Engine assembly questions for noobies

Alright so I had a few minutes to mess with the exhaust degreeing, my numbers@ 0.050 are as follows
57 degrees BTDC
1 degree ABDC
57+1+180=238
My cam card calls for 235 degrees on the exhaust, so I'm close. Also I took my intake open at 5 degrees + my exhaust close at 1 degree = 6 degrees of overlap, my cam card calls for 6.5 degrees of overlap.
If I did everything right it looks as if I'm good to leave the cam in at 2 degrees advanced. Are my numbers close enough? Like you mentioned Jim are my numbers out a bit due to smaller base circle?

 

Also I noticed a small amount of scuffing on the cylinder walls in two spots across from eachother. I assume they're from the rings. I did file them to fit and deburred the edges before install. You can't feel them or catch it with your finger nail, is a this normal occurrence?

 

Yes. That is normal. It is not cutting into the hatch, only a bit of burnishing of the "peaks".

If it were ring gap edges, it would be fine scoring, either one or two for each end of the ring(s).

And it is ugly to look at, and you can feel it in your gut.

 

Ok awesome I was really hoping that's what someone was going to say.

 

Just checking in to see if my exhaust degreeing is good and if I'm able to continue with assembly. JW can you chime in with your expertise please sir!
Cheers, Bob

 

Checking the exhaust is a nice double check to make sure it was cut right,

But the only spec on a cam you can change/adjust is the ICL everything else it cut in........so once you have icl......any other measurement are just to verify its cut right and from there its either u run it or you dont.....

Now on a solid lifter cam. The lash adjustment will effect the total duration and lift.......buttons not the cam....thats just the free space that needs to be taken up

 

Thanks for the input Ben. So if I'm understanding you correctly if my cam is in the right location fir ICL as JW mentioned it is then it's good to go? I was under the impression that all my numbers had to match relatively close to the cam card inorder for it to be good to go. That being said my numbers are very close, but could be off a few degrees for the smaller base circle like JW mentioned or human error in the readings.

 

Well got all the slugs in and buttoned up. It feels nice to have this part of the build done and I can really get into the assembly process.

 

All your other number are already ground into the cam.....they can't be changed.

If you adjust ICL it will effect where the opening and closing numbers happen.....so let's say you advance the cam 2 more degrees......now the both intake and exhaust will open and close 2 degrees sooner. The LSA will never change its the space between intake and exhaust lobe centers.....no way for it change.

Sometimes you get the ICL spot on and the opening and closing numbers are off a touch, sometimes you get one event right on and not the others......

Plus your only checking the lobes on 1 cylinde, what if that 1 your checking is the the only 1 cut wonky???? This can be come an endless circle of chasing your tail if you let it.

I check #1.......get it set to my liking.....best average of all the numbers, sports check another random picked hole as verification......and let it go.

 

I follow what you're saying Ben, I read your post a few times and it sunk in on what you were talking about. I figured my numbers are as close as I'm going to get to the card in that 2 degrees advanced position so I decided to let it ride and start putting the thing together.

 

Your numbers look fine Bob, continue on..

Ben, I hear you on checking other lobes, but I can tell you from experience that if you find other lobes that read off, especially as you go toward the rear of the block, then you need to check the camshaft centerline, front and rear, and see if the cam is tipping up or down in the block.. up in the front a little, and down in the rear is what we are seeing, since we started checking them here a couple years ago. We recommend correction for any block with more than a .005 total variation from spec.

Just like anything mass produced, some blocks are very good, others are waayyyy off..

Variations read via cam degreeing, are rarely ever the camshaft.. I don't own the tool, but I know a few guys who do have a cam pro, or similar camshaft checking tool, and most of these guys tell me that the stuff they see from major manufacturers/grinders is usually pretty close. It makes sense that it is, because once the cam is indexed, and the machine set up, it is difficult to screw it up, unless you remove the cam from the machine.

Most grinding errors occur during camshaft indexing.. these errors require the multi keyway chain to account for.. and often are big enough that the whole set has to be advanced or retarded a tooth, advancing/retarding it via the top gear. In other words, you purposely line it up wrong..

I will tell you that one 482 that we fixed the cam tunnel on, and then oversized/corrected the lifter bores to the .875 Ford size, produced some extra ponies that I could not really account for. Also had stellar oil pressure at idle.. something near 50 psi at 700 rpm with 10-30... this is because Buicks are big on the lifter bores.. typically about .0025 to .003 lifter to bore clearance is what I see, even in NOS blocks.. That's twice the ideal number, which is traditionally .0015..

JW

 

That all makes sense.....as the cam tips down it would cause the lifters to riding in a different area ofbthe cam lobe effecting the timing events.

I would imagine the extra clearance in the lifter holes could effect the reading numbers too for them moving around in there too.

 

Sure would help some if the lifters were made at .8425 instead of .8420

 

Excellent, thanks for verifying them for me Jim.