your bearings may be bad try switching to a thicker oil and see what happens oil pumps only create flow not pressure bearings create pressure by restricting the flow
Low to No Oil Pressure
- Thread starter WorkInProgress
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WorkInProgress
New member
69.5 Mav and Rbohm,
I am embarrass to say, but I do not know what crank journals are.
I bought some blue Plasti. The results are as follows torqued to 70 foot pounds:
1-.009 inches
2-.006 inches
3-.005 inches
4-.005 inches
5-.005 inches
6-.005 inches
There is some good news, the only place on the crank with scoring is #1. The rest are smooth.
I did not pull the rear main, as I it appears the rear main seal would be compromised by removal of the rear main bearing.
Just as an experiment, I cleaned all of the crud from the mating surfaces of the bearing cap and the corresponding mating surface on the inside of the block on bearing 5. I then turned up the torque to 80 and I got a reading of .004 inches.
So, in theory, if I am trying to hit between .0015 and .003" on the main bearings, I could potentially solve the problem by replacing the bearings with oversize .010 inch bearings on #2 through #6, kinda slow down the oil pressure loss with a oversize .040 bearing on #1 and potentially be in good shape.
Is my theory correct? If so, where do I get oversize bearings? I have found lots of undersize bearings, but no over size bearings.
Are the rod bearing clearances the same as the main bearing clearances?
Thanks again.
James
I am embarrass to say, but I do not know what crank journals are.
I bought some blue Plasti. The results are as follows torqued to 70 foot pounds:
1-.009 inches
2-.006 inches
3-.005 inches
4-.005 inches
5-.005 inches
6-.005 inches
There is some good news, the only place on the crank with scoring is #1. The rest are smooth.
I did not pull the rear main, as I it appears the rear main seal would be compromised by removal of the rear main bearing.
Just as an experiment, I cleaned all of the crud from the mating surfaces of the bearing cap and the corresponding mating surface on the inside of the block on bearing 5. I then turned up the torque to 80 and I got a reading of .004 inches.
So, in theory, if I am trying to hit between .0015 and .003" on the main bearings, I could potentially solve the problem by replacing the bearings with oversize .010 inch bearings on #2 through #6, kinda slow down the oil pressure loss with a oversize .040 bearing on #1 and potentially be in good shape.
Is my theory correct? If so, where do I get oversize bearings? I have found lots of undersize bearings, but no over size bearings.
Are the rod bearing clearances the same as the main bearing clearances?
Thanks again.
James
rbohm":1suph6sa said:
Let me also clarify a bit.
He's got a good top end so I'd hate to break it up if the bearing can be saved.
It don't cost very much to get some new bearings and button it up to see if he can't get some more use out of it.
He didn't actually spin a bearing so the damage might be restoreable.
His perseption of scoring might be exagerated compared to ours.
All in all it should be quick and cheap to get a new set of oversize bearning and try them when compared to what would ammont to a complete rebuild. Once you pull the engine apart enough to regrind the crank you might as well go all the way.
Anyway thats how I see it, start cheap then go for the more expensive repairs if neccesary.
WorkInProgress":1suph6sa said:
A crank Journal is the smooth part of the crank that rotates inside of the bearings. Your crank has 13 journals, 6 rod journals and 7 main journal.
WorkInProgress":1suph6sa said:
70 to 80 foot pounds sounds to high, is this correct?
You have to plasti gage each bearing to be sure. The rod bearing are the ones that take the worst beating so before buy any bearing you need to look at each of them.
WorkInProgress":1suph6sa said:
Are these rod or main bearings?
for number 1 I'd recomend getting .007 oversize and mix and match amoung that set till you get the propper clearance
for the rest I'd recomend .003. You might need a set of .004 for number 2 you'll just have to try plasti gage it to find out.
WorkInProgress":1suph6sa said:
Don't know but I would not count on it.
WorkInProgress":1suph6sa said:
Good Auto parts stores. Tell then you need a bearing to fit an under sized crank journal.
Just for clarification, but does he not need undersized bearings. Because the actually inside measurement of the bearings would be less than what the original bearings were when new to take up the space on the crank which is undersized because its diameter is now less than when it was new.
