Timing vacuum advance needed

[jebudallaha]

If anyone out there has a functional one kicking around let me know, I'm in the market; not having any power is getting to be a drag. If you're not willing to dissect a distributor, I might be talked into buying the whole setup (though ideally, I only need the vacuum advance). Drop me a note with your price, thanks!

[dlb]

user 4wdchico posted this info on new vac cannisters a while back:

"If you end up needing a new vac advance unit Standard Motor Products p/n VC360 is the OE Nippon Denso unit. Last time I priced the VC360, Amazon had the best price."

and just so you know and aren't sorely disappointed when you get one hooked up, it doesn't increase power or performance. manifold vacuum, which is the port that the upper vac can is attached to, advances the timing during highway cruising and idling. ported vacuum, which is the port that the lower vac can is attached to, only advances the timing during highway cruising. the point of vac advance is that during idle and highway cruising, engines run more lean, and lean mixtures take longer to burn. so by advancing the timing during idle and cruising you are allowing the engine enough time to properly burn the fuel which would otherwise be spat out half-burnt passed the exhaust valve, increasing emissions and exhaust temperature. so this is still definitely something you should do, as your engine will run cooler and you'll likely see an improvement in fuel economy, but just be aware that it won't affect other things.

[Petros]

As DLB stated, you will not get more power with a new vac adavace. In fact you can not even tell the differenace when you drive it if the vac adance works at all or not. To get more power you need to first make sure everything is running properly: carb, mechanical advance is working, no vac leaks, etc. Than set timing at 10 or 12 deg BTDC rather than factory 5 deg. Replace the factory cam with a performance regrind from Delta Cams in Tacoma WA (about $60 exchange, plus shipping). Try a 2" exhaust sytem with "tubo" muffler, and finally if that is not enough than spend the big bucks and add a weber carb, and do a complete performance overhaul. You should be up to about 80+ hp.

And if that is not quite enough for you the only thing left is to do an engine swap, 4age is the best, but 4afe is a high torque engine (and more common), or you can go 4ac, which is an easy swap but does not get you as much hp.

[jebudallaha]

Thanks DLB and Petros, I know that a new vacuum advance (and know the theory and functionality of one) isn't going to make any appreciable difference as far as power is concerned in and of itself; it's just the first piece in getting everything dialed in. The diaphragm in the upper section of the advance is torn which is causing a vacuum leak(which is where I'll get some of my power back by replacing the vacuum advance, not by the actual timing advancement). I could just plug the line, but as DLB said having the advance helps with economy and engine longevity and it's a simple replacement so might as well. I may have exaggerated my power woes a bit (in comparison to some of the other stock tercs I've been around mine is above average) there are just a couple little hiccups here and there that need to be addressed.

Thanks for looking out for my pride guys!