Engine assembly questions for noobies

I finally had some time to get around to degreeing my cam. So if I did the degreeing correctly I think I'm looking good. I installed the 9 keyway set dot to dot like JW'S thread says to start and my numbers were way out. I retarded the gear by 2 degrees and degreed the cam again (actually twice) and both times the numbers were almost perfect. My 290 94H cam calls for 226 intake 235 exhaust with a 112 LSA or 108 for 4 dgree advance. My degreeing came out to 225.5 intake, 107.75 for LSA and the exhaust came out to only 231, which I thought was weird??. Also as per JW'S degreeing thread if you take my open at 10 degrees plus my close at 8 degrees that's a total of 13 degrees overlap and JW says he doesn't like to see any more than 15 degrees of overlap or it gets dicey for vaccum for power brakes.

 

You had to retard???? I'm not saying its not possible. But just about everytime I've use a 9 way set.....rollmaster.....I've had to be +4 or above just to get cam spec.

 

Here's a pic Ben of where it ended up. I'm still not 100% sure if I did this right or not. Now that I've looked at the degreeing thread again and looked the lower gear I think I actually went 2* advanced?

 

Do it over, keep doing it over till you get a repeatable number and you understand the crank gear markings.
It IS somewhat confusing how the crank gear is marked

 

Hey Mark, that's what I did twice in a row and I got the same numbers. I'm trying to make sense on reading the degree wheel as the way I understand it from JW'S pics you can be read it two ways/directions. My wheel is smaller than the one he uses also so that may play a part it reading it??

 

When I check intake centerline method I always check it at 100 before and 050 before and after max lift........its easy to do and provided an instant double check at a different part of the ramp.....you coul do 150,200 whatever you want..... so I find max lift.....0 my reader back it off 200ish number......bring it back to 100b4, read wheel, then 50b4 and read....go 50 after read, 100 after read. Add the 50s÷2, add the 100s÷2. Compare answers should be close

 

My wheel is small also, actually looks like yours, just pay attention to the numbers on the perimeter of the wheel, I dont think it makes a difference where you have your pointer attached, but I use a water pump bolt hole.
The crank gear markings for 2,4,6,8, A and 2,4,6,8, R and straight up is somewhat confusing until you study it.
Heres a pic of a spare Rollmaster gear and chain assy, for my 350, and the diagram for the crank gear explaining the markings.

 

Inside numbers are where the key goes so the outer number is at the 12:00 o'clock when indexed correctly.

(So key at +2 inner, the outer number will be correct at +2 on the 12/6 o'clock for the gears.)

The pointer does not care, just index the wheel to zero at the pointer when you have piston and lifter at the TDC and bottom of base circle.

FWIW, I use paint to fill the numbers on the gear so I can see them better.

 

What would help us give you confidence that you did it right, would be a picture of the gear set, line up to put the chain on.. so we can verify that the markings on the outer half of the gear, are in the correct position, in relation to where the gear is on the keyway.

In fact, your picture of the lower gear shows that your on the 2A keyway, so the dot on the top gear, must align with the tooth on the bottom gear marked "2A".

Take that picture for us.

Coming up with the same numbers repeatedly, means your doing it correctly. Now lets make sure parts are in the right spot, and if so, your good to go!

JW

 

Thanks for the info and help guys. I'm really trying to get the hang of this as I want to make sure I'm doing it right and going to get the optimal performance from my cam. Jim, here's the pics you asked for. With the #1 piston at TDC and true zero my rollmaster set looks to be what you're describing, the dot on the gear is right above the 2A tooth. I bought this set off another member, it was brand new not used but didn't come with the instructions/guide but someone (maybe TA) engraved the legend on it already. Like I said I degreed it twice in a row after moving the crank gear over and I got the same numbers twice in a row which mostly matches my cam card except the exhaust number came in at 231 instead of the 235 the card calls for?

 

Hey gents any feedback on the above pics I posted on the timing chain and it's current position?

 

Looks to lined up at 2* advanced.

Not to totally confuse you, but I think the factory gear set had 4*advance built in....so its not uncommon to need to be +4 to a true setup ready matching the cam card.......I've had the personally go +6 b4. My cam i just took apart on my blown up 464 was sitting at +8.....I didn't degree it so I dont know if was install advanced or straight up to the card.

But your clearly sitting on the 2*+ keyway and 2*+ tooth is lined up with the cam. So if your numbers match the card your good to go.

 

This motor locked up when last piston was installed, must have been

 

Uh....... Yeah...... every one of those pistons shown is in upside down. Never mind in there twisted due to broken rod

 

Yikes

 

Double Yikes.

Devon

 

So guys update. I've been messing with this engine and trying to degree the cam timing with much frustration. I realized the first time around I was degreeing the intake to the exhaust duration 235 instead of the intake duration 226. So I restarted from scratch, started at dot to dot 0, nope numbers didn't jive. I advanced it 2 degrees and I think I got it this time. So just to make sure I'm doing this right and reading the wheel correctly I took pics of each step. The first 3 pics are the. 050 BTDC readings at 5 degrees and the next 3 pics are the. 050 ABDC readings at 39.5 degrees. Now if I follow JW'S math formula I got 5+39.5+180=224.5 which my cam card calls for 226. So I'm close, I could be off a bit on my readings. Now to see where the cam location is, using JW'S formula I do 224.5÷2=112.25 then subtract the btdc 5 degrees I get 107.25 and my cam card calls for 108. Please see the last picfor my cam card. I hope I got it this time cause if not I'll probably have to send the block back for machining again with all the degreeing miles I've put on this sucker.

 

Your good to go on location. Not at all uncommon for a buick cam to be a couple degrees smaller than the card.. This is because of the small base circle of our cams, in relation the the larger base circle the master is designed for.

Now check the exhaust, this will allow you to not only insure the grind is accurate, but will also allow you to calculate the Lobe Center Separation.

JW

 

Awesome thanks Jim! I didn't want to start doing the exhaust degree until I knew I was doing the intake degreeing properly first. I will tackle that hopefully later today and report back.