Timing Chain install 383

roadrunnerh · Sep 4, 2019

Hey folks, once again I need some help. I installed the timing chain Summit https://www.summitracing.com/parts/sum-g6604r-9 with 9 keyways.
I installed crankshaft sprocket at "0". My good buddy told me I should have used the 4 degree advance keyway. Is he right? He claims most Mopar engines should be initially set there.
I'm undecided as to whether I'm going to degree the cam (never did one before).

66Satellite47 · Sep 4, 2019

It depends on what cam you have, duration & recommended installed degree. Advanced cam tends to give a little more low end RPM power & retarded more top end. It is a function of the cam design & cylinder heads. BTW that also affects piston to valve clearance if that is a potential issue.

beanhead · Sep 4, 2019

Degree it! Otherwise roll the bones and set it at zero....and always wonder where it actually ended up. And no most Mopar engines shouldn't just be set there. Where you install it depends on the cam grind and personal preference, more advance moves your power band down, retarding the cam timing moves the power band up, which can be nice in an engine that makes a lot of low-end torque. (I hope your buddy didn't guide too much else on your build

) Degree it and you'll know...

Don Frelier · Sep 4, 2019

The multiple keyways let you fine tune the cam setting and adjust for machining differences in all the parts.
Not too long ago I had a new cam and timing set that was about 5 degrees retarded when installed "straight up".
It's not that difficult to degree the cam with the proper tools, but you need to know what your cam specifications are.
You could split the difference and go for about 2 degrees advance which could help long term when the chain stretches.
To some extent your buddy is correct, in general advancing would be preferable to retarding the cam.

69Bee · Sep 4, 2019

Actually, a lot of cams come ground "advanced". Since people like to advance their cams, the manufacturer took that into account, and ground the advance into it. All that is needed to do is install it straight up. A common number is 4 degrees, although I think one cam was 10 degrees.

451Mopar · Sep 4, 2019

Degree it if you can, otherwise you will never know the true installed position of the cam.
Sometimes when setting the timing at "0", you can be on the mark or close enough. Other times I have had one that was off 15 degrees!
Also, if your a tooth off, or use the wrong symbol for the keyway, you can be way off also.
Anyhow, if you have issues, and don't know where the cam is installed will be asking yourself why you didn't check it when the engine was apart.

As for if the cam should be installed advanced, as mentioned it "depends" on the engine combination.
I think the 4-degree advance may come from people installing slightly larger cams into a stock (low compression) engine, and then they advance the cam to get back some low end power.

vance.dykes · Sep 4, 2019

this is why as others said degree the cam no matter who made it people make mistakes if YOU degree YOUR cam we wont have to help you when you get it running and it doesn't perform the way you want. the cam is the hart and soul of what and how much horsepower you have.

roadrunnerh · Sep 4, 2019

Thanks for the replies guys, I appreciate it!
My friend sounds incorrect as far as a rule. Regardless, it may help to report that this is a 9.2:1 dished pistons, previously a factory 1969 383 2 bbl engine, re-ringed, new cam, rod, and main bearings, Flex honed and thoroughly cleaned. I realize this is not optimal for a rebuild, however, the bores and pistons were pretty good - measured with a Starrett inside micrometer. Forged crank journals all within FSM tolerances. Still I have been told that the engine will not be a true 9.2:1 compression, but probably closer to 8:1 or 8.5:1 as a guess. My goals for this engine are not high. I am replacing a tired 225 in my 1975 Scamp. If it yields 300 hp, I'll be happy (I think).
Here's a breakdown of what I'm using - bear with me.
Comp Cams 21-222-4 cam 262/270 462/470 lift
Cast Iron '68 383 4Bbl intake
Carter AVS factory 383 carb
HP exhaust manifolds
Finally, yes, I have been convinced by you guys to degree the cam. I'll be looking for a degree wheel.

Lefty71 · Sep 4, 2019

roadrunnerh said:
My friend sounds incorrect as far as a rule.

They're like that. Many times there is beer involved. :drinks:

roadrunnerh · Sep 4, 2019

I just got off the phone with Tommy, self described Mopar guy, from Comp Cams tech line. He told me that 4 degrees advance is already built in the
XE-262H camshaft. Also, he said for a street engine, just line up the dots and go, basically. I was a little surprised since I was ready for him to recommend the "Comp Cams degree wheel kit". LOL. I suppose he didn't want to have to explain the process to a first time engine builder such as myself!
I still think I'll degree the cam, with help of course.

vance.dykes · Sep 4, 2019

roadrunnerh said:
Thanks for the replies guys, I appreciate it!
My friend sounds incorrect as far as a rule. Regardless, it may help to report that this is a 9.2:1 dished pistons, previously a factory 1969 383 2 bbl engine, re-ringed, new cam, rod, and main bearings, Flex honed and thoroughly cleaned. I realize this is not optimal for a rebuild, however, the bores and pistons were pretty good - measured with a Starrett inside micrometer. Forged crank journals all within FSM tolerances. Still I have been told that the engine will not be a true 9.2:1 compression, but probably closer to 8:1 or 8.5:1 as a guess. My goals for this engine are not high. I am replacing a tired 225 in my 1975 Scamp. If it yields 300 hp, I'll be happy (I think).
Here's a breakdown of what I'm using - bear with me.
Comp Cams 21-222-4 cam 262/270 462/470 lift
Cast Iron '68 383 4Bbl intake
Carter AVS factory 383 carb
HP exhaust manifolds
Finally, yes, I have been convinced by you guys to degree the cam. I'll be looking for a degree wheel.

get a kit in a case that will have everything you will need in a case that it will be safe clean and ready too use and in an all in place

vance.dykes · Sep 4, 2019

roadrunnerh said:
I just got off the phone with Tommy, self described Mopar guy, from Comp Cams tech line. He told me that 4 degrees advance is already built in the
XE-262H camshaft. Also, he said for a street engine, just line up the dots and go, basically. I was a little surprised since I was ready for him to recommend the "Comp Cams degree wheel kit". LOL. I suppose he didn't want to have to explain the process to a first time engine builder such as myself!
I still think I'll degree the cam, with help of course.

i have bought cam shafts that are supposed to be *** center line and be off DON'T TRUST SALES /TECH GUYS ON THE PHONE center line your cam shaft yourself.

Lefty71 · Sep 4, 2019

With cam degree wheels, as like most things, the bigger the better. :bananadance:

wyrmrider · Sep 4, 2019

good advice here
that cam is IMHO about max for your combination
even the 256 in a lower compression motor
run a compression check and post results
and again if you have to move the cam to get a real 4 degrees advanced
I do not recommend (as many do) extra advance
if you need that you have the wrong cam
advancing also advances the exhaust open which hurts your power expansion cycle and hurts mileage- among other things
In your case comp put the exhaust open where they wanted it for a chevy but should still work better than 440 magnum cam for your combination
get all your tuning and advance curve accomplished B4 making changes
free flowing exhaust? X pipe? cold air? fan clutch? stock rockers?
better combo than most 383 chevies

Timing Chain install 383

roadrunnerh

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66Satellite47

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beanhead

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Don Frelier

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69Bee

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451Mopar

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vance.dykes

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roadrunnerh

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Lefty71

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roadrunnerh

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vance.dykes

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vance.dykes

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Lefty71

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wyrmrider

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