Dist/carb tuning question

eric lavine wrote: dont give away that 750 just yet....

Do you know of someone who may want it? Or is that someone maybe me?

dont give away that 750 just yet....

boat dr wrote: Eric, I can see it now.......             GIBBS ENGINE SUPPLY               1-770-536-2328         "You Smokem We'll Strokem" Greggs Inboard Big Block School

That's funny!!!   LMAO

We'll get billy mays to advertise it..."Only $19.95 for your first free lesson, and if you call right now we'll even throw in a slightly used 750"?!!?

i was on a boat today with a merc, BBC righty, I was there to install his 4th trans, he got rid of the guy that did it the first three.....this officially is number 15 for the fix it again club. the day started with the trans tipping over in the back of my suburban and puncturing a hole in the 1 gallon jug of Dex/Merc and you know where it ended up, then to top it off we were at full cruise after i found his trans lines were with the flow and the alignment out side to side .021 and i told him to run it like he normally does. I had my face about 2 feet from the dipstick and all of a sudden the dipstick launched and out came 180 degree oil right into my face...that hurt with momentary blindess. The reason it launched to find out was i was thinking man is this thing screaming, he told me his tac was off, so I put my photo tach on and found he was constantly running the boat at 4700 rpms and one reason was the smaller prop. typical tow boat owner. what happens is the oil pump spins engine speed and creates way to much flow over 4000 rpms. this obviously was part of the problem along with the MA and cooler line switch, just thought i would post cause he wants me to rebuild the engine over the winter and i told him i wouldnt but i knew of someone that would and if he would be willing to ship it to Atlanta

Greg, you are very welcome. Would do it over again in a heart beat for you, 'cause you would do the same for me.....Nuff Said.....
We are all here to do different jobs,just have not found the right job yet, but still lookin'..................Boat dr

Side note Greg, Gotta a phone call from PCM yesterday from Mark Sneider,He had some loose time that he spent with me on the phone.If you want to know more about the conversation and the info I gained, give me a call.Will share what I learned from him,very interesting conversation........Billy

but can't it be determind by watching which valve moves at what time and work backwards since the info isn't there? Basicly you want to know if the valves are closed and on the right stroke, i.e. compression when they are suppose to be and what the actual order is. Granted this is going to take a little time without the info but then if he all ready had the info he wouldn't need to verify it.

I'll look it up Chris, but it's much more fun when you explain things!   

Me too Eric...cam swap and piston twist!

79nautique wrote: you really need to check and see if the cam is degreed correctly before you start spending money guessing on stuff but then that's too late too. And that the firing order matches up with the crank's

I'll do it if you'll explain it to me.

I'm not going to talk out of school, but I think this cam from PCM is unique and I think this mill was carefully thought out. We'll see...

eric lavine wrote: TR, im assuming and the point is there is a difference in between the same spinning different part number cam, i dont know the difference and was using it as an example as to if the machinist thoughts were we could use a normal cam and just switch the firing order and it will be fine...thats not the case, i know there is a difference in the cams but what i dont know.....but what i do know is, there are 2 cams for this engine under 2 different part numbers and the cams both spin the same direction i suspect with the comp ratios being so close that the it also has something to do with the cam being degreed wrong. I fully understand the problem and i am merely making suggestions and not sending him on a wild goose chase.

Gotcha- the difference between the LH and RH cam would be pretty significant, and its possible that the machinist got confused since they both spin in the same direction.

If it is in fact a LH cam in a RH engine, Im pretty surprised that it ran up to 4k RPM- or that it ran at all. Trying to start my 302 backwards (LH starter) didnt work very well. Im wondering if Joe is possibly right about there being a wiped lobe or 2.

TR, im assuming and the point is there is a difference in between the same spinning different part number cam, i dont know the difference and was using it as an example as to if the machinist thoughts were we could use a normal cam and just switch the firing order and it will be fine...thats not the case, i know there is a difference in the cams but what i dont know.....but what i do know is, there are 2 cams for this engine under 2 different part numbers and the cams both spin the same direction
i suspect with the comp ratios being so close that the it also has something to do with the cam being degreed wrong.
I fully understand the problem and i am merely making suggestions and not sending him on a wild goose chase.

Greg, i think i may be misleading you with cam timing, im reffering to if the key or the pin is off on the gear causing the cam to be advanced or retaraded where it connects to the gear, sometimes on cams you have to use offset keys to get the cam back in time, but it is minimal with the key. I dont mean you you didnt hit the timing marks on the gear (or did you) lol
My point about the PCM cams were they both spin the same way and they are both are under a different part number and if the difference was the firing order you merely would switch the firing order not re-design the cam to match the firing order.
I had a problem with a BB cam a few years ago and in 3 hours the cam was a broomstick, the leading edge of the lifters acted like a lathe tool bit and ate it right down to nothing....i still to do this day dont know what happened and Crane of course said it was improper break in...thats my excuse with tranny's lol
I kept adjusting the rockers and they kept loosening on me....you should've seen the metal in that thing btw, i went to a roller after that.
hang in there you'll solve the problem

I once read "Smokey Yunick's Power Secrets" in this book he claimed by running your wrist pins bacards you gainned a longer dwell time at tdc building more drive on the power stroke.So does it really matter which way the pins are off set?I think the cam might just be installed poorly in respect to timing I'd want to verify that and might take considerable thinking and sketching with a standard cam running backwrads to the crank.Do you have a cam card on this piece?

Munday

TRBenj wrote: eric lavine wrote: All i can say is: in those years for the BBC thorough PCM there is a left handed cam and a right handed cam under different part numbers, why would they not use one common cam in both engines seeing that the cams spin the same rotation? Regardless of which way the cam spins, the firing order is specific to the rotation of the crank, no?

I think it is specific to rotation and not cross-referencing the PCM part #'s is a big mistake I won't make again. I trusted the shop to research it after I gave up on the roller conversion; I'll have a more 'direct' chat with them when the final verdict is in. I got a classic blank look this morning when I talked to them...apparently a little more than average thought went into the make up of this mill.

Back on my other thread, either crane or comp explained to me that a RR cam is a mirror image of a LH cam spinning the same direction. I think the chevy cams and dist's from this time period all behave the same way; CW for the dizzy and 'standard' for the cam. It's where the lobes are and isn't there a leading and trailing edge of the lobe? I'm no expert, but may soon be on this engine anyway...soaked up a lot of info through all of this.

I ordered the PCM cam from Woody and will compare the 2 when I get that far.

Thanks Woody for your time and help!!! I don't get in your neighborhood very often, but I will stop by someday to say that in person.

For now I'm decided on the piston turn and I even think I understand why. While I'm in there we'll all see whatever else I got the pooch on?!!?

I really would have put my money on having more trouble with the patch!

eric lavine wrote: All i can say is: in those years for the BBC thorough PCM there is a left handed cam and a right handed cam under different part numbers, why would they not use one common cam in both engines seeing that the cams spin the same rotation?

Regardless of which way the cam spins, the firing order is specific to the rotation of the crank, no?