'68 318 to carbed Magnum 5.2: Check my checklist

[ValiantOne]

Well, given that I'm down here in South Florida, I rather like the idea of reliable R134a. That, and I swore off converted compressors after foolishly beating my head against countless Delco A6s in a pair of '70s Lincolns I had (prior to the Chinese aluminum drop-in units). Granted, the A6 is the worst offender (and one of the many things that puts me off GM), but still.

The RV2 that came from the car was a 1980's unit with questionable history, so using it wasn't necessarily the best idea either. Believe me, I'd jump on a modern drop-in RV2 replacement, but it's not as if such a thing exists.

I will say this though: The Sanden is getting it's label ripped off and the housing painted black. Heck, if I can find a reproduction Mopar label for an RV2, I'll stick it right on the housing.

-Kurt

P.S.: Be careful doing the rear seal on your Valiant's engine. Easy to tear it between the crank and the block. Not difficult though, given some finesse. You might find a rope seal back there; can't recall what my '68 block had.

When rebuilding the Valiant's AC I stuck with the V2 compressor and upgraded to R134. I installed a new parallel flow condenser, all new lines and also rebuild the compressor. It worked "okay" but not really stellar. Unfortunately the carbon pack shaft seal on the compressor (brand new one) gave up the ghost about 18 mos. after installation and the system has been dead ever since. I am going to a Sanden as well, but as I am going full on Magnum I'll be good to go.

The seal on the Val turned ugly. Had to remove the crank. Found a bad rod bearing........... Grrrrrr.........

Glad yours is running. Looking forward to seeing the video!

Best,

CE

 

[cudak888]

When rebuilding the Valiant's AC I stuck with the V2 compressor and upgraded to R134. I installed a new parallel flow condenser, all new lines and also rebuild the compressor. It worked "okay" but not really stellar. Unfortunately the carbon pack shaft seal on the compressor (brand new one) gave up the ghost about 18 mos. after installation and the system has been dead ever since. I am going to a Sanden as well, but as I am going full on Magnum I'll be good to go.

The seal on the Val turned ugly. Had to remove the crank. Found a bad rod bearing........... Grrrrrr.........

Glad yours is running. Looking forward to seeing the video!

Best,

CE

You'll find that the Sanden for the stock Magnum accessory bracket is not the same as the ones generally offered for conversions - and even the one that BPE specifies for the conversion kit (Sanden 4456) is about half an inch shorter than the one that everyone is accustomed to.

Neighbor has a Dodge Dakota with a Magnum 4.7 - the Sanden on that is its own animal as well (reminds me of a cross between the common 4-ear Sanden and the three-ear '80s Sandens such as the one that was on the '89 van engine. From what I've been able to seel, Dodge had Sanden build compressors in shells designed specifically for Chrysler OEM applications.

Sorry to hear about that rod bearing. Any major damage on the crank?

-Kurt

 

[cudak888]

Shopping list is getting shorter:

• Sanden CP7H13 U7312
• Kickdown from 4-barrel 360 (Thermoquad kickdown would work)
• Fan shroud (Mopar #P2998326)
• 18" clutch fan (from junkyard)
• Mopar air cleaner
• Possible change of spark plug wires - the Accel ends do not fit tightly in the Borg-Warner distributor cap

Sacrificial anode radiator cap is on its way, along with a '70-style dual belt squareback alternator.

-Kurt

 

[cudak888]

The downpipes had not been completely welded when I first started the engine. Finished my semi-booger welds tonight:

That said, I have a bit of a quandary going with the ball-end Walker exhaust manifold connectors. These things have thick flanges with no bevel/chamfer at the flange:

(FYI, the pic shows the 2.5" versions - they won't work if you're trying to cross-reference part numbers. You need the 2.25" version, P/N #41725 for the large-flange Magnum manifolds).

