Im putting a new timing chain on my 93LX along with a set of Thumper heads,would I see much of a performance difference if I advanced the stock cam?? Thanks in advance!
Advancing stock cam
- Thread starter willys1
- Start date
Vipersix
Founding Member
Heh... thanks in advance... no pun intended right?
No matter what cam you have in there, once you start playing with timing you WILL see performance changes. They may be for better or for worse but you'll get some sort of change.
Advancing the cam timing generally improves mid-rpm power and response while retarding the cam improves high-rpm breathing and power. This is a generality however so don't assume you will make more power on your particular combo. Experimentation is sometimes the only determining factor.
No matter what cam you have in there, once you start playing with timing you WILL see performance changes. They may be for better or for worse but you'll get some sort of change.
Advancing the cam timing generally improves mid-rpm power and response while retarding the cam improves high-rpm breathing and power. This is a generality however so don't assume you will make more power on your particular combo. Experimentation is sometimes the only determining factor.
Vipersix
Founding Member
I think about everyone has played with timing at a time or two in their career. I advanced my old engine to the point where it would be pinging on 93 octane if I advanced any more. I was happy with the results.
Vipersix, he is talking about cam-to-piston timing (or mechanical timing), not ignition (spark advance) timing.
Willys, I am not sure what to tell you. I would probably degree it and stick it in straight up, but it would be because I dont know specs, etc on it. Have you tried asking Mike? One would think he has some sweet suggestions for his 'own' parts.
Good luck.
Willys, I am not sure what to tell you. I would probably degree it and stick it in straight up, but it would be because I dont know specs, etc on it. Have you tried asking Mike? One would think he has some sweet suggestions for his 'own' parts.
Good luck.
Vipersix
Founding Member
Yeah I know... my first thread refered to the mechanical advance/retard. Guess I could have left out that second one though since it was simply rotating the distributor and that's not what was being asked about.
So you did. My bad. I saw a couple references to what seemed like ignition timing and thought you had misread the initial post.Vipersix said:Yeah I know... my first thread refered to the mechanical advance/retard. Guess I could have left out that second one though since it was simply rotating the distributor and that's not what was being asked about.
The ONLY reason I advanced my cam is because I took off the valve events and got professional help from Buddy Rawls in determining the best way to install the cam - 109ICL.
I changed intakes too, but the cam made more power and peak was really pretty flat from 4,500-5,500 rpm where we stopped the pull. I just got my engine back together today afdter needing to replace a FRPP lifter tha went bad after replacing my 1.6 Scorpions with 1.7 rockers. They had less than 2,000 miles on them and one just had the valving fail and went "soft" making all kinds of noise.
I changed intakes too, but the cam made more power and peak was really pretty flat from 4,500-5,500 rpm where we stopped the pull. I just got my engine back together today afdter needing to replace a FRPP lifter tha went bad after replacing my 1.6 Scorpions with 1.7 rockers. They had less than 2,000 miles on them and one just had the valving fail and went "soft" making all kinds of noise.
Ranchero5.0
The Voice of Reason
I always put them at least the first setting advanced just to make up for chain slop. Willy before it's too late check the chain slop by fitting the balancer and a pointer up to the timing marks and rotate the crank back and forth to see how much slop there is, then divide that number in half and that's the minumum you should advance it if you have a $70 or up timing chain. Cheaper chains need a lot more advance. I've seen an Auto Zone $35 chain stretch 15 degrees total in ten thousand miles. Kept wondering why the timing kept retarding...
My used FRPP had 4 degree slop so I went 2 degrees advanced to keep it honest.
Jamie
My used FRPP had 4 degree slop so I went 2 degrees advanced to keep it honest.
Jamie
jwzg
Member
Not to hijack the thread, but Tom, I just replaced my rockers with 1.7's and I'm getting a pretty hard tapping noise at around 2000 rpm as well as a vibration. Sounds like it's coming from the #3 or #4 cyl. What did your's sound like? Can you send me a PM?
jwzg said:
Mine was a loud tappet sound - I used a automotive stethescope to ID which valves were the loudest and readjusted the lifters a couple of times. I still had one very loud lifter. It would clatter when first started until oil pressure rose, then it would shut up until the oil got hot and then it would clatter again. I just replaced it this weekend and now the valve train is much quieter - I still have one or two that need small adjustment on the other bank. The valving in this lifter just went bad. I could use the force of my hand on the rocker to compress that one lifter where I could not on the others which would remain "pumped up" with pressure.
Hey Tom I sent you an e-mail.Do you know if Thumper mills his heads? Gotta find out if I need shims or not.
jwzg
Member
Tanks Thom. My intake is bad on the #4 cyl. and I can depress it by hand as well. It's not as loud as yours, but I'm pretty sure the valve is not completely opening. Have to replace it when I return home in two weeks.
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