E303 cam advance off?? Any help? thanks

[mancuso4130]

HI,

Well finally got the new motor up to the dyno today and much to my dismay, it wasn't right. Powerband fell off at like 4200. It looked like a bell curve. Tuner thinks my cam advance is off. I set it (E303) advanced at 4 degrees but he said that there is already 4 degrees advance built into that cam. So now we were guessing I was at 8. Has anyone heard of this or any help is appreciated.
I didn't actually degree that cam in, but used New timing chain from summit and lined up my marks perfectly. thanks for the help, mike

 

[MUSTHAVE302]

a lot of cams supposedly have 4* of advance built into them, but installing the cam w/ zero degrees of advance/retard is still considered "straight up". MM&FF printed an article recently where they tested a combo on the dyno with a cam at -4, 0 and +4 degrees. It also was a cam that had 4* advance built in, and suprisingly it made the most power with the cam advanced 4 degrees, for a total of 8* (the same situation you have). The horsepower spread i think was about 15 hp from -4 to +4, and the motor tested appeared to rev just fine, so i doubt that your problem is the advance.

It would be a gigantic PITA to degree your cam now that the car is running. The only thing i can think (cam related) is that the summit chain is a POS and it is off more than 4*. A "poor mans" way to degree your cam would be to buy degree tape that goes around your balancer (i think they have these that are graduated the full 360*), pull the valve cover, and put a dial indicator on the pushrod side of the rocker arm. This will not be as accurate as it would be if the motor was just a shortblock and you had a nice big degree wheel, but it will probably let you know if the cam is way off. You just want to check to see that the cam is opening and closing when it is supposed to. The timing of these events should be on the cam card that came with the cam.

If that's not the problem - obviously something else is causing troubles.

 

[Michael Yount]

I'm with musthave - you're gonna have to measure and see where your cam is actually installed. "Dot to dot" and this amount/that amount of built in advance doesn't really tell you anything. If you want to be certain that the E is installed at 4 degrees advanced, you have to drain the coolant, pull the water pump/fan, pull pass. side valve cover and the 2 rockers for #1, set the dial indicator up, put the degree wheel on, establish tdc with a positive stop in the spark plug hole, and see where .050" lift occurs on the intake valve. If it's not at 4 degrees before TDC (the cam card calls for 0 degrees btdc for the E), and you want it to be, you'll then have to pull the front cover, the gear sets off and reset the cam timing. Once reset - check it to be certain you've got it where you want it - that's what degreeing it entails. With a powerpeak at 4200 I'd say your cam timing is WAY off or the cam is a poor match for the rest of your mods. What's the rest of your set up? Piston to valve interference is another indicator of cam timing being off. If that hasn't been an issue, you may have something else at work too. Good luck with it.

 

[mancuso4130]

Thanks for the info guys. I also just talked to FMS and they told me that the E303 was one of the only performance cams not ground in with the 4* of advance. But I am going to try to degree it after the holidays. It could also be that the summit timing chain is off, I guess. Man, I feel a headache coming on.

 

[thumper460]

advanced... is a term!! ground 4* advanced is also a term.. and it is how the cam is ground!! example if the cam is a 110 center line and and the intake center line is 110 then it IS NOT advanced... but if the cam is GROUND on a 106 centerline, then it is 4* advanced!! that is the tech term. BUT... usually when some one says "I advanced the cam 4*s " that means the cam was advanced 4* past what ever the centerline is cut on ( thus the need to degree the cam to find the true center line on the I/E ) SOOOooo.... the 1st cam cut on a 110 I/C/L if advanced with the timing chain... it is now in at 106*(4* advanced...usually), ORrrr.. if the center line is cut on the 106* (manufacture has 4* cut into the cam) and you use the timing chain to advance the cam then the center line is in at 102* ( right?? 106* - 4* =102*) The freaking terms get lost a lot!! I will advance a cam in from the mfg cut 4*.... Or the cam is mfg with a 4* made into it... is or can be the same center line!!( this example 106*)

The idea is to change the cam phasing for the performance of the engine and to TUNE the cam to your needs!! The closer to TDC, the sooner the intake valve closes and the sooner the engine can build cylinder pressure and the sooner the torque is developed and thus... better bottom end!! SOOOoo.... with the closer center line to TDC on a specific grind, the low end gain and the loss of some top end ( usually the 15-20 ft lbs of torque is offset by the loss of 3-5 hp on the top) is what happens... and when you car looses power at the top end and all the other mods are equal.. your tech made that statement!! " must be advanced" because of the sharp drop in high HP!! Usually it is weak springs, or fuel pressure... IF the cam timing chain was installed "dot to dot" or at the 0 to dot... you are in at mfg ground center line... or for the FMS E cam...110* !!
SOOOooo... have the tech check other paramiters befor you tear the engine down and find out your at the center line * for the E is 110* and you are in at 106* (4* advanced) !! cool??

