Geo Metro XFi cam swap How To

[Johnny Mullet]

This has been long overdue, but the time has arrived for me to finally swap in my 3Tech economy cam and advanced timing gear. I was going to wait until my other head project was done and just swap heads, but I can always transfer the parts. The car (Christine) is in the bay waiting patiently..............



First thing is to remove the air cleaner assy and unhook the PCV hose and plug wires from the valve cover. To remove the valve cover, you need to remove the 4 nuts and then strike the seals counter-clockwise with a small hammer and screwdriver until you can get some pliers on them to thread them off without damage.........





Remove the valve cover. Now we go to the water pump pulley and remove the 4 bolts with the belt still attached. You might have to use a screwdriver to hold it still.............



Pop off the pulley and drive belt and this will expose the timing belt cover for removal, but first we need to remove the crank pulley. Jack up and safely set on stands and remove the right front tire. Now remove the small mounting bolts (older models have 4 and newer models have 5) and the pulley should come off with a couple whacks with a soft hammer.............



Now you can remove all the timing cover bolts and remove the cover.............



Line up the timing marks on the crankshaft pulley by rotating the engine slowly. Removing the plugs to relieve compression helps, but not needed.............



Mark the timing belt with an arrow noting the rotation direction if you are re-using it..............



Loosen the timing belt tensioner and remove the belt. Replace the belt if it looks due or questionable............



Now we get to remove the camshaft. You can use a screwdriver through the cam holes if you rotate it and slide it through to hold it still so you can loosen the cam gear bolt or use an impact when it's out. Here is a reference pic so you understand..........
CLICK

Now remove the sideways bolt in cam cap #3...........



Slowly loosen the 6 cam cap bolts. You may turn the cam slightly to relieve pressure from the lifters. This will not hurt anything, but please note the position of the distributor tabs and don't let it rotate after the cam is out. Remove the cam noting and comparing with the new cam so you know how it goes back together. Get a green scotch brite pad and clean all the cam journals and cam caps so they are nice and smooth again, but be careful not to turn the distributor tabs.............





Get your new parts ready. I got the economy cam and gear and a new cam seal (Federal Mogul # 710310). Please note that older models have a solid cam gear, but the guide is the same. ...........



Install the cam seal with a finger swipe of oil around the inner part and then use some locktite and install the cam gear to the cam and torque the bolt to 44 Ft lbs (all years) making note of the new marks on the cam gear if you have an advanced gear from 3Tech........



Now liberally coat the cam lobes and journals with motor oil................



Install the cam like you removed the old one and line it up to the distributor tabs...........



Make sure the cam seal is lined properly and install the cam caps and torque to 96 in-lbs (all years)...........



If you slightly rotated the cam during removal to relieve pressure, now is the time to rotate the cam back. Set the valve cover on so you can line the new mark with the notch in the cover.......

Install the timing belt and rotate the engine by hand 2 revolutions until the marks line up again and make sure they are correct..........



Tighten the tensioner and re-assemble the rest just like you took it apart. Take an initial test drive and listen for engine ping (spark knock) while driving. If it is, then most likely, you are off by one tooth. Remove the belt and turn the cam counterclockwise one notch. If you notice lack of low end power, but good power at high RPM's, then turn the cam clockwise one tooth. You should be able to run this with the distributor fully advanced with the gear.

Hope this helps someone out there interested in these parts but worried about installation. Here are more torque specs if you need them.........
Torque Specs

[99metro]

MPG numbers? Like you said, it'll take awhile to run the tank down.

[grumalt]

The guy that rebuild my head put the timming pully on in the wrong spot.

i was looking at that 2nd to last photo =



in that photo is that the way the cam should be turned for Top Dead Center?
If so great i can put it together that way.

[Johnny Mullet]

[grumalt]

Question: can the OEM CamShaft Sproket be put on wrong? if so how do i find the new TDC without using the Timing Marks?

[MetroMPG]

Driving impressions? I wonder if you were as impressed with the change in the engine's character as I was.

[Johnny Mullet]

Well, I was impressed after I got it going. You can really feel the power in 4TH and 5TH gear and no need to downshift anymore. The true test was to let my wife drive the car, so yesterday I let her take it to the store. When she came back, she was like..........

"What did you do to the Metro? It's got power now!"

I still have like 1/2 a tank of fuel since the swap and fillup and gone almost 300 miles. I know there will be at least a 3MPG increase from the cam, but it will actually take a few tankfulls to get real numbers.

[MetroMPG]

She didn't know you'd done the mod? Excellent!

Thanks for posting the writeup.

[dcb]

Johnny, were there any changes to the ignition timing?

Originally Posted by grumalt

if so how do i find the new TDC without using the Timing Marks?

carefully. I use a screwdriver inserted into the sparkplug hole a fixed depth and rotate the engine till the piston touches it in one direction, and note the angle, then in the other direction (again note the angle) and split the difference.

[Johnny Mullet]

If you leave the stock timing settings and the cam gear is correct, you should hear no pinging or valve clatter. If you do, you are advanced a tooth and need to reset the cam timing.

I was able to advance my ignition timing (distributor) quite a bit after the swap. I cranked it to full advance, test drove it, and had to back it off slightly for ping. I do not use a timing light on these cars. It's a matter of finding the sweet spot by ear.


MetroMPG, My wife has no idea I dropped those parts in. She remembers the package that was delivered from 3Tech, but that was 6 weeks ago.