?'s about retarding cam

[Grn92LX]

Ok, I had my car dynoed yesterday and tuned w/ an autologic chip. Combo is in sig and heads are milled .020" and I run 30lb injectors with a pro m 80mm maf (calibrated for 24's but chip fixes that) My car made 302rwhp/329tq. Car is only peaking at 5300-5400. Low end tq is nice, starts maming 300ft'lbs by 2900-3k rpm. Now that is low for my combo. I expected more from it. I am planning on retarding my car. My ? is, should I retard it 2 or 4*? I emailed Ed C but no responce yet. How much does a 2 and 4* retard extent the powerband? How much could I gain my retarding it to 2 or 4*? Also, to retard it, im just going to use the timing chain I dont have access to the degree wheel tools and I AM NOT buying them. Do I just remove the chain, turn the cam gear to 2 or 4* then put it all back? Next time I hit the track im also gonna try advancing the timing 2* as maybe they didnt tune in enough timing, they were shocked when I told them I ran 18* initial, but I know that was best as dyno AND track told me so.

Thanks,

Mike

 

[Grn92LX]

buMp

 

[Michael Yount]

You won't like my answer Mike - but unless/until you degree the cam, you won't really know what the cam timing is. It could very well already be retarded 2 to 4 degrees from where Ed wanted it installed, which would mean that moving it another 4 might be WAY too much. If you get a hold of Ed one of the first questions he's gonna ask is where is the cam installed? And "dot to dot" doesn't tell him anything. You can buy the stuff you need to degree it for less than $50 - can't understand why you'd spend the money you did on a quality combo, and then guess at where the cam timing is. But that's just me.

Also, there's no guarantee that retarding it (assuming it's installed where it should be) is going to shift the power band up. That's a general rule of thumb - but it's not always the case for every cam/combo. If I were in your shoes I'd definitely talk to Ed first. I'm guessing the cam timing he recommended is optimal - but his model can probably tell you what will happen if you start moving it around. But - you have to degree it to know where it's set -- there's no way around it. Just going dot to dot or selecting a particular key-way on the index gear doesn't tell you where the cam timing is actually at. You'll just know which way you moved it. By the way, he's also probably gonna want to know what your cranking compression numbers are - that'll also tell you something about cam timing, and the condition of the bottom end. It's not uncommon when folks are unhappy with the output of a combo that ring seal is compromising cylinder pressure. Did you rebuild the bottom end when you bolted on the top end stuff? Good luck with it.

 

[Jkstang78]

Hey Mike maybe there is something in here that will help you. I just rembered that I hadd saved this.

http://www.newcovenant.com/speedcrafter/Engine/Cam/default.asp

 

[Michael Yount]

Jkstang - great link; I'll save that one for reference by others. Mike - see lesson #3 - read the last sentence in it. Talk to Ed before you start trying to mess with the cam timing.

 

[Grn92LX]

Hmm, that link says that retarding it 4* will move powerband upward 200rpm. That seems low. I do not plan on degreeing the cam, I dont have the money for the tools and i am not paying anyone to do it. In an email from Ed a while ago, he told me to degree it to be sure, but installing it at 0 should be 106* centerline and I should try retarding it 2* on the timing chain for 108* centerline.

Im just kinda not happy with all of the changes I made to the combo, I am not seeing much better numbers. Originally the combo was a full TFS combo, heads UNmilled, shorty headers and stock fan. Now I milled heads .020", added electric fan, FTI cam & new valve springs, longtube headers and removed some weight. All for an extra 2mph at the track. Since swapping cam and LT's, the car had a big lean problem so I swapped to a pro m 80mm maf, didnt help, then I put in 30 lb injectors with the c&l meter. car felt faster but of course the idle was crap. All this stuff I did with no huge increase. I should have kept the TFS cam and just threw in longtubes. I would have probably saved like $700 and gone just as fast. The $600 dyno tune was kind of a waste and I didnt gain much power, but I dont think the shop is that great at tuning. Ah, sorry for the rant :-/

Mike

 

[Michael Yount]

The problem is Mike, unless you degree it, you don't know where it's installed at. You're just guessing on the install, and you'd be guessing on the re-install, unless you degree it. When you say "but installing it at 0 should be 106 centerline" - you're assuming all is correct with the cam, gear set, crank and block dimensions. That's rarely the case. As I mentioned in the other post, I helped a fellow with his FTI combo who installed dot to dot. When we went back and checked with a degree wheel, it turned out dot to dot was 4 degrees off of what the suggested install should be. If the cam is ground a degree off, and the pin is a degree off, and the crank key is a degree off and the crank gear is a degree off and all of those stack the same way - Voila - you're 4 degrees off. It's not uncommon - some of the reputable builders on here will tell you that it happens all the time. For a stock cam/stock engine, dot to dot is fine; but if you're building for performance, you just have to degree unless you don't mind taking the risk on the guess. You could re-install and move the cam timing around. And it could be better. The point is, unless you degree it to know exactly when the intake/exhaust is opening relative to Ed's suggestions - you'd just be guessing. And you could just as easily guess in the wrong direction and make it worse. And, remember, if you retard it relative to where it is now, the exhaust valve will be closing later, which will reduce exhaust piston to valve clearance. If it were me, and that clearance was close before, I'd want to remeasure after the timing change to be sure I had enough exhaust clearance. And, that link also said if you had a cam modeled for your set up, you should install it where the modeler said to install it. There's got to be another Stanger on Long Island (right?) that will let you borrow a dial indicator and a degree wheel. I'm gonna help another buddy degree his and measure p to v later this week using my stuff.