Just me................................

Thumper

 

[Notchbck93]

Just out of curiosity , what intake set up do you have. My E cam pulls till 5400. and I used the ol' Cloyes Timing chain. FMS same thing. Works great. Straight up install.

 

[Michael Yount]

Thumper said - "IF the cam timing chain was installed "dot to dot" or at the 0 to dot... you are in at mfg ground center line"

That's true if all the components that affect actual cam timing are perfectly manufactured - cam manufacture, timing gears, dot locations on the gears, cam pin placement, pin-hole placement in the cam gear, woodruff key location on the crank, etc. It's rare that all these are perfect. When they're all off a small amount, and off in the same direction (sometimes called tolerance stacking), it's not uncommon that a dot to dot install when checked with dial indicator and degree wheel can be as much as 4 to 6 degrees away from what was intended. I just helped a friend whose custom ground cam was installed dot to dot, and when we checked it, it was 4 degrees advanced from where the custom designer intended it to be installed. We used an indexed timing set to back the cam up (retarded it compared to where it had been installed) 4 degrees so it was opening/closing exactly as the cam card indicated it should.

If you want to be certain that the cam is opening the valves when it's supposed to (what you or the cam designer or the cam manufacturer had in mind, cam card info, etc.) you have to degree it -- there's simply no way around it. Dot to dot simply adds an element of risk to where the actual cam timing is set at. As long as you're willing to take that risk, then installing it dot to dot is fine.

Also, many cams today have assymetrical lobes - that is, the opening rates are different than the closing rates. For that reason, it's pretty good practice not to set the cam timing by the cam centerline method, but rather by the .050" intake opening measurement.

 

[thumper460]

Zackly....!! what Mike said!! To be right , you HAVE to degree the cam and see what the actual c/l is, and is SUSPOSED to be!! cool?? Of all the FMS cams I have degreed , they have been good!! but as Mike said... there are those whose equipment might be just a little off on calibration... and then who knows what your are ACTUALLY getting!!! and just think how much you CAN lose by just a few degrees!! Cool??

Just me..............................

Thumper

Edit... actually wonder how some cars are faster than others, when they are pretty much the same mods and the same cam?? As Mike and I am saying... it is the little things that will win the race.. and knowing the true cam phasing is just one of them!! For the correct power for the engine!! cool

Tpr.

 

[mancuso4130]

Thanks guys,

I think I'm going to pull everything off anyway and check to see where i'm at. I am running the Cobra upper and lower intake for you who asked.
And thumper, I have the performance gt40 springs and fuel pressure set to 42 with 30lb injectors and matching mass air. So your saying to get the 4* advance on this e303 cam at 110* intake and exhaust max lift, would bring it to 106*??? Can you guys explain to me how to degree a cam in, on the car? I am also checking here on the cam card, and it says, all lifts are based on zero lash and theroetical rocker arm ratios. Well, I was told to set rocker arms, Which are also 1.72's, to 1/4 to 3/4's turn past zero lash. Could this have anything to do with problem. Thanks for all the info guys, its great to KNOW.

 

[go-stang5.0]

Something else to look at...what kinda heads do you have? Also, w/ 30's your fuel pressure should be much lower than that with an na setup. 24's should be just fine for you or bump that fuel pressure down. Does the dyno have a wide band? If so hook it up, I almost gurauntee you that your running rich...

 

[undercover50]

Hey the same thing happened to me yesterday. I had my mechanic put in a new E303 cam and timing chain from summit. My mechanic could not get the car to idle right. My power fell off at 3000 rpms. The problem was that summit sent me the wrong timing chain they sent me one for a 1965 mustang instead of one for a 1987-1993 mustang 5.0 . You might want to check your timming chain..

