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468 BBC oil pressure problems
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William Jones
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Joined: 30 Jan 2006
Posts: 822
Location: Lake city, FL
28514.86 points


1971 Ford Mustang

PostPosted: Tue Apr 07, 2015 9:47 am    Post subject: 468 BBC oil pressure problems Reply with quote

I just finished putting this together for a friend. Upfront I will say he had the crank turned. 020/ .020 by Napa and after measuring it I think the guy was on crack the journal were all over the place and not quite round. The bearing clearances on the mains came in .00175 to .0025 wasn't happy with it. But he was dead set on going with it. The rods were .002 to .0025. Rod side clearance was .018 to .020. The engine has a large dome and Iron square port heads , stock style rods with ARP bolts.

So we fire it up Saturday and let it run for about an hour sounds pretty good and oil pressure never goes below 50 psi. Yesterday I start it up to back it out of the shop and I was letting it warm up. When the temp started to come up the oil pressure went down from 65psi no big deal but it was a continuous slow drop in less than a minute, until it hit around 15 psi. The problem is if I give it gas it doesn't come up. No noises coming from the engine. So I shut it off for a few minutes then start it up fires up and has about 50 psi then slowly drops within about a minute. I had another job to do so I didn't really get to check anything yet. When I get home I'm going to pull the filter and make sure it didn't get a bearing. But it kinda seems like maybe I have a drain back issue or maybe a oil pump pressure relief sticking or a bearing issue. What you guy's think?

Bam

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92 LX 454ci Clevor 9.24@142.53 N/A
71 Mach1 454ci Clevor 10.16@134 N/A 3850lbs race weight "Lost in fire"
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af2
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Location: grassvalley, ca
71227.76 points


1933 Willys Coupe

PostPosted: Tue Apr 07, 2015 11:21 am    Post subject: Reply with quote

I hope you are using a Wix filter and not the orange one.

Filter first. cut open and see if it didn't collapse or full of ..............
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William Jones
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Joined: 30 Jan 2006
Posts: 822
Location: Lake city, FL
28514.86 points


1971 Ford Mustang

PostPosted: Tue Apr 07, 2015 9:26 pm    Post subject: Reply with quote

Well I cut the filter which was a K&N filter bearings are good had very fine mist of molly lube and metal common with fresh rebuild. Put a new filter changed gauge and fired her up 65psi cold and 58 hot idle increased to 70 when reved up. So I think I am out of the woods going to put it through a few more heat cycles and see what happens.

Bam

_________________
Take the horse out off the barn and let her RUN BABY RUN!!!!!

92 LX 454ci Clevor 9.24@142.53 N/A
71 Mach1 454ci Clevor 10.16@134 N/A 3850lbs race weight "Lost in fire"
03 Cobra Bone stock 12.42
68 Falcon 363ci 10.55@126 N/A
95 GT 363ci 11.08@118 N/A
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10sec.et
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Joined: 29 Mar 2006
Posts: 3473
Location: Houston,Texas
346658.74 points


1969 Oldsmobile Cutlass

PostPosted: Wed Apr 08, 2015 1:31 pm    Post subject: Reply with quote

if the engine is built with a lot of moly, i will change the filter right after cam break-in or after the first few minutes of run time.
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af2 wrote:
It seems we can look at our magical Balls and come up with a fix?

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clay
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Joined: 24 Nov 2002
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Location: South Carolina
318129.23 points


1972 Chevrolet Nova

PostPosted: Wed Apr 08, 2015 2:43 pm    Post subject: Reply with quote

What's wrong with the "orange one"? Moly wouldn't plug it up and reduce oil pressure - it would disintegrate first😄. Clay
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Knarley Darley
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PostPosted: Wed Apr 08, 2015 3:36 pm    Post subject: Reply with quote

af2 nailed it. The filter collapsed internally, in fact when that happens it actually pushes the element into the exit hole even harder as you rev it, and the pressure will go down rather than up with RPM. I also second the orange filters are garbage, in fact no filter would be better if you have a choice.
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William Jones
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Joined: 30 Jan 2006
Posts: 822
Location: Lake city, FL
28514.86 points


1971 Ford Mustang

PostPosted: Wed Apr 08, 2015 8:52 pm    Post subject: Reply with quote

Couple more heat cycles and no problems. He is going to race it in a couple weeks.

