Stupiderest question ever

[speedy400]

This has got to be the stupidest question I have ever asked... I ordered a set of andrews cams off ebay, they were made for a 78 gs1000, going in my 82 gs850. Slipped right in without a factor.... But 2 questions arrose. A. Why are the lobes diffrent size and shape on the outer ends of each cam than the inner 2 lobes?!? I didnt get 4 valve cams did I? This dosnt make much sence to me concidering zuki didnt come out with 4 valve heads till the 80s right? And for all the 4v heads I've worked with the cam setup is totally different(one lobe for each valve).
OK now if all is well and I did get the right cams.. Where's the timing marks on the cams? Should I be reffering to the little arrow on the cam sprocket? Just making sure. Thanks guys! Been a Huge help!-darren

 

[Dink]

Yes you do time them to the arrows; with stock cams!!, this may not be the case at all with aftermarket cams.
You may need adjustable cam gears and a degree wheel to "dial" them in. is there a notch in the ends of the camshafts? like on the stock ones?
Dink

 

[speedy400]

I have all the tools to degree them including adjustable cam gears that came with them, but I'm still not sure on if they are even 2 valve type cams! Is it normal to have the inner 2 lobes diffrent shape than the outer 2 lobes on the same cam?(my motor is an 850 2 valve, dohc motor). Please reply asap! thanks-darren
ps- yip notches at the end of the cams like the stockers.

 

[Dink]

Yes it is possible. Not sure I think it is a good idea, but it is possible.
Dink

 

[BadBillyB]

What grind number are they. Its on the end of the cam. Althogh Andrews does not make these anymore, the specs are, I'm pretty sure, still listed on their website. I was running a 4S/3S set up in my bad ass street motor in the early 80's, with an 1175 MTC kit. Heres a pic of the 3S Andrews cam, it looks pretty symetrical to me

 

[Billy Ricks]

I have all the tools to degree them including adjustable cam gears that came with them, but I'm still not sure on if they are even 2 valve type cams! Is it normal to have the inner 2 lobes diffrent shape than the outer 2 lobes on the same cam?(my motor is an 850 2 valve, dohc motor). Please reply asap! thanks-darren
ps- yip notches at the end of the cams like the stockers.

It's possible the cams had to be reground and that's how the two inner lobes ended up the way they are. As long as they provide the same lift and duration then it should be okay. The four valve heads only have four lobes per cam with forked rockers to depress both valves off of one lobe.

 

[speedy400]

Ok, heres what I know.. heres a andrews cams chart, the cams I have has 3s stamped on them, but seem to have a 2s grind.-darren

 

[speedy400]

Now here is some pics of the "exhaust" cam.. there only seems to be 1 cam thats really diffrent than the rest... which seems Very odd to me. The odd lobe is the cylinder #4 exhaust lobe... heres some pics.-darren

 

[speedy400]

2nd-darren

 

[BadBillyB]

It looks to me like either a wasted cam lobe or someone toyed with it on a cam grinding machine. I would be a little reluctant to put that in a motor. Heres a pic of the end of my cam

 

[speedy400]

hmmm, its weird because they all are simliar to your except # 4 cylinder's just seems like theres way mor material(the valve would be almost fully open longer).. Could you tape a pic of #4's on your cams? thanks very much for the help, very appretiative.-darren

 

[speedy400]

well this is just weird... the intake cam is perfect, so the only problem is that ONE lobe. on #4 of the exhaust cam.. and I looked at it to see if someone had hardwelded possibly some extra and reground it. There is still the weld lines from the (andrews) manufacture... so it was just made this way? why would they make it to have one exhaust valve stay near fully open a little longer than the rest? It cant be all the rest just got worn down because compared to other cams I looked at, all the rest of the lobes are correct. :-s :-s :-s . I guess it came out of a running gs1000, so should I just not worry about it and stick her in?-darren

 

[BadBillyB]

No, I wouldn't put it in the motor. If there is an obvious difference between the lobe on 4 and the rest, the cam is a paper weight. What is the grind # on the intake cam???........BadBillyB

 

[speedy400]

intake cam has the same #'s as the exhaust, 3s with grind of 2s it seems. Is there a way I could have a machine shop regrind the # 4?-darren

 

[speedy400]

Well... this is definetly not cool... I miked it once more, turns out the #4 is just Way Way wore out... like .1inches. thats why its rounded out more than the others... definetly not too happy, the ebay guy better take it back..-darren

 

[BadBillyB]

Darren, you do realize that these cams are rated at .424" lift and have a very high duration. These are "top end city" cams and require the use of "under the bucket" shims for reliability. For a street motor, the 3S intake grind has too much duration for good driveability, and 400" lift is about the max for stock lifter/shim set-up........I ran 4S intake with a 3S exhaust on my 1175 motor with good results, but I had "under the bucket" shim set-up. What is your engine set-up going to be ????........BadBillyB

 

[speedy400]

well, the cams seem to have a 2s grind, I'm not sure if its just because they are worn down to that point, but the lift is around .38, according to andrews specs I should be able to use stock springs and such. Basically a street top end performance cam as I understud. Thank you for approching the question though. The engine is basically stock though, 4-2 with cross over pipe, with megaphone style mufflers. UNI filter into jetted carbs and ported/polished ports. Its just ment for street rompin', so performance isnt a Huge deal for me. I was thinking of possibly seeing if I could have a machinist could hard weld some more material on that one lobe and grind it similar(smaller if anything) to the other lobes, like I said I'm not trying to drag it, so perfection isnt needed, just reliability... On that subject, how bad would it be to just throw the cams in and run it like this? basically what'd happen is the #4 exhaust valve just wouldnt open as fully as the rest, this'd be similar to basically having a restricted exhaust for 1 cylinder which I have seen done(sadly). Or is that just one of those things where "Darren... just spend the 400$ and get new cams" let me know, thanks-darren

 

[BadBillyB]

well, the cams seem to have a 2s grind, I'm not sure if its just because they are worn down to that point, but the lift is around .38,

How did you determine this when the cam says 3s on the end?? It also does not say Andrews on it like mine does. I am not convinced that it is even an Andrews cam at this point. Your exhaust cam is definitely a paper weight. What is the lift on the intake cam???, use a dial indicator to find out.....it's way more accurate with long duration cams........BadBillyB

 

[speedy400]

Andrews is cast into the cam, and it says 3s(like you said is suppose to have .424) on the ends, the intake cam is .39 . So it isnt possible to fix the exhaust lobe? or use as is?-darren

 

[BadBillyB]

Andrews is cast into the cam, and it says 3s(like you said is suppose to have .424) on the ends, the intake cam is .39 . So it isnt possible to fix the exhaust lobe? or use as is?-darren

The exhaust cam is toast. You have to use a dial indicator on the lobe to tell what lift it is, on a long duration cam. If it does not come out to .424 than it has been re-ground by someone and is an unknown product (with an Andrew core). A .424" lift cam requires race springs, special lifters, deeper than stock valve pockets and a careful inspection to make sure they will rotate in the head w/o hitting the upper edge of the lifter cavity....I feel your on the path to destruction and would suggest looking for some drop in cams that are more forgiving......BadBillyB