How many miles on the bottom end Mike? Did you run a cranking compression or leak down test before you made the changes?

 

[Grn92LX]

Never did a compression test, I should though. I have a tester. I have about 125k on the stock short. I do get some blue smoke sometimes when I get on it. My friends have verified this when their behind me I was messing with the car before and I advanced the timing 2* and it felt good, cant tell if theres much of a difference, but it didnt't feel slower. I doubt they put enough timing it in anyway as they were shocked when I said I ran 18* timing. Only problems I can think of are not enough timing, cam off or shortblock is showing its age. I am crazy lost with this cam degreeing thing and theres no one around here that could help me. Buying the $186 degree kit from comp is NOT an option right now. Money is real tight now as I been laid off for a few weeks (I do union electrical work and its slow now) I dont have the money to be throwing at the car to "try" and fix a problem. Any other questions, comments, lemme hear 'em.. Still waiting to hear from Ed C.

Mike

 

[Michael Yount]

I bought my degree wheel from the local speed shop for $16, my dial indicator and magnetic stand from Harbor Freight Tools for $26. I used a piece of a coat hanger as a pointer. I made a positive stop out of an old spark plug by breaking the innards out of it, hacking off the ground-tip, screwing a bolt into the business end and cutting the head off the bolt. I wouldn't pay $186 either; but you don't have to pay that much.

However, I suspect the HP that's gone missing has much less to do with where the cam or ignition timing may be, and much more to do with that smoking, high mileage short block. And that's gonna cost alot more than $42 to fix. Good luck though.

 

[Ranchero5.0]

Ditto that.

Not really enough total combo info to troubleshoot why it may not peak higher. My '93 had trouble pulling above 5200 because the ignition wan't up to the task. That may tie into your timing issues, plus the ballancer may have slipped a little. The '93's was wobbling so I swapped it out with a new Ford stocker for $99. Used to run 14 and now it's happiest at 16 or so. Seat of the pants running seems the best way to troubleshoot something and then dyno tune it to finish it off once the engine is done forever. Until then you are wasting your money. I do the $75 three pull job each summer for braggin rights and to see just how well my mods are working together.

BTW with the combo you have a 5psi base blower will make you absolutely happy. My dyno curve is the same as your's down low but it takes off above 3k due to the boost.

Jamie

 

[Michael Yount]

Except that, of course, if he bolts a blower on that unhappy shortblock - well, can you say blow-by-bye? Of course, a bit of boost would render the cylinder seal even less effective sooner meaning a bottom end rebuild that much sooner. It's a win!

 

[Grn92LX]

You think my shortblock is that bad? I dont think it smokes everytime I get on it, but im not 100% sure. I dont even feel like messing with the cam now anyway. I'll just leave it as is. My stock T5 is dying so it's not like ill be racing the car much. I think as is, the car will run better if I went to the track but my T5 is a time bomb right now lol. Good thing I have a daily driver, im tempted to take it to the track to see if it improves. I just hope the Union halls calls me soon with some work cuz money is tight right now. Michael, you got me thinking about a 10.5:1 347 with another Ed cam and ported trickflows now lol thanks!

Will a compression test tell me anything about my shortblock?

Mike

 

[Michael Yount]

Don't know what kind of shape the short block is in - but, from what you've said - it smokes some especially when you get on it, it's got 125K on it, and with the mods you're asking it to do even more than it was doing stock. You need more data in my opinion - leak down test probably - to get a feel for the actually condition of your cylinder seal. But, if you're generally happy with the way it's working - I'd just drive it and enjoy it. And know that when you can afford it, it'll probably respond nicely to a 'freshening up'.

 

[Grn92LX]

My car doesn't smoke bad for the record. It will ONLY blow some blue smoke when I get on it hard sometimes, not always. I been thinking and I really don't think the shortblock is my problem. I think 2 possible things. 1) cam may need to be degreed and then installed on the 108* centerline. It may also be fine where it is. 2) I been thinking my trickflow street intake with a 3/8" spacer and small 65mm TB might be a restriction up top. I been contemplating a track heat upper and 75mm TB swap. car is NOT a daily driver and I don't think the track heat upper & 75 TB will hurt low end much but I do think they will help me up top which in turn will get me more power and et/mph. Those mods will also probably need a 410 gear. Correct me if i'm wrong, but either of my options should extend the powerband a bit higher, correct? Thanks,

Still haven't heard from Ed yet.

Mike