Hot Rod Forum banner
1 - 11 of 11 Posts

·
Registered
Joined
·
14 Posts
Discussion Starter · #1 ·
I replaced a pushrod and started to adjust valve preload on some new roller rockers I ordered. When going through the lash procedure using EOIC I noticed the number 2 exhaust valve was not moving no matter how many times I manually turned the engine over. I decided to take the intake off as I felt something was wrong. Long story but this engine rebuild was a project I was doing with my father. Dad's health hasn't been very good and the engine rebuild has taken over 6 months due to him wanting to be involved but then me finally saying I just needed to get this engine finished. He had ordered all the parts but through the process I think he got mixed up on what year the engine was out of. On top of that the engine is a 1966 396 which has unique issues with oiling the top end and I had to get the groove machined into the camshaft. Dad had also reused some old pushrods that were not for BBC.

Anyway, when I pulled the intake I noticed that the number 2 exhaust lifter was much lower than the others and then when I looked at the cam when turning engine over I saw that the lifters were not centered on the lobs of the camshaft. Also, I am not able to push the number 2 exhaust lifter out as it is stuck at the very bottom (it moves a little but wont come out.) This lifter is sitting much lower then the others.

This is a newly rebuilt engine and hasn't even seen any road time yet.

Below are some pictures I took of the lifter valley where I hope you can see how the lifters are off to the side of the cam. Its like the camshaft may have moved or something after we installed it. I really cant tell if a lob on the cam has been messed up but was thinking I should just pull the camshaft out in order to push the lifter through the inside of the engine and catch it with a piece of PVC pipe.

Any thoughts or suggestions on what I should do or am I overthinking this whole thing.

Thanks again for the feedback and suggestions.

Automotive tire Rim Bicycle part Font Auto part


Automotive tire Bicycle part Rim Motor vehicle Automotive wheel system
 

·
Vendor
Joined
·
28 Posts
Sometimes I've saw a BBC wear the face of the block where the timing gear runs against it. You are most likely going to need to take it completely apart anyway because with that cam lobe being worn off I'm sure its full of metal. I'm sure this isn't what you wanted to hear...but we can help if you need parts to repair it. Good luck
 

·
Race it, Don't rice it!
Joined
·
8,281 Posts
It's trash
Might as well pull it down and start over. Push the lifter out of the bottom or risk scoring the lifter bore.
 

·
Registered
Joined
·
139 Posts
What seems odd to me is why some lifters are close to center and some are way off. Almost like the you have the wrong cam. Top of the second picture the lifter is hitting the lob next to it on the edge. Something is seriously wrong.

Sorry to see this.
 

·
More for Less Racer
Joined
·
20,462 Posts
Flat tappet lifters should be slightly off center with the lobes....this is part of the designed criteria to help rotate the lifters during operation.....but they should all be offset the same amount and in the same direction on the shaft.

What you've got going on is hard to say at this point because it appears cam lobe offset is wildly innacurate, but it is trashed at this time and needs to all come back apart for cleaning, inspection as to what is wrong, and correction with new parts.

At first I thought maybe cam retainer plate left out, but that would make all lobes way off in just one direction.....it looks like maybe an incorrect cam blank was used if that is even possible for the cam company to even do that, if there is another brand like BBMopar or something that is close enough to get mixed up at the manufacturing level.

Do you have any idea of the cam and lifter brand??

You are correct, pull the cam and push the lifter out the bottom of the bore....if you try to force it out the top it will tear up the lifter bore surface.

Can you describe the cam break-in process you used??
 

·
Registered
Joined
·
146 Posts
look at the lifter base chip on the cam lobe in his pic. some lifter are offset on the lobe. in my pic to help lifters spin around when motor is running. Maybe cam lube / not enough ZDDP-zinc in break oil, was the motor prime very good from the oil pump.
 

Attachments

·
Registered
Joined
·
14 Posts
Discussion Starter · #8 · (Edited)
Flat tappet lifters should be slightly off center with the lobes....this is part of the designed criteria to help rotate the lifters during operation.....but they should all be offset the same amount and in the same direction on the shaft.

