1974 XJ12 Chevy 350 conv.
 

Hello all, Michael here. I'm a jeep guy but crossed over to the jag world this weekend. i just bought a 74 XJ12 that has a Chevy 350 in it for $400. The car runs i just need to drop the gas tanks and clean them out since it's been sitting for a while. I think i got a pretty good deal. The body is in great shape even though it desperately needs a paint job. I've got the Haynes manuals for it too. I mainly just wanted to introduce myself and ask a few questions. When trying to remove the fuel filler cap flange, there are 4 flat head screws that hold it on, which i removed, along with the side bumper and quarter panel and "luggage boot" casing (as the Brits call it) (or trunk panelsas i callthem)and several other bolts but the tank does not even move. My questions are, how does the fuel filler cap flange come out? The manual says it pops out but the flange says no way. Here are some pics for your enjoyment: (maybe they will show up)

http://i178.photobucket.com/albums/w...y/DSCF1683.jpg

http://i178.photobucket.com/albums/w...y/DSCF1684.jpg

http://i178.photobucket.com/albums/w...y/DSCF1685.jpg

http://i178.photobucket.com/albums/w...y/DSCF1686.jpg

http://i178.photobucket.com/albums/w...Jaguar2004.jpg

and here's my jeep:
http://i178.photobucket.com/albums/w...DSCF1503-1.jpg

RE: 1974 XJ12 Chevy 350 conv.
 

they didn't show so i just put the link to them

RE: 1974 XJ12 Chevy 350 conv.
 

oh yeah, one more question, what type of tranny would this thing have? I almost think the original tranny would have bolted to the 350. Could it be a turbo 400? Or is it most likelyone that came out of the same truck that the motor came out of? It's an auto btw.

RE: 1974 XJ12 Chevy 350 conv.
 

I'll check into the tanks. Not too familiar with the Series 2 cars. The OE transmission would not bolt up to the 350 engine.

RE: 1974 XJ12 Chevy 350 conv.
 

awesome, that'd be great. the flange just baffled me for some reason.The haynes manual says to just remove the 4 screws and pop the flange off with a screw driver, being careful not to damage the body/paint. But it would not even budge and i definitely don't wanna break it. Any more tips to removing a fuel tank would be cool too. Thanks again!

I guess i'll have to get some numbers off the tranny. I hope it's a t700r.

RE: 1974 XJ12 Chevy 350 conv.
 

one more thing, this car would have 5 on 4.75" bolt pattern right? Or is it 5 on 4.5"?

RE: 1974 XJ12 Chevy 350 conv.
 

Alright, just an update here. I finally got the gas tank out. The biggest problem i had was getting the flange off (where you stick the nozzle in). The manual says "Prise it off". Well this one wouldn't "prise" off. After fighting with it for a very very verylong time i decided to use my brain. I attached 3 pairs of vise grips around the flange neck so that they were sticking straight up. Then i wrapped a rope around all three pairs and attached an engine hoist to the rope and started jacking. I would jack a little and tap on it with a hammer jack some more, tap and so on. After almost pulling the back tire off the ground and scratching my head i left the tension on the flange and kind of bounced on the trunk and BAM! it popped off. Then i did a little dance.

The tank was/is nasty. I put a gallon of acetone in it and shook it up and emptied it out and all sorts of shhh came out. Long story short i'm gonna keep rinsing it with acetone until it's clean again. then probably coat it with sealer unless someone else has a better idea.

RE: 1974 XJ12 Chevy 350 conv.
 

You are doing it correctly.

RE: 1974 XJ12 Chevy 350 conv.
 

Hi Michael

Congratulations on your new purchase. You got a very good deal.
Typically when I remove the filler cap, I don't have to pry on anything. The menthod that I most frequently use is first removing the screws, then the vapour line, and then use a large pair of channel locks to make the cap rotate from side to side, not up and down. This will break it free from where it has been sitting all those years. Then a rocking motion back and forth will help to get it up and out of the car.
Some of them are really tough. For those I have made a tool to go on the end of a slide hammer to help pop it out. I never touch the paint at all.

Something else you can try for removing the junk from the tank is muratic acid. You can get it at any hardware store for around $8 gallon. You have to add water to the tank before adding the acid. You can really dilute it, and let it sit overnight. Then add baking soda to kill the acid, and it's safe to dispose of.
Here is a link to that process. It's a VW site, but most of the text still applies.
http://www.ratwell.com/technical/Fue...storation.html

Then a tank restoration kit from either Eastwood or POR15 will have the tank ready to use. The kits are around $80.