Unsurprisingly, I don't have the ball ends centered on the manifolds so that the pipe clears the torsion bar with ease (no matter how centered it looks here, it isn't):

This said, can I rely on the flat flanges to seal the ball end, even if the pipes are not parallel to the manifold? They seemed to be nice and tight during the engine startup, but I can tell you that you'd never hear an exhaust leak running it with those short downpipes.

Should I get a pair of chamfered 2.25" flanges (like the one below) and replace the flat flanges? Honestly, I'm a bit paranoid about getting an answer on this one, for it looks like I've run into yet another one of those unusual little questions that the internet has never answered until now. Seems like everything has beveled flanges except these things from Walker.

-Kurt

 

[ralphie361]

I used the same flanges on my dart with hemi manifolds, and I'm using the flat flanges. After about 500 miles, one started to leak. I loosened it and retightened it, went away for a while, but it's still barely leaking. I'm probably going to rebuild my exhaust soon anyway, so I'm too concerned, but you are probably thinking right on the flanges.

 

[cudak888]

I used the same flanges on my dart with hemi manifolds, and I'm using the flat flanges. After about 500 miles, one started to leak. I loosened it and retightened it, went away for a while, but it's still barely leaking. I'm probably going to rebuild my exhaust soon anyway, so I'm too concerned, but you are probably thinking right on the flanges.

That settles it, along with Trebilg's advice in this thread:
http://www.forabodiesonly.com/mopar/showthread.php?t=330681

Off come the flat flanges, and on go a proper set with chamfered/beveled edges.

-Kurt

 

[cudak888]

Almost finished up my "too cheap to pay an exhaust shop" booger-welded exhaust system.

Not really too concerned that it might not flow as good as it could. I just care that it works and saves me a few hundred dollars.

Both pipes are just hanging from the Walker flared-end collectors in front, one lower than the other. I don't want to cut or measure the collectors for cutting just yet, as I'm waiting to buy a pair of proper beveled collector flanges from Treblig and install them at the same time I button everything up.

-Kurt

 

[cudak888]

Point #1: I hate Daylight Savings Time. Might as well work on the car at midnight.

Point #2: I really like these exhaust flanges. Thanks, Treblig!

Point #3: If all goes well on the weekend, perhaps those flanges will become part of my exhaust, permanently.

-Kurt

 

[sireland67]

Love low buck stuff, and yes daylight saving time sucks.

 

[ValiantOne]

Actually we are back on standard time, which sucks! In fact I was installing exhaust manifolds from Trebleg last night in the dark..........

 

[cudak888]

I was installing exhaust manifolds from Trebleg last night in the dark..........

Got you beat. Today, I tried welding and installing my pipes in this evening...in the rain.

Of course, it was neither nighttime nor evening when I first started.

It looked promising enough in the early afternoon. Flanges went on nicely, welds couldn't have been better, and this is what I call one hell of a perfect fit seeing that I figured out all the bends on this redneck exhaust without ever lifting the car up an inch, and pretty much threaded it through the bottom of the car flawlessly:

Then I welded on a small extension to make up the gap at the muffler (you can see it in the first photo), and installed the left pipe.

Turns out I was a bit too well tucked in. The straight section of 2.5" pipe pulled up just a quarter inch from the floorpan. Not enough for my liking.

After cutting and fooling with the fit at the back, I put it back in - and this time, I angled it wrong. So I closed up for the evening. Grrrrrrrrr.

-Kurt

 

[cudak888]

Today, I got smart. I put the final section of 2.5" pipe in each muffler, and mitered it until it matched the pipe in front of it. With a few crosshairs placed on the pipe, I was able to get each section welded up perfectly.

That, and the USPS surprised me by delivering my 2.5 OD to ID exhaust band clamps just as I was finishing up the second pipe. Score!

But I don't have a photo of any of that (boo). I don't even have a photo of the brand-new Edelbrock 1406 I dumped on top of it (double boo). But I had barely enough fuel in the Summit - just before I pulled it - to record just a bit of what the new exhaust sounds like before it shut off. Please excuse the lens flares.

[ame="https://www.youtube.com/watch?v=vF3DycKpiz0"]satellite start - YouTube[/ame]

Not as quiet as I had expected...

