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Imps and valve adjustments

BoyToys

Active member
Had what looked Iike a slight oil leak from the valve covers, so ordered new gaskets. While I'm in there....took the time to paint the valve covers in something other than rust AND might just as well adjust the valves. Uggh, a bit of a PITA since access to the front of the engine in order to turn the crank is difficult to say the least. Dog house comes off, alternator comes off, ratchet and 11/16" socket snaked in between the fan blade and the crank pulley in order to rotate the engine.
So, searched the web and came up with some Saab V4 instructions for the valves. Been a long long long (did I mention long) time since I last adjusted valves on a vehicle but no problem. All but one were too loose (no surprise) and one exhaust valve had almost zero clearance (no bueno). .014" intake, .016" exhaust.
All good now, purrs like a kitten. Tomorrow I'll check the ignition timing @6°btdc while I still have a very narrow window of access laying on my stomach on the passenger floor and squinting beneath the alternator for a glimpse of the timing marks.
Here's a link to the Saab manual I was using.

 

zspryte

Member
Site Supporter
If you are operating at a non-trivial altitude you may need to advance the timing beyond what the factory says it should be at sea level.
 

BoyToys

Active member
If you are operating at a non-trivial altitude you may need to advance the timing beyond what the factory says it should be at sea level.
Interesting, I would never have thought of that. I'll be operating at about 3500 feet so most likely factory specs would be fine. There's probably a chart somewhere on the web comparing timing to altitude.
 

BoyToys

Active member
FYI, information specific to V4's used in Saabs. 1/2° advance for every 1000 feet above 2000 feet elevation. So in my case I would want to add .75 - 1.0 degree for running at 3500 - 3800 elevation.
 

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BoyToys

Active member
FYI, information specific to V4's used in Saabs. 1/2° advance for every 1000 feet above 2000 feet elevation. So in my case I would want to add .75 - 1.0 degree for running at 3500 - 3800 elevation.
One more piece of info: checked ignition timing today (vacuum advance line disconnected) and....holy crap batman, the previous owner or his main-man wrench had the timing set at least 20° advanced. Must have been running this Imp at 20,000' elevation. Easy 10 second fix, now set at about 7° btdc for my intended altitude.
But hey, you buy a bargain basement machine with dubious history, just waiting for the next discovery.
 

redsqwrl

Bronze Member
GOLD Site Supporter
Peanut gallery input. Next time.... put front trans in 3rd. Rear in neutral.

Use drive shaft to turn engine.....
Why.

That crank pulley.... is. The. Cam. Shaft. And it has a plastic or phenolic gear on it. You wont be the first guy to crack one in summer then be crabby about it in winter....
 

BoyToys

Active member
Peanut gallery input. Next time.... put front trans in 3rd. Rear in neutral.

Use drive shaft to turn engine.....
Why.

That crank pulley.... is. The. Cam. Shaft. And it has a plastic or phenolic gear on it. You wont be the first guy to crack one in summer then be crabby about it in winter....
Ahhh...didn't know that. Initially I was going to do as you suggested but was able to access the pulley so just did it the "traditional" way.
These old V4's are strange machines
 

redsqwrl

Bronze Member
GOLD Site Supporter
Strange is an understatement, I apprenticed at a saab shop here north of road america in elkheart lake WI. ( apprentice = stood around asking dumb questions) These engines make a LOT of power and spin to the moon. ( the internet knows better and they are all junk ) ford built them for the euro market. lots of them made it here as industrial power plants. they are wicked in the right hands. every few years I bring an imp to the clowder and weave in and out of the orange slow kids. Lock the gate, let the group get far enough away to get lost, run them down pass them or pick up their parts or both...... :cool:))))) just kidding. enjoy the learning curve. dont be afraid to build a 2.0L version and swap it out when know one is looking.
 

BoyToys

Active member
Gets my adrenaline pumping! Did I hear you upshifting at the 15 second point of the video? I guess if you're moving along fast enough in relatively shallow snow you won't lose too much forward motion. Share what rear and front gears your were in.
This coming winter my Imp will be snow worthy and I can hardly wait to learn how to operate it, but meanwhile I'm becoming very mechanically intimate with her.
 

BoyToys

Active member
I don't know how fast you're going there, but I am dreaming of matching a similar speed and breaking the 4 MPH speed I seem to be topping out on.
I think these are rated at 25mph max but personally that would scare me to death unless on open ground. My new to me Imp at some point made serious contact with a tree with some barely passable sheet metal repair work as a result. A little grinding, sealing, Bondo, and paint will take care of it during this summer's restoration work. She won't be a garage queen but ask me if I care.
 

ViaLisboa

New member
I think these are rated at 25mph max but personally that would scare me to death unless on open ground.
My problem / concern is that I am maxing out at 4 MPH. In the 2nd lowest gearing and I cannot jump any higher without stalling out or losing speed. So I sit red-lining at 3k rpm going 4MPH.

So at a minimum, a valve adjustment and timing adjustment I think is in order.
 

redsqwrl

Bronze Member
GOLD Site Supporter
Gets my adrenaline pumping! Did I hear you upshifting at the 15 second point of the video? I guess if you're moving along fast enough in relatively shallow snow you won't lose too much forward motion. Share what rear and front gears your were in.
This coming winter my Imp will be snow worthy and I can hardly wait to learn how to operate it, but meanwhile I'm becoming very mechanically intimate with her.
That was was likely 3rd range and second to 3rd gear shifts. The snow was mostly floof. My role at the event is herding. Herding involves gates (opening and closing) and broken machines. I often need to catch up, or run for stuff.

3k is not even close to redline. Im usually 2400 to 2600 rpm.
 

BoyToys

Active member
My problem / concern is that I am maxing out at 4 MPH. In the 2nd lowest gearing and I cannot jump any higher without stalling out or losing speed. So I sit red-lining at 3k rpm going 4MPH.

So at a minimum, a valve adjustment and timing adjustment I think is in order.
Unfortunately I don't have any trail experience yet since all I've done is plow my driveway once I got it operational this winter, using 2nd gear in the C4 rear just 1st in the tranny. I imagine shifting up on the fly would be like in your truck keeping your foot on the break while stuffing in the clutch to shift. With all the belt/grouser drag and lower gearing on these cats, you would lose speed quickly and end up either stopping completely or lugging out and stalling. Now if your engine is stalling out when you stuff in the clutch, that speaks to carburetor adjustment being perhaps too lean. Check timing, bump it up 1° btdc for each additional 1000 feet above 2000 base, dial in the carb mixture to lean best idle and maybe a 1/4 turn or so richer on the jet, and adjust the valves if in doubt (cold, .014 intake and .016 exhaust).
 
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