It's all in what convention you want to use. The bearings must be thicker to take up the space left by an undersized Journal, so the bearings could be thought of as oversized because they are bigger or undersized because their inner diameter is smaller to fit the smaller journal. I've heard both used. What it comes down to is when the rod or main is assembled with plasti gage it must deform the plasti gage to indicate the correct clearence other wise you get to start over.
By the way when you use plati gage the surfaces must be clean and dry, no oil.
By the way when you use plati gage the surfaces must be clean and dry, no oil.
WorkInProgress
New member
69.5Mav,
The 70 Foot Pounds number is from the Classic Inlines site.
My Plasti numbers are from main bearings only, not rod bearings.
I do not know what the rod bearings clearances are supposed to be.
There are no real good auto parts stores in Dallas. We have NAPA, which is pretty good, Autozone, which is not so good. I have called NAPA today, and the largest oversize they can get is .002. It would take a week to get these. Classic Inlines list main bearings for sale from stock to .040, but it does not state if the bearings are oversize or undersize.
Thank you for the education on the journals.
James
The 70 Foot Pounds number is from the Classic Inlines site.
My Plasti numbers are from main bearings only, not rod bearings.
I do not know what the rod bearings clearances are supposed to be.
There are no real good auto parts stores in Dallas. We have NAPA, which is pretty good, Autozone, which is not so good. I have called NAPA today, and the largest oversize they can get is .002. It would take a week to get these. Classic Inlines list main bearings for sale from stock to .040, but it does not state if the bearings are oversize or undersize.
Thank you for the education on the journals.
James
WorkInProgress":1pwluif9 said:
A .002" undersize insert will probably get the #3, #4,#5, and #6 journals within spec considering there is likely some wear on them; #2 might even be ok as well. There is no way that #1 will be acceptable without doing something really phony like shimming (don't even contemplate it)
The only undersize inserts with which I have been familiar come in the .002" size and then .010", .020", .030", etc.
It's time to pull the crank, matey
Joe
I'm just going to throw my 2 cents in here. It has been my experience that every time I try to do a partial repair like some are suggesting, I end up regretting it and spending more money than I would if I just bit the bullet. I've also learned that rebuilding an engine is not a task to be taken lightly. Yes, You can do it. I've rebuilt two engines in my life and one of them actually worked great for years. The other fell apart after 600 miles. More recently, I kept making small repairs and upgrades to the engine in my falcon, not really being satisfied with the resulting performance, and making more small reparis and upgrades, and not being satisfied, and that way spending tons of money and time. In the end I've had to yank the engine and have it rebuild by a competent machine shop. Expensive? Well, it cost a lot of money, but I'm not sure I'd call it expensive. I'm getting a balanced, high compression engine with a hot cam that will make TWICE the power it made stock and be more reliable and smooth than it originally was. And, I've spent more money on half-measures than this rebuild will cost.
So, before you start playing with replacing bearing and whatnot, may I humbly suggest that the precision tolerances that are required to build a quality, durable engine may be harder to achieve than it appears. Yes, you may be able to get all the right sized bearing in all the right places and get years of enjoyment out of this engine. But if you are like many of us and you have the hi-po bug, this may be an opportunity to get that bottom end professionally rebuild by an experienced machinist to your specifications (cam, compression, etc). A process that will provide you with an excellent cornerstone for all future upgrades.
So, before you start playing with replacing bearing and whatnot, may I humbly suggest that the precision tolerances that are required to build a quality, durable engine may be harder to achieve than it appears. Yes, you may be able to get all the right sized bearing in all the right places and get years of enjoyment out of this engine. But if you are like many of us and you have the hi-po bug, this may be an opportunity to get that bottom end professionally rebuild by an experienced machinist to your specifications (cam, compression, etc). A process that will provide you with an excellent cornerstone for all future upgrades.
Most of us have to go to the machine shop to get specialized work done anyways, like decking, boring, etc.
While I agree with FF, I also think that I would like to assemble my next build myself. After all, isn't that the fun stuff? 8)
Since I now have a professionally rebuilt engine I can do the next one without any pressure or deadlines.
While I agree with FF, I also think that I would like to assemble my next build myself. After all, isn't that the fun stuff? 8)
Since I now have a professionally rebuilt engine I can do the next one without any pressure or deadlines.
rbohm":3ibew6su said:
I stand corrected. Thanks.
