cv67

http://forums.corvetteforum.com/c4-t...eeded-pic.html

In stabbing the dist in today to run it once again a tooth off
Actually 2

So stab it again, its off again.

Noticed some side to side slop when the dist was in. Too much
(dist was sitting too high)

Thought it was the housing at first but intake measured the same as a TPI..and WW7s. So its good.

Pulled the gasket off the dist and dropped it in, barely .010 clearance


Remembered I had to use a .120 thick intake gasket due to a lot of head/intake milling to get it to seal. Swore we used the same one on the 350 so I never thought to double check it once a new rotating assy was put in. Oops.

Fel Pro about 1/16 thick

So math is off.

Gear riding too high on the cam gear.

Just from spinning the motor over some to try and start it Fd up another gear. Just starting to see some wear, same pattern.

There goes another 7 qts...and a $60 gear.

Taking it in to the machinist to have him turn the housing down some.
This HAS to fix it. Better.


Never assume anything.

WW7

Once you get your distributor at the right height maybe you should start using a composite gear.. These will have almost no wear and can be used with any cam gear out there...They are a little pricey at $100.00, but well worth the money, especially since you burn through $60.00 distributor gears pretty quick.....WW

THE 383 admiral

OE or aftermarket cam... I know for a fact there are manufactures out there
The cam gear is off 2 deg from bogus cores

cv67

Isky 8620 Billet.

Sketchy about the composite (although many have good luck)saw a Comp compsite gear at the shop last week with a good portion of the teeth ripped out of it.

Maybe once I know this wont have wear issues maybe switch-

W:

As it is now there is maybe .010 clearance bet dist and intake.
Gasket is .046 thick so I was minus .036 at least +endplay min?

Sent pics of the new gear off to Morel to get their opinion on the condition of the gear.

Its always some stupid little detail/small $ part that takes everything else out. He didnt check it I assumed he did.


Thats the painful part of hot roddin.

Next one Im doing myself

GREGGPENN

If it bottomed out and had .010 gap between intake and dizzy housing, and you used a .046" gasket, wouldn't you have .036" up/down play? Do you really need to shave the housing to get more?

I thought the main thing was to make sure your weren't bolting the gear into the cam so it caused pressure at the mess point?

cv67

Whats happening is the gear needs to go down at least that much more(probably farther) to even fully mesh properly so its riding high on the tooth as of now.

You start adding aftermarket intakes heads etc with different thicknesses this really needs to be checked.

Caboboy

Groan........

the joy of hot rodding

Cliff Harris

Is your oil pump shaft holding the distributor too high? Maybe the groove in the shaft is too shallow.

383vett

Not to flatten your tire, but as long as the distributor is not bottoming out on the oil pump shaft, the vertical positioning of the distributor gear in relation to the cam gear is not that critical. The way the gears mesh allow for a large tolerance.

GREGGPENN

So, here, you're not saying the gears hit, make it stop, and leave .010 between the intake and dizzy base?

To, me it makes it sound like you need enough "gasket" to fill that .010" --plus-- add some add'l spacing to create up/down play (of the internal, rotating shaft).

Turning the base down would only require a thicker gasket.

Churchkey

Yep.

Not telling you what to do just stating what works for me.

Suggest installing the dist with a gasket then grab the the rotor mount & check vertical free play. If you have some your good to go.

If a new cam is installed & you did not dress the cam gear with a stone to kill the sharp edges it will eat a brass gear quickly in a wet sump engine. Suggest installing a stock dist gear & run the engine for an hour or so to "break in" the cam gear.

After the cam break in reinstall the bronze gear & set the timing.

After the timing is set mark the dist base at 90* to the cam & just above the cam. Remove the dist. On the lowest machine surface of the housing above the dist gear machine a slot approximately .030 x .030 in line with the mark you made on the base. Your oil pump will now supply oil to the cam gears & the brass one should live for an entire season. You may want to check it from time to time as they have a short life span in a wet sump motor.


GL

cv67

Gregg with the dist in there is only .010 clearance seems like not enough
So with a .043 gasket the gear is riding higher up.

Anyway I have a moroso shim kit Ill play with when I get it back.

Churchkey interesting. Ive heard a few people talk about dressing those gears. Id expect that was QCed before it left maybe not.

If it still wears some Ill give it a shot with the steel gear. Or Iron?

If at that point I have an issue think the whole motor is coming out not only to shove this cam up someones hind end but to tear it down and check bearings cyl walls.....and get rid of the HV pump.
Might be a waste but Im picky would answer some questions

Sent some pics of the gear to Morel who makes the AMPCO-45 gear they say its fine to run it. Tested the hardness it was night and day compared to the first gear.

Keep you updated probably wont get it back til next week.
Just wanna drive the damn thing. Track event in Mar Ill miss was hoping to have it all run in/tuned by then.


On the slot...almost had him do it but held off.

I put some Comp Cams lube on the gear before putting it in.
Just from cranking it over 1/2 dozen times it was all washed off and doused in oil but think once its timed may do it anyway cant hurt.

383vett

Here's the area Church is recommending the distributor slotted. I did mine when I was running a bronze gear, and had no problems. It definitely won't hurt anything. It will have a negligible affect on oil pressure or flow. Oil will just drip on the gears. Willie

mtwoolford

subscribed

ex-x-fire

They make dist. collars, just disassemble the dist.take it to a machine shop & have the old one turned down. The new colar goes on & is held in place by 3 set screws. Then you can adjust it up or down alittle, might want to open up the oil passage too.

856SPEED

when I put my engine together, it (ZZ9 roller cam) chewed up the stock ditributor gear, leaving me stranded on the highway. Someone forgot to inform me the stock gear would not work with that cam, and fortunately it did not grenade the freshly rebuilt motor with fine particles of metal. My mechanic directed me to purchase a "mellonized" gear and not a bronze gear, that was his opinion. I have running a melonized distributor gear(GM part he ordered) ever since (several years) with no issues at all. I am not sure this is completely related to your particular situation, but I thought I would share this with you anyway.

cv67

Souds like the melonized is too hard

May look into this.
Even with everything right not sure I like the idea of anything wearing prematurely. Its a street car not a race car torn down all the time.

http://www.summitracing.com/parts/LUN-89026LUN/

I will check the pattern when I get the dist back next week. If its **** maybe Ill give it another shot. If not it goes in the trashed parts pile.

383vett

If you are having an iron gear pressed on your camshaft, just go with a standard iron gear. You should be fine.

WW7

Having an iron gear pressed on is the best way to go , bronze dizzy gears are only suppose to last on average around 1,500-3,000 miles with billet cams from what I have read.. That's not much for a street driven car.. A melonized gear is just an iron gear with a melonized ( hard ) coating and was developed for steel 5150 stock cams . This won't work with a billet cam gear..The idea is to always have the distributor gear made of a softer material then the cam gear, this way the distributor gear is sacrificial. WW

GREGGPENN

For those considering this mod, pay close attention to the picture above. And, don't go too crazy with your cut. I did.

I didn't end up installing my mistake. Actually, I figured out what I'd done within a few minutes after I was done. I read about this mod in this (or another) forum and thought "Perfect! What a great idea!". Trouble is, I didn't think it thru very well. When I showed this to my shortblock builder, he had quite the chuckle.... Hope you do too! :o



BTW...The best place to cut this type of groove is on the side where the dizzy and cam intersect. And, in case you don't figure out my mistake, don't groove the top ring and don't make such a deep groove!!!!