage without doing harm to the engine? I am really interested in this....how much miles per gallon??
(87 spider)
Thanks!

**ghnl** · #38 (**permalink**) 11-24-2007, 08:03 AM

Quote:

Originally Posted by Joe Papa Sr

So, back to the VVT...disconnecting it WILL improve mileage without doing harm to the engine? I am really interested in this....how much miles per gallon??

**Zunige** · #39 (**permalink**) 11-24-2007, 08:26 AM

Quote:

Originally Posted by ghnl

... Drive a couple of tankfulls with it 'on' then a couple of tankfulls with it 'off' and record your fuel mileage for each. Report back soon!

**ghnl** · #40 (**permalink**) 11-24-2007, 08:31 AM

All in the interest of science, of course...

NDB · #41 (**permalink**) 11-24-2007, 08:59 AM

Sorry, I don't have the electric VVT. It's the hydraulic one. Any way to see if this works or not. Maybe supply some air pressure to the holes and watch it move or something. Also while the cams out, I could count all those splines and find out how many degrees I advanced it. Get some "specs" on it.

**ghnl** · #42 (**permalink**) 11-24-2007, 03:19 PM

Quote:

Originally Posted by NDB

...supply some air pressure to the holes and watch it move or something...

Joe Papa Sr · #43 (**permalink**) 11-24-2007, 03:38 PM

Quote:

Originally Posted by Zunige

Not supplying fuel does mean that you will save fuel, but I can't see how any of this would yield decent power. You're not going to hurt the engine, but it is going to feel like something is wrong. I wouldn't do it. (I also believe Tifosi is providing technical info that is geared more towards understanding the Alfa set-up and how fuel is delivered, rather than as an actual suggestion that this is what anyone should be doing with his/her car.) The '87 should be yielding acceptable gas mileage - mid 20's and much better on the highway. Also, driving the car smoothly does make a big difference in the mpg, even on the highway.

Best regards,

NDB · #44 (**permalink**) 11-24-2007, 04:23 PM

Ok, I'm pretty much done putting the car back together again. Sealed up some exhuast cracks and did some more stuff with the oil system. Here you can see the remote oil filter. This is pretty much the same kit you can order from international auto parts. The filter size for this is massive. I like!!!

Here is the oil thermostat. 180 degrees F

Now I didn't feel the oil cooler was getting sufficient ram air so I decided to make a duct for it. As you can see, this is where I mounted the cooler so it wouldn't interfere with the radiator cooling efficiency. The oil cooler is very large. There is still another coil hidden behind the bumper in the picture. The oil capacity when I first put the engine back together with the cooler system and all was just over 8 quarts. With an oil change, it uses 7 quarts.

And as you could see the air filter is attach to some SCAT tubing. This cold air should really help the AFM with the extra fuel.

Now, for the oil cooler situation. I had to think of some way to duck the ram air towards the coils, so came up with an idea. I got a pretty hefty paint tray. Obviously there were many types so I had to get one large enough and durable enough for this application.

Cut it to form and fit the way I needed it.

I painted it with some coats of truck bed liner to give it some rigidity the installed it with some zip-ties. You can see where it mates up with the cooler.

I think it will do very well in supplying airflow.