I would appreciate that -- thanks.

 

Well Friday night I got the timing set put back on and I set it 4* advanced. it started on the first crank set thi ignition timing. let it warm up and then road tested it. Right away I noticed better throttle response. the engine pulls harder to 3000 rpm and feels alot smoother with its power. all in all I am really happy

 

that's the effect

 

That's great. I'm definitely in. Thanks for letting me know how it worked out RustyTub, and thanks for the tip grclark.

 

Hi guys, sorry to jump in but I got a question. I'm fixing to put a comp cams 2121 timing chain in my 400 and the tech at summit said to put it straight up because it already took out the -4 the factory chain had. Would that not give +8 advance?

 

The guy at summit is right, the retard was built in the timming chain, does your new timming chain has the option of advancing and retarding the cam?

 

I know mine does. The gear has 3 notches machined into it labeled: R, 0, A

 

It's always best to degree a cam in if you don't want to just use the 0 slot. Changing cam timing without degreeing in is nothing more than a shot in the dark, Sure sometimes it will run but you have no idea where it's in at and no idea where the cam is ground in at. Too many things working against you. I have a causal friend that put one in at the alleged 4* advance and it wouldn't run right. I ended up taking it back apart. I found after degreeing it in, it was nearly 3* off in the zero slot. So in that instance you can see what problems can arise right out of the gate just putting it in the 4* slot. One other thing, a lot of aftermarket cams already have a 4* advance ground into them.

 

that's why we found the specs to the stock cam and compared them to others.

some applications, by Ford specs, are easily 8* retarded from similar Ford specs of a different model year or application from the cam grind and the timing set(if the application actually did get a retarded timing set, most trucks did not)

and yes, i would advise against 'double stacking' the 4* advance by running a Comp or any other cam with 4* advance already ground in @ the +4* position unless you really took a good look at the specs and decided that's the way you want to run it.

i did an experiment with a AMC 258 in a Javelin. for grins i set the cam timing 1 full tooth on the chain advanced, which came out to 10* the way i figured it(36 teeth on the cam sprocket). admittedly it was too much advance if it were a 'customer car', it ran fine around town and even on the highway but you could tell it was 'out of wind'

in my experience the crank keyway in 335 series engines are pretty darn accurate. some other brand engines it is well known that if you mix years of parts or aftermarket timing covers you could be way off and degreeing / verifying TDC is a must. still not a bad idea with 335's either just to be sure where you're at

 

I must also say that if you are doing a cam change it is always the safest bet to degree in the cam.

For this time I am running the stock cam it is a stock rebuild 400 and I am already building another engine for my truck so I was willing to try the advanced slot and give it a go in hopes for some more power to pull the boat to the lake this summer.

 

Mine is all stock, so i should be good on the 4* advance with little else to do, right? Maybe just throw a timing light on it and make some minor adjustments?

 

Yea I had to adjust the ignition timing. since the Dist is drivin off the cam by advancing the cam 4* you are essentialy advancing the dist about that much

 

ignition advance is not directly related but you may find that it runs better(or not) with a little more base timing or a complete recurve. if you only add more base timing and don't reduce the amount of machanical advance, your total timing will increase by the amount that you add to the base. there's no point in running more timing than you need to make max power, any additional timing will only cause you to need higher octane for no gain

 

I was just saying that when I changed the relationship of the cam and the crank by 4* advance that my base ignition timing had moved forward about 3* and I had to pull it back to where I had it before.

 

That's what I needed to know. Thanks for the info. I just got a 27,000 mile 400 out of a 79 continental for $250 ( everything from the torque converter forward). I'm just gonna change the oil pump and timing chain, and check the bearings.