Hey guys, I am new here but have driving my Swinger with a 225 for about 12 years now and have put 126,000 miles on it since I bought it, which is more than the original owner put on it. When I first bought it , I was distressed because after being started up cold, the would be a definite knock in the engine, just about anyone would think this motor was done for. I certainly did. I had lamented that the guy had it warmed up already or must have put something in the crankcase to keep it from knocking just long enough to sell it. But it never "knocked" under a load, ever, only at idle and only when cold. And here I am 12 years and 126,000 miles later. Obviously it means nothing. But to someone who doesnt know, it sounds like a swan song in the morning.

How do I know? Well aside from the mileage, I just had it rebuilt about 8000 miles ago. It was getting to the point where it was using a quart of oil with every tank of gas ( even though strangely, the car didnt smoke) instead of a quart every 1500 miles or so like in the beginning when it only had 76K the original owner put on it. I was coming up on 200k total miles so I figured it was time.

I pulled the engine and had the rebuild done by a a speed shop. Not a run of the mill machine shop that fixes enines for farmer Browns tractors and his pickup truck, mind you, a speed shop. Theres a difference that goes beyond the price, you get what you pay for. Bottom end is blueprinted and everything was magnafluxed , reconditioned and resized. I had them flow the head ( another difference, run of the mill machine shop doesnt have a flow bench) shave .100 off the head and put oversize valves in. Used a better than stock, yet still somewhat mild cam, tube headers and 600 edelbrock 4 barrel. I really spared no expense having this engine re built, a bit over 5 grand, more than most people might want to spend on a slant 6. It probably makes about 220-230 hp, and over 300 ft lbs. About what a good 318 will do, but for about twice the money, which is why most guys wouldnt do it.. But what Im going for here is novelty, something different than the V8s that everyone else has in their classic car. It really attracts more attention at car shows with the hood up because its usually the only inline 6 of any type there, and the carb, manifold and headers add to the the wow factor. People arent used to seeing inline sixes anymore in a classic car culture dominated by V-8s.

Its great to drive as it is interesting and different to look at though, and I guess that makes it worth the money. It jumps hard off the line and spins up to 6 grand quickly,effortlessly, and quietly. On the highway it will just run away from most anything. Runs like silk at any rpm, as if it had a computer and fuel injection (like the 4.0 in my Jeep) rather than breaker points and a carb. Its better than the 4.0. It will really smoke most 4 cylinders light to light, including the tuners with their Honda v tecs that they worship so much, and it will run right with a lot of V6s too. Since break in, it isnt using a drop of oil, 5 quarts go in a 3000 miles later, 5 quarts come out and the old oil actually is not that dark on the dipstick. No matter how hard I drive it between changes. isn't that what you would expect a a high dollar speed shop? I havent been to the track yet but Im pretty sure it would break into the 14's without too much trouble. I have had a passenger with a stop watch time 0- 60 in an average of about 7.5 seconds, and it doesnt run out of power at higher speeds. On the highway I can pass very easily and I can even deal with the occasional butt wipe that wants to play cute and speed up when I try to pass. In fact would really say that off the line acceleration, good as it is, feels like nothing compared to the top end performance which I estimate to be around 130, turning at 6 grand. The car is amazingly quiet and stable at speed. wind noise is louder than the the engine even with the windows rolled up and is , in fact, all you hear. I love this engine and have no complaints at all.

But guess what, that cold knock is still there, a noise that I stopped losing sleep over a long time ago. It is apparently a common characteristic of a slant 6, to make this funny noise when idling cold....

An oil filter with a good anti-drainback valve will stop the start-up rattle. I'm glad you're happy with your car.

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Joshua

Hi, and welcome to the forum, Dburt164!