 

[Michael Yount]

mancuso - pm me and we can work our way through how to degree one - just got through helping my buddy degree his FTI combo. Probably easiest to do it on phone rather than email though.

The calibration for the 30's in the maf is based on stock fuel pressures (38-42); if it's calibrated properly, you shouldn't have to mess with pressure. In any event, in closed loop, the computer will adjust bandwidth to increase or decrease fuel in accordance with the O2 sensor data. As a practical matter, small fuel pressure changes get 'undone' by the computer with bandwidth changes - to the extent it's within its range to do so. If the mixture is so off that the computer can't adjust, something beyond fuel pressure is wrong - maf miscalibrated, injector malfunction, etc. I wouldn't mess with fuel pressure just yet; rich or lean will impact peak numbers, but it won't appreciably change the rpm that those peaks occur at unless the combo's running out of fuel (lean) and that's limiting rpm. With 30's (where'd that info come from?) I doubt you're running out of fuel.

 

[thumper460]

under cover 5.0////The cam timing is the same on ALL small block fords.. from the 221 cubes of the 62 era to the 5.0s in the 95's !! The upper timing chain gear was changed in 67 for the better... but the 65 t-c should have worked fine!! Installin at 0 ( or dot to dot ..) is the same!! dont need to answer here... but how much dit it cost you to fix the problem??? Just a thought...

Just me..........................

Thumper

 

[Michael Yount]

Thumper - did you mean to say the cam timing was the same, or the timing chain/gear sets were all the same?

 

[thumper460]

Mike ... damn your fast!! !! the cam timing is to the cam, the gears set are the same with suttle changes to the way they were / are made!! Or a cam with 106 Intake C/L will be a 106 in a 65 289, or a 95 5.0 !! the expression here was the 289 t-chain was causing the cam to fall off on power at 3000 !! and the tech (?) had to go back in and change the set up (?). My point was the cam timing would have been correct, no matter what SBF assy he used, IF it was installed correct form the beginning. Cool???

Just me............... and Merry Christmas you Volvo driving fool!!

Thumper

 

[mancuso4130]

Wow, what an experiene. Well based on what undercover said previously, I was curious to what Summit sold me. I called. They also sent me the SUM G6620 which is for a 65-72 mustang. And would NOT fit my car. It actually even took them awhile to find the one that would. I have an 89 LX, its not rocket science. Well he finally came back with one that would work, believe its the SUM G6651, but i'm over it. I'm going with the FMS one instead. The were actually able to sell them to me at the same price because of their mixup. I bought a degree wheel anyway, just to be sure this time. Once is bad enough, but twice would be unreal. thanks for all the input, I thought for sure, I put it on right. Guess you just never know.

 

[Michael Yount]

mancuso - that's why degreeing it is so important - that way you ALWAYS know. Happy holidays to you to Thumper - you mini-maniac!

 

[blown5.0]

mancuso4130...

you are right to install the e303 with the timing chain set to 4 deg advance. the e303 comes with no adv built in, and it needs it. your timing set should be fine. you could check the cam timing without too much disassembly, remove the pass valve cover, put a dial indicator on it, rotate the motor until the lifter body (not the plunger or rocker) rises .050", then look at the timing marks on the balancer, if they say 4 deg btdc then you are adv 4 deg, it may not be that accurate but will be close. you are also correct about the 1/2 turn to 3/4 turn after zero lash for lifter preload.

personally I think your 30lb injectors at 42 pis is way too much fuel, especially if you have stock heads, or mild heads. the eec when at wot is in open loop and doesnt read the mass air or o2 sensors but gives a pre programmed pulse width, and I garrantee you are seriously rich causing poor power. if you have stock heads then the stock 19lbers at like 45 psi is good. if you have an aftermarket mild heads then 24lbers at like 32 psi is good. but 30lbers at 42 psi is flooding the thing. this I feel is your problem.

 

[mancuso4130]

I figured 30's might be a little high too, but didn't want to change if I go with a supercharger, just get the right FMU and bigger intank fuel pump. On the dyno however, my air/fuel ratio is between 12 and 13 all the way down the power curve. And once I get this cam thing figured out, I am getting custom autologic chip burned.

 

[mancuso4130]

Oh, forgot to mention that I have the gt40X turbo swirl heads and 1.72 roller rockers.