WorkInProgress":3ibew6su said:
Do the Rod Bearings. They take a lot more abuse and are the ones that will most likely drive you decision to pull the crank.
Lazy JW":3ibew6su said:
From mustangsulimited.com
MS771G1 01 MAIN BEARING SET .01 UNDER 65/75 200 $ 94.95
MS771G2 01 MAIN BEARING SET .02 UNDER 65/75 200 $ 94.95
MS771G3 01 MAIN BEARING SET .03 UNDER 65/75 200 $ 94.95
MS771G4 01 MAIN BEARING SET .04 UNDER 65/75 200 $ 94.95
In 2007 I talked to a tech rep at Clevite and he told me the rod bearings for my sons 302 maverick were available in sizes from STD to .010 in .001 steps and then .020, .030 and .040. I don't know if 200 rod and main bearing are the same but it’s worth a try.
falcon fanatic":3ibew6su said:
It depends on where you catch it. I replace the totally shot rod bearings in my 82 Sentra with 306K Miles and the car runs just fine after 10K (316K Miles) with no rod noise and 27 MPG in the city. My rod journals were visibly and to the touch smooth but the bearing were shot. One was down to the steal and the others were heavily pitted and into the copper.
WorkInProgress
New member
Falcon Fanatic,
Funny how things work, you and I have come to pretty much the same conclusion. I have already thrown a lot of money and time at this thing, and I am pretty much no better off today than I was when I dropped the pan, and I still have to put it all back together. I very well may have gotten away with the thicker oil for 10,000 more miles, which is about 2 years worth of driving for me a weekend/occasional driver car. (I averaged 5,000 miles per year on my 69 Datsun Roadster the last three years, the Mustang is a replacement for the Datsun. I still have the Datsun if anyone is interested.)
I have begun looking around for a used engine. If I could get a decent used engine, I could have it professionally rebuilt with performance parts while driving the car with the cruddy engine. This option buys me time/options and gets the mess in my garage cleaned up. I have found a couple of engines, but nothing really exciting as of yet in the Dallas area. How difficult is it to have an engine shipped?
OK, what am I missing? I am sure there is a downside to what I have outlined that I do not see. What is it?
Thanks again!
James
Funny how things work, you and I have come to pretty much the same conclusion. I have already thrown a lot of money and time at this thing, and I am pretty much no better off today than I was when I dropped the pan, and I still have to put it all back together. I very well may have gotten away with the thicker oil for 10,000 more miles, which is about 2 years worth of driving for me a weekend/occasional driver car. (I averaged 5,000 miles per year on my 69 Datsun Roadster the last three years, the Mustang is a replacement for the Datsun. I still have the Datsun if anyone is interested.)
I have begun looking around for a used engine. If I could get a decent used engine, I could have it professionally rebuilt with performance parts while driving the car with the cruddy engine. This option buys me time/options and gets the mess in my garage cleaned up. I have found a couple of engines, but nothing really exciting as of yet in the Dallas area. How difficult is it to have an engine shipped?
OK, what am I missing? I am sure there is a downside to what I have outlined that I do not see. What is it?
Thanks again!
James
Lazy JW":3oxjwp35 said:
I'm sure they don't. I'm just comparing the cost of a few sets of bearing, some of which you'll end up buying anyway, to the cost of pulling the crank and getting it machined or even worse a complete rebuild.
He has really good compression in this engine and it would be a shame to break it up if it could be saved.
How ever I am a realist and sometime there is nothing for it but to go the whole rout. I would have liked to see him check the rod bearings as they are likely real bad and would necessitate a rebuild.
Balancing the rods will require removing the pistons which means the head will probably have to come off; I see no point in spending money on balancing without doing a full and proper rebuild.
My suggestions about fixing the lower end without opening the top end are intended to help the original poster get his ride running on a low budget for stock performance; any sort of serious performance upgrades truly need to be done with the entire engine in top shape, not just a hillbilly overhaul (for which I am renowned)
Joe
My suggestions about fixing the lower end without opening the top end are intended to help the original poster get his ride running on a low budget for stock performance; any sort of serious performance upgrades truly need to be done with the entire engine in top shape, not just a hillbilly overhaul (for which I am renowned)
Joe