If you have a high-volume oil pump as part of your engine build-up, it may not have been fitted with a standpipe to fit inside the oil filter, so the solution is to use a filter that comes with an internal standpipe. Given some time, the oil will drain back via the central hole in the filter to the oil pan through the all tiny passages that exists because of the clearances between the engine components. When the filter is equipped with an internal standpipe, that runs through the filter from just inside the threaded part and almost to the domed end, you can turn an oil-filled filter upside-down without spilling much of the oil inside.
The drain-back valves prevent oil from coming out of the small holes in the filter, and the standpipe prevents it from coming out in the central hole. That means that your oil filter always contains oil, so when you start up your beloved slantsix engine with an oil filter fitted with a standpipe, you have almost instant oil pressure. No more rattling at startup, longer life for your engine! Some examples of first class oil filters with an internal standpipe:

NAPA Gold #1806, Wix #51806, Baldwin #BT-216, Purolator #L30137. Cummins Fleetguard #FL3685

NAPA and WIX is the same filter. Stay away from FRAM filters! (use the search function for reasons)

These filters have all the same dimensions and specs as the regular filter, except it contains a built-in standpipe to keep the filter full of oil after shutdown.
This is originally an oil filter intended for industrial & construction equipment engines. If you have trouble finding them in a catalog, many of these filters are made for farm- and construction equipment using a Perkins engine, including Volvo Equipment, Caterpillar and Massey Ferguson. If you want some more exotic examples of oil filters with internal standpipe, how about Ferrari Dino?
Using a high quality synthetic oil is also recommended, many members use Mobil1 0w-30, personally I use Red Line 10W-30 in the summer, and 0W-30 in the winter, on a stock 2 bbl engine.

I hope this may contribute to solve your problem.

Olaf.

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Aspenized

Well, that really has me scratching my head because I do have a standpipe in the oil filter mount. also, I do have a mechanical ( oil line) gague that shoots up to 40 psi immediately. Dont think that oiling or drainback is a problem. The noise continues a lot longer than it would take pressure to build up throughout the engine. And if I put it in gear rightaway and drive it, even cold, no noise at all under load, period. Only when idling cold.

I thought maybe it had something to do with either the mechanical lifters or a piston slap, which isnt so bad as it sounds, piston slap is actually pretty common on old style engines. I lived with this very noise for well over 100,000 miles of driving. I think its worth noting that a slant has some hard metal in both its block and heads as well as its internal parts, with a very high nickel content. The guy at the shop said they dulled a few cutting tools while machining my parts, and that the average engine like say, a Chevy 350 (the example he used) was made of butter compared to what I have. It is a '72, so it would have all the goodies like forged crank, etc. which they did reuse. They said my crank and rods were all in good shape with no issues and requiring minimal work, and that my main problem prior to the rebuild was that the compression rings were gone, those being the one weak link with all that hard metal all around. All the main and rod bearings were still ok, although they did of course replace the bearings! They also told me that if I had been willing to live with the oil consumption and the lack of power, I could have gone another 50,000+ miles, as all the rotating parts were fine..

Well Dburt164, it sounds like you have the good parts already. I would recommend you to take the time to read the articles on cranks and blocks in the article section, as well as the massive information on SL6 engine building in this link to Best of Doctor Dodge in the FAQ at the start of the engine section. (BTW, all red text are clickable links) It may give you some insight regarding modifications that may have been unknown to you and the machinists that built your engine.
You can also use our excellent search function to find other posts on the subject, there are more than 100.000 posts in the engine section alone!
Keep us updated on your findings!

Olaf.

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Aspenized

I've run into some piston slap issues with this engine. Not as bad as SB Chevy's to be sure. I've seen 350's come in with all the skirts in the pan.

Cold, your going to find it, especially with forged parts. Just keep the revs low during warmup. Be patient with it, and it will run a long time, as you've found.

I still have pump up issues. I use High grade WIX from the NAPA Gold line with internal standpipes and anti-drain-back, and still hear a bit of futzing about by the engine parts. The pressure is taken off well before oil is pumped to anything vital. Perhaps if we put the sender closer to the parts in question we could get better information!
Oil travels last to the top of the engine. At the back rocker shaft bolt. Now where could we take that pressure off to feed a sending unit... That would be more useful information than the outlet of the pump!

2¢

CJ

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Part of Tyrde-Browne Racing