Sub-$1k Manta A project

[germanautoaddiction]

I tend to change my mind a lot about my vehicular situation--at the start of last weekend I told myself my next vehicle would definitely be a cheap old Honda CB motorcycle, but my '81 5 Series daily driver's been giving me problems, so I started checking Craigslist for a decent 320is to use as a cheap daily... and then I checked out eBay and 10 hours later I bought a '75 Opel Manta (with only 73,000 miles) instead.

It's a local SoCal car, so the only rust is right on the surface, easily sandable when I paint it either this year or next. It had been sitting for a few years, but somehow started up and idled nice and smooth on amazingly old gas. Didn't make it all the way home though--whenever I'd try to give it more gas it'd sputter until I pulled over and let it idle for a bit. Then I was able to accelerate up to about 20mph again until it started to sputter again. I changed between the shoulder and back into the lane again like this for several miles, but it was starting to get dark so I called AAA for a tow. My room mate and I reasoned through the issue and I decided to replace the fuel filter and drain/refill the tank w/ good gas, and clean the injectors if that all didn't work. So I replaced the filter, had a nice gasoline bath as I drained the tank, and put some Gumout in with a few gallons of gas. After cranking it over long enough for the gas to make its way up to the engine it fired right up, no sputtering or anything! I drove it around the block a couple of times and it's running like a champ, easily chirping tires a bit 1st and 2nd w/out really trying. Now I just have to register it and do some suspension work and it'll be good to go.

Anyway, here are a few pics from last weekend the day after I brought it home:





The interior's in pretty bad shape, but I've got some upgrades waiting in the garage to take care of a few things, and an idea to replace the torn up back seat...

[BQS4]

I saw this car on Craigs list, thought it was a good buy, just too far for me, but, glad to see someone with an eye towards putting it back on the road got it. Congrats! Keep us posted

[Aardvaark]

I second on it looking like a good buy. The dirty tank and plugged filters are a common problem on the Opels that have set unused for a long time.
The '75 injection cars have been popping out of the woodwork lately.

[ephillippe]

Congrats on the Manta! Sounds like the same situation I had when I got my 73 Manta, just do the basics (You already did the gumout) new plugs/wires, new air filter, good gas, get some good synthetic oil and tranny fluid in there - and most importantly use it as much as you can, all of my old cars get weird after some non-use even though they are in good shape all around.

[heimue]

Originally Posted by ephillippe Congrats on the Manta! Sounds like the same situation I had when I got my 73 Manta, just do the basics (You already did the gumout) new plugs/wires, new air filter, good gas, get some good synthetic oil and tranny fluid in there - and most importantly use it as much as you can, all of my old cars get weird after some non-use even though they are in good shape all around.

I'm sure this has been discussed to death before, but I do not recommend the change from "regular" to synthetic fluids - specifically in an "older" engine. The engine / gear box / rear end has not been engineered to use the modern stuff, and it's working best with fresh regular oils, like they were around in the early 70's. They regular stuff got better formulated with time (which is fine), but do not expect any advantages from synthetic oil in your Opel.

Anyway, nice find for an under-1k-manta!

Dieter

[germanautoaddiction]

Originally Posted by ephillippe Congrats on the Manta! Sounds like the same situation I had when I got my 73 Manta, just do the basics (You already did the gumout) new plugs/wires, new air filter, good gas, get some good synthetic oil and tranny fluid in there - and most importantly use it as much as you can, all of my old cars get weird after some non-use even though they are in good shape all around.

That's exactly the plan--although the plugs look brand new, so I think they were raplaced just before I bought it; wires look fairly fresh too.

I've been debating the point you and Dieter have brought up about fluids. In the past I've tended to use synthetic whenever I don't know what the previous owner used, since I've always heard you can always switch to synthetic from regular, but if you change back to regular from synthetic the seals will dry out, or something to that affect. I don't know if this is proven fact, but it's been my rule of thumb with previous cars. But at the same time, yes its parts were designed to work with the fluids that were around at the time, so I'm not sure I want to mix the high-tech fluids w/ low-tech mechanicals... Anyone have experience using synthetic blend as opposed to full synthetic?

[timemachine]

Nice car! Congratulations and good luck on your project! You'll have a blast with your Manta.

Originally Posted by germanautoaddiction I've been debating the point you and Dieter have brought up about fluids. In the past I've tended to use synthetic whenever I don't know what the previous owner used, since I've always heard you can always switch to synthetic from regular, but if you change back to regular from synthetic the seals will dry out, or something to that affect. I don't know if this is proven fact, but it's been my rule of thumb with previous cars. But at the same time, yes its parts were designed to work with the fluids that were around at the time, so I'm not sure I want to mix the high-tech fluids w/ low-tech mechanicals... Anyone have experience using synthetic blend as opposed to full synthetic?

I don't tell anyone what they should do (least of all Dieter!) and non-racers would have to agree you're fine with conventional oil all around since that's what the motor was designed for like you say. Some folks even do their own blends, but not being a chemist, I have no idea what kind of formulation you'd actually wind up with.

Based on my experience, hard driving days on long road trips (and conversations with people who know better than me), I've had very good success with conventional crude Shell Rotella 15W-40 in the crankcase (to address the ZDDP and flat tappet risks of modern off-the-shelf crude) and a Purolator 10028 filter.

Redline MTL (all-synthetic) goes in the manual gearbox and Redline 75-80 goes in the rear. There was a noticeable improvement in shifting in my case, and, like the rear end, the 4-speed takes about 2.5 pints. That's not even a Big Gulp's worth of oil, and since they're rarely changed, it helps me buy into the case for synthetic for those uses. (The gearbox and rear on my car were original and unrebuilt when I put in the Redline, though the car had only 32K on the clock. Neither has leaked a drop in well over three years using Redline and all is quiet.)

But to each his own and I'd never argue with crude. My Toyota mechanic swears by Mobil1 gear oil for the diffs on my 4Runner even if the old crude is 10 years old.

But anyway, the Rotella oil and Puro filters are available most everywhere for cheap (which keeps you consistent) and you can get Redline through a local dealer or through the mail.

Can't wait to hear more as your car comes along.

Jim

[ephillippe]

Forgot I would open that old can of worms....I personally like the detergents in the synthetic cleaning out the old gook (I also usually run an engine cooler with Syn, and got an extra mile per gallon on my V8 Valiant!) Its satisfying to see it get dirty quickly a couple of times while its cleaning then start staying a nice gold color for 4-5k after that

That being said, both my Manta and Valiant are in pretty good shape, so theres no blowby so far....I would say just change it regulary whatever you use and you'll be cool!