Another 4.6 Build

[4point6]

Well I've been off line for a while with computer problems (HD crash) and other stuff that happens with 3 kids under 5. Anyway, I finally got the block back from the machine shop last Saturday - better late than never. I probably wouldn't have had time to do anything with it anyway. Hopefully will get back active on the forum again now also...

So far I've managed to check main bearing clearances (all between 0.002-0.003), and the check the ring gaps. Then I got to installing the camshaft. I was on the fence between reusing my old cam and the new 89-95 one I got with the rebuild kit. Anyway installed the new one, and it was very hard to turn when the camshaft is all the way in. So I tried the old one - same thing. So my question is: is this typical for new cam bearings to be really tight, or is something f'd up here. I needed to install the timing gear to get enough leverage to turn it, even then it was tough to get it going. Everything was lubed up nice with assembly lube. I forget how it was when I took the old one out (so long ago...).

My thoughts are: 1) this is normal, no problem, 2) one, or more, of the bearings is too small, 3) one of the bearings is installed crooked. Machine shop installed the cam bearings. I measured the camshaft journals for both cams, and they are dead on (2.030" down to 2.000" in 0.010" increments), so its not that... I've never done anything close to this before, so I have no frame of reference. Any thoughts here?

Tomorrow I'll throw the torque wrench on it to see what kind of force it takes to get it going, to quantify things.

Pics, commentary, etc to follow as the build progresses.

[Flash]

Well I've been off line for a while with computer problems (HD crash) and other stuff that happens with 3 kids under 5. Anyway, I finally got the block back from the machine shop last Saturday - better late than never. I probably wouldn't have had time to do anything with it anyway. Hopefully will get back active on the forum again now also...

So far I've managed to check main bearing clearances (all between 0.002-0.003), and the check the ring gaps. Then I got to installing the camshaft. I was on the fence between reusing my old cam and the new 89-95 one I got with the rebuild kit. Anyway installed the new one, and it was very hard to turn when the camshaft is all the way in. So I tried the old one - same thing. So my question is: is this typical for new cam bearings to be really tight, or is something f'd up here. I needed to install the timing gear to get enough leverage to turn it, even then it was tough to get it going. Everything was lubed up nice with assembly lube. I forget how it was when I took the old one out (so long ago...).

My thoughts are: 1) this is normal, no problem, 2) one, or more, of the bearings is too small, 3) one of the bearings is installed crooked. Machine shop installed the cam bearings. I measured the camshaft journals for both cams, and they are dead on (2.030" down to 2.000" in 0.010" increments), so its not that... I've never done anything close to this before, so I have no frame of reference. Any thoughts here?

Tomorrow I'll throw the torque wrench on it to see what kind of force it takes to get it going, to quantify things.

Pics, commentary, etc to follow as the build progresses.

Two questions
1 how much torque does it take to turn the crank with the caps bolted down.
2 how much torque does it take to turn the cam..........

Use a torque wrench and tell me how much it takes.................


Flash

[4point6]

Two questions
1 how much torque does it take to turn the crank with the caps bolted down.
2 how much torque does it take to turn the cam..........

Use a torque wrench and tell me how much it takes.................

Haven't installed the crank yet.

Just checked the cam - about 12-13 ft lbs to get it going. This is torque wrench on the cam timing gear bolt torque. Nothing else in the engine except the cam. Is this normal? Seems like it should turn easier?

[Flash]

Two questions
1 how much torque does it take to turn the crank with the caps bolted down.
2 how much torque does it take to turn the cam..........

Use a torque wrench and tell me how much it takes.................

Haven't installed the crank yet.

Just checked the cam - about 12-13 ft lbs to get it going. This is torque wrench on the cam timing gear bolt torque. Nothing else in the engine except the cam. Is this normal? Seems like it should turn easier?

NO! The cam should flow like butter in there if there is nother but the cam in there.........The crank should be the same way. You should be able to spin it with you and, if it take more effer then that it need to be line bored to fix the problem.

I'm not shore how they fix a cam bore.
with the crank they cut a small amount of the cap and then bore every thing straight again............cam bores don't have caps..

install the crank and see how tight it is.

Then call your machine shop with the details.........they will be able to tell you what to do next

flash

[John]

You should be able to turn the cam by the snout between two fingers, sounds like a bearing issue or core shift from overheating, yes as flash said your machinist needs to see it, setting the crankshaft and bearings into the block to see how it behaves might shed some light also, If it is too tight also, it could indicate general block warping. I hope it is just a bur on one of the cam bearings from a oops during install. Did the shop check centerline of the block to determine if it would need line bored or not?
John

[4point6]

This talk of core shift makes me nervous. I installed the crank and torqued it down - that turns nice and easy. That was good news. So tomorrow I call the shop to see what's up. A quick look at the cam bearings didn't tell much, no apparant dings or anything.

[Flash]

This talk of core shift makes me nervous. I installed the crank and torqued it down - that turns nice and easy. That was good news. So tomorrow I call the shop to see what's up. A quick look at the cam bearings didn't tell much, no apparant dings or anything.

Good news on the crank! does the cam have tight and loose spot,as you turn it or is it tight all the time?

flash

[John]

Excellent, was there any burnished spots or shiny spots visible on any of the cam bearings?
John

[dwg86]

I had the same problem on a 401 I built. When the machine shop installed the bearings, the outer serface of the bearing was peeled bach behind the bearing where the oil hole is in the bearing. This made the bearing egg shaped. The machine shop had to install new bearings. The camshaft turned easily by hand, or should I say fingers, after the problem was corrected.

[John]

I think he is going to find something like that, should show a bright spot where it is tight.
John

[4point6]

I took the block and cam to the machine shop this AM. My guy there took a look, and he wasn't too concerned, he had seen worse. I took a look at the bearings - definately #4 cam bearing was showing some bright spots. My machine shop guy said to shave down the high spots w/ a razor blade, I was a little skepical at first, but it seems to have worked. Got the cam to turn nice and easy like the crank - less than 4 ft lbs. He was thinking the bearings may have been a off spec - now it may have been the #4 cam bearing was installed a little crooked, and I should have had him reinstall it. I'm just happy I didn't just drop $$$ to machine a garbage block that is warped. Tomorrow hopefully get the cam back in for good after a nice cleaning, put the crank back in for good, and maybe even some pistons installed. I think I can see the light...

[John]

Where was the bright spots located on #4?

When the crank came in ok, it was a good sign.
John

[4point6]

Where was the bright spots located on #4?

When the crank came in ok, it was a good sign.
John

There was a spot on the top side about .5 inches long by about 1/8" wide, about .5" from the oil hole. I shaved a bit at a time, reinstalled, rotated, checked for bright spot again, reinstall, etc until no more bright spots. I would have preferred to have reinstalled a new one, but at this point, its done, seems to be fine. Fingers crossed...

[John]

Poor installation by the machinist. You aren't the first to scrape in a bearing, and it will likely be fine. Get a bore brush and clean everything well after scraping. Soap and water works best followed by light oil. If you run into this again, have the shop replace the bearing.
John

[dwg86]

My machinist did the same thing with a pocket knife and said "there ya go". I refused and made them install new bearings. The second set they got right. What a bunch of HACKS!!!!