Good luck with your project. The 74s are special, as there are a few things about them that are specific to that year. I have one that I'm using as a parts car....

David

RE: 1974 XJ12 Chevy 350 conv.
 

Hey thanks David i appreciate the info. I was thinking about POR 15 too, i'll check that site out. BTW, i tried to twist the flange to break it free but this thing was STUCK!! I did a little dance when it popped off though. Hopefully the other side will be a littleeasier.

My new problem is with the motor. I've been trying to get the motor to run before i re-install the gas tank just to make sure of no new problems (sticking the hose going into the fuel pump into a gas tank). Well long story short, i don't think i'm getting a hot enough spark because it won't fire. Remember this has a chevy 350 from a truckin it, not sure what year though (late 70's early 80's i assume). It's got the HEI distributor, thought it was the coil, changed it, still does it. Checked both coilswith DMM and they are both good. I think my coil isn't getting enough voltage, maybe someone can chime in that knows a little more than i. I'm getting 12.35V at the coil with the ignition "on" but it drops to 9.55V when i try to crank it (red wire). Shouldn't it get a steady 12+V when in the "on" positionAND when i try to crank it?
-Michael

RE: 1974 XJ12 Chevy 350 conv.
 

Micheal,

I'm not the best with Chevy motors, so all I can offer is a few comments.

First, have you checked the carbs for good fuel delivery? A light spray instead ofa flowing gush? Also, just try spraying some brake cleaner in the carb, and see if it will fire...
Next, check the battery charge, and the CCA rating. Fully chargedit should be almost 13V. On my 75 XJ12, I wasn't using a battery with a high enough CCA rating, and couldn't spin the starter fast enough. That helped, but I found the large braded wire behind the heat shield on the firewall was just about broken. Main problem with any Jaguar that has been sitting for a while is electrical connections. Get used to hearing, Disconnect, clean, lube, and tighten connections.

Most importantly, be very careful with remote fuel tanks. I did exactly the same thing, and burned a 87 XJ6 to the ground. A tiny spill here or there, and a tiny spark will lead to a big fire.

Lastly, I don't know if you are familar with the term LUMP. You'll hear it sooner or later referring to your car. It's basically a term for a Jaguar with a 350 engine meaning Less Upkeep, More Power. For the Jaguar faithful, it's a slap in the face. Personally I know the 350s are easier to find someone to work on them, and see it as another way to keep the car on the road..
There are a couple of forums with LUMP sections devoted to Jags with 350s.

David
EverydayXJ

RE: 1974 XJ12 Chevy 350 conv.
 

Thanks again! Yeah I know i'm getting fuel. The battery has plenty of juice, it has a battery charger connected to it as well, should have plenty of CCA. We got it to crank saturday morning and it ran for a good 30 seconds just keeping fuel in the carb (crunk right up actually). But 5 hours later when we tried cranking it again, nothing. It would just turn over. not sure if something came loose or what but i just don't think it's getting a good enough spark. The voltage drop at the coil during cranking is what concerns me. As soon as the starter turns over, the voltage drops from 12.3V to 9.5V.I think it should be a constant 12 but not sure. I'm going to try and run a wire straight from the battery to the coil to see if that solves the problem. What do you think about that?

About the LUMP deal, never heard of it.Some like it, some don't, i don't care one way or another. I'm not a chevy guy at all but the american motor was themain reason i bought the car, more or less for simplicity reasons. I'm not trying to restore it to factory specs, just trying to get it running and dependable. This is my first jag and i'm planning on doing all work myself and i appreciate all the help and advice from you guys

RE: 1974 XJ12 Chevy 350 conv.
 

Little update, i think i found the problem for no spark. I pulled the distributor cap off and the pick-up and mechanical advance were pretty nasty (rusty and dirty). Picked up a new pick up (no pun intended of course) and clean the advance, gonna try that this weekend. Had the ignition module tested, it was fine. Gonna put some heat sink on it before i re-install it. The vacuum advance has suction so i assume it's good too. Gonna set the timing if i ever get it crunk again. SBC 350 (carbed) timing should be somewhere around 6-12 degrees before top dead center (BTDC)right? That's what i keep reading anyway.