Hello all,

I type before you a guilty man. I have injured my freshly rebuilt 225 /6. The car is a 73 Scamp. Bought the car 7 years ago from the original owners. Odo was broken so mileage unknown. After 5 1/2 years of cruising about town it developed a rod knock. Time to rebuild. The shop I went to did a great job mechanical wise. Pumped out 235hp on engine dyno. I was happily broke. Did an oil change a week ago. Engine currently has 3965 mile on it. (gauges were replaced) This was to be 3rd oil change. But recently at a cars n coffee event a fellow Mopar owner suggested that I try a different oil filter. Instead of a WIX 51068 that was on the car. Change to a WIX 51460. Reason, it's taller, narrower an offered more clearance to work. Mulled it over then installed the 51460. Started it up , ran fine, cruised the town again. After couple weeks during start ups I heard a grinding sound. First I checked flex plate bolts, tight. Restarted again, grabbed a wood dowel and listened to the internals. Rod knock. My heart, head and wallet sank. I'm pulling the engine this weekend to survey the damage. Haven't torn down an engine in decades. But since I hurt it I should repair it.

Questions,
Would the difference in oil filter height cause a no/low oil condition on start up? The stand pipe is approx. 2" below top of filter
Hoping damage contained to just rod bearings. But what else should I be looking for?

I don't think the filter size you chose (or that bypass valve difference) caused your rod knock, but I don't think that 51460 was quite a wise choice.

51460 specs are here. The advisable long filter (the up-to-'72 filter before the shorter 51068-type was introduced by Chrysler for certain space-constrained V8 engines, then standardized across all engines), the 51515, is here. The mount interchange looks okeh (gasket dimensions differ by a couple mm, not likely to be problematic).

But I don't like the large difference in the bypass valve between the two filters. That's far enough off spec that I'd hesitate to use the 51460.

I have heard rumblings that Wix filter quality is no longer what it used to be. I do not know how true that is, nor to what extent.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

The distance to the standpipe is not likely the issue. Plenty of our Slant 6's are running or have been run for long periods of time without the stand pipe at all.

Did you happen to have new connecting rod bolts installed? Like the ARP bolts. If so did they resize the big end of the rods afterwards?

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

It sounded to me like the question/concern was whether the top of the filter might be too close to the standpipe, potentially blocking it. I do not think that is the case, though.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

235 on the dyne is worth crowing about.. at least you can tell us what you did to accomplish that...

The OP was running 51068, which is 1.47" shorter than the 51460 recently installed. The 51068 is the OE filter for that '73 mill, so unless the Builder installed an old standpipe, then put the shorter 51068 on anyway(never tried it to see if possible).. that would be the only potential F-up that would've starved the mill for oil. And that would not be on the OP. I suspect unless that's the case, the cause lies elswhere, the higher pressure bypass should be a non-issue on a fresh engine with plenty of pressure.

To the OP, is the standpipe ~2" shorter than the 51460, or the 51068??

Do you have an aftermarket oil pressure gauge with numbers on it? If not, you need that for any kind of performance engine. That would have told you right away IF the oil filter was not performing properly right when you installed it. I seriously doubt it was the filter, but it is possible.

235 HP is quite good, so you must have done some nice head porting, CR, and good cam choice and installation. Too bad this happened and let us know what you find when you get into the engine.

FWIW, I will never run a standpipe on a performance Slant. I had an oil pressure drop issue on one of my hotted up engines and removing it fixed the drop in oil pressure at high RPM. I have only run standpipes a couple of times and have other engines that went 200k with no standpipe. They give some insurance, but I believe they are restrictive when you run loose bearing clearances and have larger oil flow demands.

Lou

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Home of Slant6-powered fun machines since 1988

Given the construction details of the '63+ standpipe with inbuilt check valve, it does not surprise me you saw a significant pressure drop at high RPM with high oil volume demand. The '62 no-valve standpipe is surely much better, and I bet a skilled machinist could make an even better standpipe, and the inbuilt standpipe in the Wix 51806 (and similar) is of a totally different design which I have a hard time imagining causing much of any flow restriction.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Thanks for the year-break info on the standpipe, Dan. I am glad you agree the 63-up valved pipe is potentially dangerous. It looked like a very small hole to me.

Peronally, I still see no reason to run a pipe at all given the modest wear on my engines under severe use over 3+ decades with no standpipe (aftermarket pumps). I expect modern oils and filters (since the 1980s-1990s?) make this feature unnecessary. What a performance engine needs is clear flow. FYI, I do not intend to start a debate over this, but am just stating my personal behavior, belief, and experiences on this matter.

Lou

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Home of Slant6-powered fun machines since 1988

In the unusual use case of very high revs and very loose clearances, yeah, it could be. Millions of Slant-6 engines not put to those stresses racked up many, many years and miles with the valve-equipped standpipe, though.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Totally agree. It was really over 5000 RPM and with fairly looks crank clearances that I saw the problem.
Lou

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Home of Slant6-powered fun machines since 1988

Excuse the delayed reply. Mama's Magic Bus needed brakes. Happy wife yada yada. Won't pull engine till after the Holiday weekend.

Dan your "I don't think that 51460 was quite a wise choice." hit like the end scene in Indiana Jones Last Crusade. The villain did not choose wisely either.

Killer6, the standpipe sits 2" lower in the 51460. Could that cause a 'dry oil pump' situation on start-up?

Dart270, we installed Auto Gauge gauges. Replaced the dash panel with a 6 gauge cluster. Oil pressure was/is 35+

Engine specs,
Cam grind #218 108LSA Duration @ 50 226 degrees Exh & Int lift .440" Int CL 104 Exh CL 112
.045 over bore
3.445 forged pistons & forged con-rod
Block zero decked
Head cleaned-up .005
Head ported (alot)
Exh valve 1.44
Int valve 1.70
Compression 10.75:1
Aussie Speed low rise 4bb intake w/1" tapered spacer
Aussie Speed headers
Exh Y piped to 2.5" to MF muffler to 2" turndown under bumper
Holly 390 4bb w/metering block Jets 51/59
91 pump gas

Dyno run Torque 287.7 @ 3,500 Hp 233.5 @ 4,900

Those are great numbers considering how small the cam is! Great job! You must have very good head work and are to be congratulated! Well done.

_________________
2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

No. The standpipe works together with the filter's own antidrainback valve to keep the filter full of oil after shutdown so it needn't be refilled on startup before the bearings get their oil.
If so, then the failure was touched off by something other than loss of oil pressure. Could be improper assembly, could be one or more faulty parts, could be plain old rotten luck.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

I only ask because I did this and the new bolts distort the rods/caps at the parting line. I burnt a bearing and broke a rod, destroying the engine completely.

_________________
2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6