Also had to get a power steering cap from the auto parts store. The original cap's seal was a goner - the P/S pump was a geyser of fluid on both of these startups.

-Kurt

 

[cudak888]

At last, the carburetor that the Mopar gods intended in the first place. Note how much better the throttle linkage and return springs sit.

Spent the majority of the day trying to figure out why it wouldn't stay running - and only then realized that the Edelbrock (first time I've had one) has a 1/4" port in the back for power brakes, and it was gaping open!

Goodness knows I thought I heard a vacuum leak.

That said, I plugged it, and the engine started right up. Two problems:

1. The steering is locked solid. I must have installed the pump cam ring the wrong way. That would also explain why it's spitting fluid.
2. The engine idles good, but there's a valvetrain noise coming from the right side of which I'm quite worried about. Not a healthy sound.

It'll all have to wait though. I consider it a victory that I got it running, and will bask in that victory as I spend a bit of time this week plumbing the Summit carb on my '71 Mustang.

-Kurt

 

[ValiantOne]

Today, I got smart. I put the final section of 2.5" pipe in each muffler, and mitered it until it matched the pipe in front of it. With a few crosshairs placed on the pipe, I was able to get each section welded up perfectly.

That, and the USPS surprised me by delivering my 2.5 OD to ID exhaust band clamps just as I was finishing up the second pipe. Score!

But I don't have a photo of any of that (boo). I don't even have a photo of the brand-new Edelbrock 1406 I dumped on top of it (double boo). But I had barely enough fuel in the Summit - just before I pulled it - to record just a bit of what the new exhaust sounds like before it shut off. Please excuse the lens flares.

satellite start - YouTube



Not as quiet as I had expected...

Also had to get a power steering cap from the auto parts store. The original cap's seal was a goner - the P/S pump was a geyser of fluid on both of these startups.

-Kurt

Woot woot! Sounds good. Congrats. Now some kitty litter for that PS fluid!

 

[Aaron65]

Is it possible that a rocker is hitting your new/old valve covers, like at a baffle or something? Just throwing that out there. It's always best to think positive...

 

[cudak888]

Woot woot! Sounds good. Congrats. Now some kitty litter for that PS fluid!

You said it. That, or some cardboard boxes.

Is it possible that a rocker is hitting your new/old valve covers, like at a baffle or something? Just throwing that out there. It's always best to think positive...

Not sure. There is a baffle on both covers, as seen here. Excuse the sludge.

Never heard of Magnum rockers hitting an LA valve cover before.

-Kurt

 

[cudak888]

Pulled the Saginaw PS pump this evening and flipped the cam ring around.

Would have been easy, but the van/Ramcharger two-piece P/S bracket has one drawback: You have to loosen the bracket to allow the pump's rear stud to slide out of its rear hole. The result? Water pump starts leaking. Probably seeping between the threads too, even though the threads have been shellacked.

At any rate, I'll be able to jack it, start it, bleed the steering, and then get to work on the valvetrain noise.

-Kurt

 

[cudak888]

Not much to report tonight other than I burped the power steering. Works great now.

Engine is still idling very high - haven't really touched the carb, so there's not much I can fault it for.

Almost certain the noise is partially an exhaust leak, but not isolated to it. We'll see.

-Kurt

 

[cudak888]

Opened up the valve cover today and did a compression test on the entire right bank. 150+ PSI on each cylinder. Nothing wrong there, so no Miss Valve hooking up with Mr. Piston, thankfully. Granted, a leakdown test would be a better indicator, but hell with that - I don't have the tool.

I'll say one thing though - this thing does NOT starve for oil. I can idle my Valiant's 225 with the valve cover open and don't need anything more than a cardboard box, but this thing shoots oil through the pushrods as if it were at war with the valve cover.

That said, I found that the fifth rocker in from the front was just a tad looser than it should have been - probably had a bit of load on it when I tightened it initially. Tightened the crap out of every rocker bolt, closed up the cover, and...

