Cam degreeing

Moderator: Moderators

User avatar
Mick70RR
Posts: 1885
Joined: Sat Apr 02, 05 8:57 pm
Location: Birmingham

Cam degreeing

Post by Mick70RR »

Anyone degreed a cam with the engine in the car? What size degree wheel will clear the crossmember?

I fitted a new cam a few months ago without degreeing it. It's the Mopar 528 solid and I had assumed the cam was ground straight up, so I installed it 2* advanced using a 9 way timing set. I did a bit of searching and couldn't find anything that said advance was ground in or not. Decided to check it today using the valve lash method, check the bottom of this page.

http://www.iskycams.com/degreeing.php

I was surprised how conclusive this was. Verified TDC on the damper first using a piston stop and had to adjust the pointer on the timing cover about one degree. Luckily it's a bolt on pointer so I could move it a bit.
Checked the cam at TDC and the intake lash was a lot more than the exhaust lash so it was advanced. Did it all again, this time using 4* BTDC and still advanced. Again at 6* BTDC and this time retarded. Finally one more time at 5* BTDC and the cam was straight up, same lash on the intake and exhaust give or take a few thou.

The LSA is 112* so the cam is installed at 107*.
Looks like they do grind a few degrees into the cam. Runs fine on the street so I'll leave it there for now but may retard it later. It just looks like a pig of a job with the engine in the car.
1970 Road Runner, 505CI, 4 speed, GV overdrive, 3.91 gears.
11.98 @ 117mph on street tyres
Anonymous

Post by Anonymous »

deleted
Last edited by Anonymous on Sun Feb 20, 11 4:19 pm, edited 1 time in total.
User avatar
Mick70RR
Posts: 1885
Joined: Sat Apr 02, 05 8:57 pm
Location: Birmingham

Post by Mick70RR »

It's more accurate than you think, I was surprised. This is a single pattern cam with symmetrical lobes so how can it be innaccurate.
What size degree wheel do you use when the engine is in the car?
1970 Road Runner, 505CI, 4 speed, GV overdrive, 3.91 gears.
11.98 @ 117mph on street tyres
Anonymous

Post by Anonymous »

deleted
Last edited by Anonymous on Sun Feb 20, 11 4:20 pm, edited 1 time in total.
Anonymous

Post by Anonymous »

deleted
Last edited by Anonymous on Sun Feb 20, 11 4:20 pm, edited 2 times in total.
User avatar
Mick70RR
Posts: 1885
Joined: Sat Apr 02, 05 8:57 pm
Location: Birmingham

Post by Mick70RR »

Well if it's good enough for Isky it's good enough for me. Question is, what size degree wheel clears the crossmember?
1970 Road Runner, 505CI, 4 speed, GV overdrive, 3.91 gears.
11.98 @ 117mph on street tyres
Anonymous

Post by Anonymous »

deleted
Last edited by Anonymous on Sun Feb 20, 11 4:21 pm, edited 1 time in total.
User avatar
Dave-R
Posts: 24752
Joined: Sun Apr 18, 04 11:23 pm
Location: Dave Robson lives in Geordieland
Contact:

Post by Dave-R »

Most cams these days have +3 degrees built into them when straight on the timing gear marks. As long as the timing gear marks are correct.

I have only degreed two cams in my life to be honest. The last two of the three I have had in my 440 Chally. I found both to be correct with the marks on my good quality but affordable Australian made timing gears.
But to be sure I measured all the timing events for the intake and exhaust on one cylinder. Both opening and closing.

It was a lot of work setting the dial gauge up to read correctly just to find the timing was correct as installed anyway. So I felt a bit of a fanny.
But if I had been a REAL fanny I would have checked EVERY cylinder in case of manufacturing errors. I couldn't be arsed with that palaver though. :lol:
User avatar
dustymopar
Posts: 1448
Joined: Tue Aug 01, 06 6:39 pm
Location: Chelmsford

Post by dustymopar »

Mick70RR wrote:Question is, what size degree wheel clears the crossmember
I've used a 11" wheel with the motor in situ (Morosso & Mr G).

Adam, I'm interested on your view upon the best cam degreeing method. Would that be the 'Centre-line' method that I have used or another?
Enough is never ever enough....
Anonymous

Post by Anonymous »

deleted
Last edited by Anonymous on Sun Feb 20, 11 4:19 pm, edited 1 time in total.
User avatar
Mick70RR
Posts: 1885
Joined: Sat Apr 02, 05 8:57 pm
Location: Birmingham

Post by Mick70RR »

dustymopar wrote:
Mick70RR wrote:Question is, what size degree wheel clears the crossmember
I've used a 11" wheel with the motor in situ (Morosso & Mr G).
Cheers, a mate of mine has a Mr Gasket degree wheel so it looks like it will fit.
1970 Road Runner, 505CI, 4 speed, GV overdrive, 3.91 gears.
11.98 @ 117mph on street tyres
User avatar
Mick70RR
Posts: 1885
Joined: Sat Apr 02, 05 8:57 pm
Location: Birmingham

Post by Mick70RR »

Dave wrote: But if I had been a REAL fanny I would have checked EVERY cylinder in case of manufacturing errors. I couldn't be arsed with that palaver though. :lol:
Good point Dave, you have to have some faith that these days a cam grinder can get it within a degree. How many people do check the timing events on more than one cylinder, very few I bet.
1970 Road Runner, 505CI, 4 speed, GV overdrive, 3.91 gears.
11.98 @ 117mph on street tyres
Anonymous

Re: Cam degreeing

Post by Anonymous »

deleted
User avatar
dustymopar
Posts: 1448
Joined: Tue Aug 01, 06 6:39 pm
Location: Chelmsford

Post by dustymopar »

Adam, I had read what you had written - thanks :thumbright:
Enough is never ever enough....
Anonymous

Post by Anonymous »

dustymopar wrote:Adam, I had read what you had written - thanks :thumbright:
No probs Dusty , will be moving on.

:thumbright:
Post Reply