454 Engine remanufactured Jasper engine low oil pressure

[ARCOgraphite]

Thank you so much. You've really helped me understand. Have a previous shop owner coming over tomorrow and we can discuss your info. Thanks for taking the time to give me the information.

I mentioned most of this in post #30. If you have cold reading of 60psi then you likely do not have a relief valve issue. You did not mention if this was at idle. If its at high rpm there could still be an issue.

Big blocks can have drain back issue and crankcase venting issues- but more in aluminum race blocks without cross drilled main feed and grooved bearing you would have oiling issues - not oil pump related pressure issues per se. The valley drain back holes are small and the oil hit the cam on the way back to the pan where the oil spray and crankcase ventilation can further impede drain back- again more in race blocks /cold oil.

What is the fully warned up oil pressure gauge reading at each rpm step from 1000- 4000 rpm?

Also, is the engine noisy or quite when fully warmed?

- Ken

 

[Chris142]

I have a feeling Jasper and Cardone hire off the street for minimum wage and have little or no training. Not an engine builder - even I know critical clearances must be checked. But it takes time, tools(Plastigage, dial gauges) and training(how to read a dial indicator or Plastigage) to do that.

Those workers at Jasper and Cardone from what I’ve read here simply clean, assemble from “good” parts, paint, package and call it a day.

In the 90's I worked at a kragen Auto store. They sold engines rebuilt by a company called Bonded.

These were downright terrible! Guaranteed to make a customer mad.

I ordered a guy a 300 ford 6 cyl short block.when it came we checked it out and every cyl was a different bore size!

A couple were standard and you could see where they had removed the ridge and honed over the roughness. They had also sanded the original pistons to clean them.

Another bore was .040 and a couple others were .060.

 

[RAB TX]

The bottom line is you bought a long block and they should either repair or replace it regardless if its oil pump or bad bearing clearances.
20 psi@3000 is not good by any ones standard. IMO it does no good guessing what the cause is, there could be so many from a weak pump/relief valve, a loose oil pump or gasket not seated properly, loose/leaking galley plugs, loose cam/crank/rod bearings to a engine that should have been line bored that instead had mismatched bearings installed to compensate for a tight crank (which doesnt work btw). Over the years I have seen all of these and more.

Thank you for the insight into the wide range of issues that could possibly be the cause. Pulling and installing in a Class A MH is not as simple as in a car. But you're experience has much validity and can't be ignored.

 

[RAB TX]

I mentioned most of this in post #30. If you have cold reading of 60psi then you likely do not have a relief valve issue. You did not mention if this was at idle. If its at high rpm there could still be an issue.

Big blocks can have drain back issue and crankcase venting issues- but more in aluminum race blocks without cross drilled main feed and grooved bearing you would have oiling issues - not oil pump related pressure issues per se. The valley drain back holes are small and the oil hit the cam on the way back to the pan where the oil spray and crankcase ventilation can further impede drain back- again more in race blocks /cold oil.

What is the fully warned up oil pressure gauge reading at each rpm step from 1000- 4000 rpm?

Also, is the engine noisy or quite when fully warmed?

- Ken

This engine, when at operating temp, sounds the same as the original in its prime at RPMs between 2K and 4K. When at operating temp, the oil pressure at idle (600 RPM) is about 8#, 2K is 20#, at 3K is maybe 22# and I haven't stretched it to 4K. On an 8% grade for about 10 minutes, the pressure was falling and temp raised. I wasn't watching that closely because I was just hoping it would get to the peak without failing completely.

 

[ARCOgraphite]

This engine, when at operating temp, sounds the same as the original in its prime at RPMs between 2K and 4K. When at operating temp, the oil pressure at idle (600 RPM) is about 8#, 2K is 20#, at 3K is maybe 22# and I haven't stretched it to 4K. On an 8% grade for about 10 minutes, the pressure was falling and temp raised. I wasn't watching that closely because I was just hoping it would get to the peak without failing completely.

Wow.

 

[Chris142]

This engine, when at operating temp, sounds the same as the original in its prime at RPMs between 2K and 4K. When at operating temp, the oil pressure at idle (600 RPM) is about 8#, 2K is 20#, at 3K is maybe 22# and I haven't stretched it to 4K. On an 8% grade for about 10 minutes, the pressure was falling and temp raised. I wasn't watching that closely because I was just hoping it would get to the peak without failing completely.

If you don't have any luck with getting it fixed you may need to drive it till it blows.

 

[wtd]

Hi clinebarger,
The workhorse chassis from National came with a 454 7.4 L engine. I don't know what a "454 HO" is. Jasper shipped a complete 454 engine, not a short block. The installation shop reused the injectors from the original engine. There is no crate engine involved; so, I don't think a L29, whatever that is, is going to be involved as well as the timing cover, crank sensor, or reluctor wheel since the engine runs and has about 1200 miles on the Jasper engine.
RAB TX

The L29 if I remember correctly is the 454 Vortec engine made from 96 on. My 1998 K3500 Chevy truck has the L29 454 in it. It specs 5W-30 and it runs around 22-25 psi on the factory gauge at a hot idle in gear which right now is not working correctly since it bounces around.