...perfection. This thing runs so smooth you could build a house of cards on the intake manifold (if it wasn't for the fan). I've heard that the HEI conversion improves the idle considerably, and the 3.9's timing chain tensioner helps keep the distributor timing accurate as well - but I've never heard a specific report of how the two work together. Flawless seems to be the word.

Keeping it running is another matter entirely. I don't have the choke hooked up, and it's quite apparent that either the Edelbrock or this engine is very picky about having the perfect A/F mix or it won't stay running.

I don't have the alternator (a squareback I found on Craigslist) hooked up to the pulley system yet (still need that compressor), so I'm not sure if there will be any output off the field terminal if I wire it up as-is. Electricity isn't my strong suit (yet, anyway).

-Kurt

 

[sireland67]

Glad you got it going, please get rid of that plastic fuel filter for a good metal one.

 

[cudak888]

Glad you got it going, please get rid of that plastic fuel filter for a good metal one.

Soon as I get to see what winds up in there when the tank runs dry.

Any recommendations for something that isn't a Chinese piece of crap?

-Kurt

 

[goldduster318]

Soon as I get to see what winds up in there when the tank runs dry.

Any recommendations for something that isn't a Chinese piece of crap?

-Kurt

For fuel filters, you could really just use any name brand...Purolator, Fram, AC Delco, Wix, etc.

I think what would really be nice is one of those feed lines that attaches to the carb, makes a 90 and then comes straight to the front.

Basically this
http://www.summitracing.com/parts/edl-8134
plus
http://www.summitracing.com/parts/sum-220769/overview/

You can get all the same stuff in either chrome/silver or black if you want as well. With the way rubber fuel line gets hard and cracks today, I try to keep as little as possible in the system.

Really like this build.

 

[cudak888]

For fuel filters, you could really just use any name brand...Purolator, Fram, AC Delco, Wix, etc.

I think what would really be nice is one of those feed lines that attaches to the carb, makes a 90 and then comes straight to the front.

Basically this
http://www.summitracing.com/parts/edl-8134
plus
http://www.summitracing.com/parts/sum-220769/overview/

You can get all the same stuff in either chrome/silver or black if you want as well. With the way rubber fuel line gets hard and cracks today, I try to keep as little as possible in the system.

Really like this build.

Last time I used one of those chromed fuel line elbows (on a Holley 4160), the nylon crush washer took on the shape of the nut. Three months later, I tried starting up the car, only to have gas sprayed over the entire engine bay and hood. Not sure the chromed surfaces are smooth enough for a thin crush gasket either. I'd rather not experiment with them.

I have faith in the Goodyear Instagrip synthetic hose. Marvelous stuff, have yet to find any of it dryrotted in 10 years, and I can also use it as PS hose. Just a pain to get it.

-Kurt

 

[sireland67]

Summit sells the proper fitting to go from the carb, to 5/16 flared fuel line.

Buy a 5/16 brake line, they have the fittings on both ends, bend the line over a large diameter piece of pipe.
If you are super cheap and do not have a piece of pipe, you can buy a 1.5" ID PVC coupler for about $1.00 at the local hardware store and make decent bends using it.

Put the fuel filter down by the alternator where the factory did it.

 

[cudak888]

Summit sells the proper fitting to go from the carb, to 5/16 flared fuel line.

Buy a 5/16 brake line, they have the fittings on both ends, bend the line over a large diameter piece of pipe.
If you are super cheap and do not have a piece of pipe, you can buy a 1.5" ID PVC coupler for about $1.00 at the local hardware store and make decent bends using it.

Put the fuel filter down by the alternator where the factory did it.

I found factory-style SBM fuel lines for the Carter AFB on eBay:
http://www.ebay.com/itm/68-69-70-71...ash=item257d41db45:g:T1EAAMXQM0FRerXZ&vxp=mtr

For $18 plus the cost of the fitting to the Edelbrock AFB, it's easier and more reliable to go this route. Might need to be massaged a bit to clear the choke, but nothing major.

-Kurt