What you've got going on is hard to say at this point because it appears cam lobe offset is wildly innacurate, but it is trashed at this time and needs to all come back apart for cleaning, inspection as to what is wrong, and correction with new parts.

At first I thought maybe cam retainer plate left out, but that would make all lobes way off in just one direction.....it looks like maybe an incorrect cam blank was used if that is even possible for the cam company to even do that, if there is another brand like BBMopar or something that is close enough to get mixed up at the manufacturing level.

Do you have any idea of the cam and lifter brand??

You are correct, pull the cam and push the lifter out the bottom of the bore....if you try to force it out the top it will tear up the lifter bore surface.

Can you describe the cam break-in process you used??
Thanks for the feedback. My father purchased the master rebuild as part of a kit from Clegg Engine. Here is a screenshot of the parts in the kit:

Font Number Terrestrial plant Document Circle


I Googled the camshaft and it appears to be an Engine Pro Performance Camshaft maybe this one: https://sandiegoengineparts.com/products/engine-pro-performance-camshafts-mc1737-1

I was able to get the lifters out by pushing them through the engine and collecting them in a cut piece of pvc pipe. 7 of them were stuck and were mushroomed pretty bad. The cam looks like it has multiple lobes wiped.

The break in process was a tough one. As mentioned this build was done as a father son project where my father's health made the build go much longer than I was wanting and that worried me with the engine being open and exposed longer than it should imo. We always had issues with oil getting to the top end and after several attempts of priming the engine for as long as 30 minutes with not much oil getting to top end, my dad wanted to just fire it up and he felt the oil would get there with higher rpms. Through research I found out that the 1966 396 block we have requires a special grove cut into the rear of the camshaft, this only was for 1965-66 blocks from what I have learned. We were also using a 30+ year old carburetor at first to try and get the engine started and were having lots of issues. I was telling my father shouldn't we at least have the carb rebuilt or something. I went ahead and purchased a new Edelbrock carb and the engine fired up immediately without issues.

I even had a neighbor of my parent who used to own a auto shop bring his mechanic over to look at it and he never was concerned with the lack of oil to the top end, but I always did. I was only able to get the first part of the break in done where I ran the engine at 2000 rpms for 10 minutes and then the radiator threw up because it overheated. The mechanic guy came over the following weekend and ran the engine at idle for 20-30 minutes to try and get the air out of the coolant system he said. I told him that the cam needed to be broken in and that this worried me.

During this time I had a bent push rod, I think because partially my father bought used push rods that were not the heavy duty size for big blocks. I replaced them all with 3/8 push rods from Comp Cams along with guide plates.

This Wednesday I received new roller rockers to replace the used Crane rockers my dad purchased off of Facebook. I finger tightened the rockers on and went to prime the engine and oil immediately was flowing out like crazy. I was super happy as this is the first time in a month that it looked good. I then went to set lifter preload and noticed several valve springs were not moving. That's when I pulled everything off and saw the issue with the camshaft.

We used Royal Purple Engine Break-In Oil https://www.royalpurple.com/product/engine-break-in-oil/

I am now in the process of pulling the engine so I can see how it looks inside the oil pan and if I can clean everything myself or if it has to go back to a machine shop. I am hoping I can do it myself.

I am also seriously considering going with roller lifters and cam this time as I understand they dont require a break in like flat tappets do.

Would not doing the camshaft break-in process almost immediately upon getting the engine fired up cause this kind of cam and lifter failure? I was also reading another forum where they mentioned if springs were too tight this could cause it. The machine shop did the valves and springs btw.

Appreciate all the feedback because this rebuild has been a nightmare but I am not going to give up. Wanting to get this engine finished so my father can be proud :).

Thanks,
Jason
 

·
Rod...from a Chrysler?
Joined
·
5,654 Posts
That's too bad.
I will never use a flat tappet cam again.
 

·
Race it, Don't rice it!
Joined
·
8,281 Posts
Nothing wrong with FT cams. Although they generally require more set up. It's hard to argue with the millions of them still on the road.
 
1 - 11 of 11 Posts
Top