Bam

_________________
Take the horse out off the barn and let her RUN BABY RUN!!!!!

92 LX 454ci Clevor 9.24@142.53 N/A
71 Mach1 454ci Clevor 10.16@134 N/A 3850lbs race weight "Lost in fire"
03 Cobra Bone stock 12.42
68 Falcon 363ci 10.55@126 N/A
95 GT 363ci 11.08@118 N/A
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af2
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Joined: 01 Sep 2003
Posts: 5558
Location: grassvalley, ca
71227.76 points


1933 Willys Coupe

PostPosted: Wed Apr 08, 2015 10:23 pm    Post subject: Reply with quote

Knarley Darley wrote:
af2 nailed it. The filter collapsed internally, in fact when that happens it actually pushes the element into the exit hole even harder as you rev it, and the pressure will go down rather than up with RPM. I also second the orange filters are garbage, in fact no filter would be better if you have a choice.



That exactly....
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William Jones
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Joined: 30 Jan 2006
Posts: 822
Location: Lake city, FL
28514.86 points


1971 Ford Mustang

PostPosted: Sat Apr 18, 2015 9:50 am    Post subject: Reply with quote

Well after letting it run a few more heat cycles. I pulled the filter again still had a lot of metal dust and a loose rocker. So I thought maybe got a lifter was able to pull the lifter up to inspect the roller tip and it looked ok. While lifter was out I noticed the cam had moved back in the block and was no longer centered in the lifter bore and had about a 3/8" end play not good. Previous history with this junk when brought it to me the other guy who built never checked PTV and never installed a cam button and the push rods were to short. On the second pass it broke a exhaust valve and destroyed the and a few pistons. While disassembling the engine I discovered it had about .010 clearance on the intake valve I also noted that the cam had to much end play. When I pulled the timing chain I saw why. No button and the Torrington bearing was seized and it had eaten into the block. So we had the block repaired, new heads, new timing chain with out bearing, new pistons, rings and bearings. I wanted the cam replaced because the lobe was no longer flat from the lifter riding on the edge of the lobe. But was over ruled due to cost. I voiced my opinion because I thought it would be an issue. Anyways this thing has ate up the the cam gear not the block I assume because the lobes on the cam are forcing the cam to ride to hard against the front of the block. End play was at .010 when I put it together and we used a cast iron timing set. My plan to correct issue is have cam reground a little smaller to fix the lobes, get new roller lifters, and timing set with bearing, clean the engine up thank god it didn't get into the bearings. I will also dress the repaired cam thrust area on the block. Do you guy's usually drill a small hole in the oil gaily plug to help in oiling the cam gear? This thing is a basket case and if he wasn't a friend who got the shaft I would walk away from it and never have built it to begin with.
_________________
Take the horse out off the barn and let her RUN BABY RUN!!!!!

92 LX 454ci Clevor 9.24@142.53 N/A
71 Mach1 454ci Clevor 10.16@134 N/A 3850lbs race weight "Lost in fire"
03 Cobra Bone stock 12.42
68 Falcon 363ci 10.55@126 N/A
95 GT 363ci 11.08@118 N/A
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Big Dave
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Joined: 04 Dec 2005
Posts: 2646
Location: Tampa Florida
119973.02 points



PostPosted: Sat Apr 18, 2015 1:01 pm    Post subject: Reply with quote

Yes on drilling galley oil plug at a slight angle to aim the oil squirting out at the chain.

Second problem is the stock timing chain cover was not designed for a cam button. There were no roller cams used in a production mark IV block BBC. You need to weld a steel tab on the back side of the cover to spread out the contact force, so it doesn't bend enough to allow the cam to walk.

Only time I use Moly lube is when building with a flat tappet cam. I grease up the lobes and run break in springs (a set of old stock hydraulic lifter springs). Too much grease in the motor will not dissolve in time to prevent clogging the filter. Grease going through the oil pump puts a serious strain on the cam/distributor gear and can literally push the cam hard enough to cause a lifter to hit the edge of an adjoining cam lobe breaking something in the process.