 

[SwampSurvivor]

+1

Jasper has never been known for quality, but have been the go-to for many shops because of pricing. I remember a lot of issues in the Jeep community with their rebuilt 4.0 engines. They would come with all different sized bearings, clearly worn pistons, scored cam bearings, etc. It was like they took their cores and just spray painted them, put them on a different pallet, and shipped them out. Embarrassing.

The ol craigslist rebuild!

 

[SwampSurvivor]

In the 90's I worked at a kragen Auto store. They sold engines rebuilt by a company called Bonded.

These were downright terrible! Guaranteed to make a customer mad.

I ordered a guy a 300 ford 6 cyl short block.when it came we checked it out and every cyl was a different bore size!

A couple were standard and you could see where they had removed the ridge and honed over the roughness. They had also sanded the original pistons to clean them.

Another bore was .040 and a couple others were .060.

Most of the later Jeep 4.0s had multiple bore sizes due to worn out casting equipment. That's why they all have "lifter tick" ... which is really piston slap

 

[Chris142]

Most of the later Jeep 4.0s had multiple bore sizes due to worn out casting equipment. That's why they all have "lifter tick" ... which is really piston slap

My 2002 does not tick

 

[jerryg]

With all comments and fixes, if Jasper will not fix or replace. Install a high volume oil pump add extra quart of oil and drive.

 

[RAB TX]

With all comments and fixes, if Jasper will not fix or replace. Install a high volume oil pump add extra quart of oil and drive.

Thanks Jerryg,
I'm going to start first with replacing the oil pressure relief valves. After that, if necessary, it'll be the oil pump. Didn't know about the high volume one.

 

[ARCOgraphite]

Use a std pump. But a working one without a leaky pickup tube.
HV pumps use a lot of HP are not necessary on street or med duty truck engines.
remember the cam gear drives the oil pump through a wimpy shaft.
if bearings are wide due to a sloppy rebuild, only increasing oil viscosity will crutch that.

 

[wpod]

Back in my hot rods days we all had Big block Chevrolet engines. They were very simple engines. If the machine work was spot on you could put one together in your sleep and have it last and last. Jasper seems to have their problems.

 

[PontiacHO]

In the 80's I worked as an engine builder in a marina with a big on premises machine shop. We built countless big and small block chevys.
The ones that didn't go on the dyno at least got ran on the test stand. We checked oil pressure, temp, timing... Always made sure they were good so we didn't have a surprise after it went in the boat.
It was normal for a fresh engine to have 20 psi at hot idle but they were always better than 10 psi per 1000 rpm.

This above is correct. My guess is the crankshaft has been turned down with different clearances on the journals and mains. Typically cheap low quality rebuilder tricks. If half the rod journals can be polished instead of matching then that’s all it gets. (Same scenario when buying a “remanufactured” crank) Then mismatched undersized bearings throughout. The minimum wage employee slamming it together doesn’t care and mismatches the bearing shells. It’s a common issue…..

 

[RAB TX]

Use a std pump. But a working one without a leaky pickup tube.
HV pumps use a lot of HP are not necessary on street or med duty truck engines.
remember the cam gear drives the oil pump through a wimpy shaft.
if bearings are wide due to a sloppy rebuild, only increasing oil viscosity will crutch that.

Thanks ARCOgraphite,
There's so much info coming in. I'm not aware of most of it, but since I'm going to have to let a shop make it right, I'm not sure I'm going to be able to convince them to take it all into consideration.

 

[RAB TX]

This above is correct. My guess is the crankshaft has been turned down with different clearances on the journals and mains. Typically cheap low quality rebuilder tricks. If half the rod journals can be polished instead of matching then that’s all it gets. (Same scenario when buying a “remanufactured” crank) Then mismatched undersized bearings throughout. The minimum wage employee slamming it together doesn’t care and mismatches the bearing shells. It’s a common issue…..

Thanks to both of you for the additional possibilities of what could have gone wrong.

 

[Chris142]

This above is correct. My guess is the crankshaft has been turned down with different clearances on the journals and mains. Typically cheap low quality rebuilder tricks. If half the rod journals can be polished instead of matching then that’s all it gets. (Same scenario when buying a “remanufactured” crank) Then mismatched undersized bearings throughout. The minimum wage employee slamming it together doesn’t care and mismatches the bearing shells. It’s a common issue…..

Don't most rebuliders grind all the journals the same size? They do here.. usually.10 on the mains and .10 on the rods etc

 

[RAB TX]

Don't lost rebuliders grind all the journals the same size? They do here.. usually.10 on the mains and .10 on the rods etc

Chris142,
Your mention of .10 is the same number that Jasper gave me when I called to question the low oil pressure. What I didn't understand is whether or not they used .10 undersized bearings. Is that a requirement when ground by .10? Thanks if you can answer that

 

[Chris142]

Chris142,
Your mention of .10 is the same number that Jasper gave me when I called to question the low oil pressure. What I didn't understand is whether or not they used .10 undersized bearings. Is that a requirement when ground by .10? Thanks if you can answer that

Yes. If they put standard bearings on a .10 crank it would have already blown up