Big Dave
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William Jones
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Joined: 30 Jan 2006
Posts: 822
Location: Lake city, FL
28514.86 points


1971 Ford Mustang

PostPosted: Sat Apr 18, 2015 1:43 pm    Post subject: Reply with quote

Arp bolts require the ARP ultra torque lube which is a molly lube that is what was used on the bolts. The cam is being forced towards the block not the cover and has eaten up the block the first time and the cam gear this time I think it's because of the cam lobe being worn. Which makes the lifters want to ride off the edge of the lobe causing the gear to press up against the block and eventually cause it to wear. I am hoping regrinding the lobe will make the lifter want to stay centered and I will drill one of the galley plugs to oil the timing set. What size hole do you guy's recommend.

Bam

_________________
Take the horse out off the barn and let her RUN BABY RUN!!!!!

92 LX 454ci Clevor 9.24@142.53 N/A
71 Mach1 454ci Clevor 10.16@134 N/A 3850lbs race weight "Lost in fire"
03 Cobra Bone stock 12.42
68 Falcon 363ci 10.55@126 N/A
95 GT 363ci 11.08@118 N/A
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10sec.et
Member


Joined: 29 Mar 2006
Posts: 3473
Location: Houston,Texas
346658.74 points


1969 Oldsmobile Cutlass

PostPosted: Sun Apr 19, 2015 9:51 pm    Post subject: Reply with quote

i believe .040 is what the Olds has. i wouldnt go any bigger.
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af2 wrote:
It seems we can look at our magical Balls and come up with a fix?

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af2
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Joined: 01 Sep 2003
Posts: 5558
Location: grassvalley, ca
71227.76 points


1933 Willys Coupe

PostPosted: Mon Apr 20, 2015 11:09 pm    Post subject: Reply with quote

William Jones wrote:
pistons. While disassembling the engine I discovered it had about .010 clearance on the intake valve I also noted that the cam had to much end play. When I pulled the timing chain I saw why. No button and the Torrington bearing was seized and it had eaten into the block. So we had the block repaired, new heads, new timing chain with out bearing, new pistons, rings and bearings. I wanted the cam replaced because the lobe was no longer flat from the lifter riding on the edge of the lobe. But was over ruled due to cost. I voiced my opinion because I thought it would be an issue. Anyways this thing has ate up the the cam gear not the block I assume because the lobes on the cam are forcing the cam to ride to hard against the front of the block. End play was at .010 when I put it together and we used a cast iron timing set. My plan to correct issue is have cam reground a little smaller to fix the lobes, get new roller lifters, and timing set with bearing, clean the engine up thank god it didn't get into the bearings. I will also dress the repaired cam thrust area on the block. Do you guy's usually drill a small hole in the oil gaily plug to help in oiling the cam gear? This thing is a basket case and if he wasn't a friend who got the shaft I would walk away from it and never have built it to begin with.

Why is the timing chain taking out the thrust?....A roller should have .010? I have .020.... The cam front is the only measurement and should be .010"The running measurement is at the front of the cam because the distributer pushes there on both the BBC and SBC...
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af2
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Joined: 01 Sep 2003
Posts: 5558
Location: grassvalley, ca
71227.76 points


1933 Willys Coupe

PostPosted: Mon Apr 20, 2015 11:11 pm    Post subject: Reply with quote

William Jones wrote:
Arp bolts require the ARP ultra torque lube which is a molly lube that is what was used on the bolts. The cam is being forced towards the block not the cover and has eaten up the block the first time and the cam gear this time I think it's because of the cam lobe being worn. Which makes the lifters want to ride off the edge of the lobe causing the gear to press up against the block and eventually cause it to wear. I am hoping regrinding the lobe will make the lifter want to stay centered and I will drill one of the galley plugs to oil the timing set. What size hole do you guy's recommend.

Bam
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af2
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Joined: 01 Sep 2003
Posts: 5558
Location: grassvalley, ca
71227.76 points


1933 Willys Coupe

PostPosted: Mon Apr 20, 2015 11:14 pm    Post subject: Reply with quote

af2 wrote:
William Jones wrote:
Arp bolts require the ARP ultra torque lube which is a molly lube that is what was used on the bolts. The cam is being forced towards the block not the cover and has eaten up the block the first time and the cam gear this time I think it's because of the cam lobe being worn. Which makes the lifters want to ride off the edge of the lobe causing the gear to press up against the block and eventually cause it to wear. I am hoping regrinding the lobe will make the lifter want to stay centered and I will drill one of the galley plugs to oil the timing set. What size hole do you guy's recommend.

Bam
Sorry Bam
The cam being a solid is the same as any. There is no way a worn cam will cause this unless the roller turned....
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