chevyv8guy

so after i did my v6 to v8 swap i got to enjoy my car for about 4 days...until the cam shaft shattered destroying the internals of the engine...so back out comes the engine and in goes a fresh built engine using my block and heads

specs 350 2 bolt main
.30 over
flat top pistons
lunati hyd cam 00010 lk
Adv. Duration: 292°/292°
Gross Lift: .480''/.480''
steel crank
edlebrock performer intake
750 q-jet carb
ported and polished 416 heads
11:1 compression
hedmen shorty headers
3" flowmaster exhaust
here is a video of it idling after cam break in was finished and carb was being tweaked let me know what you guys think!!

http://www.youtube.com/watch?v=NkSmdX8YxmA

Twin_Turbo

iTrader: (25)

cam shattered?

chevyv8guy

yep...the cam gear was destroyed sending metal all into the engine and every lobe squared off and a big crack in the middle of it i took it to my engine builder and he said he has never seen a cam gear shatter like that

1gary

What was/is the cam manufacture's recommendations for the dizzy's gear??.

chevyv8guy

No clue the previous cam that was in there I had no clue what it was but found out it was a comp cam not sure of specs but my dizzy gear was fine and my engine builder said I can use the dizzy I have now with my new cam and have no issues

1gary

I am suggesting that with every failure and especially with a dramatic major failure like you had,there is a cause and the effect you found.A call to the cam manufacture given the engine problems you have had already about what you are using is appropriate.Who is your engine builder??.Northeastern??.I know afew in your area.

chevyv8guy

I go to precision automotive and he said it looked like it was an old cam to start with I had bought a brand new dizzy a month ago
And asked if it would be perfectly compatible lol

Twin_Turbo

iTrader: (25)

any chance you are running a stupid high oil pressure???

chevyv8guy

Nope oil pressure was dead on the cam was old and prob couldn't handle the new dizzy the teeth were all chewed up and every lobe was squared off showing it was installed wrong I had bought the engine with "only run time on it" with the with the intake off I removed the heads and everything looked clean and new until the cam went and I could see it was old the engine has been completely rebuilt and I have maybe put 80 km on it lol

1gary

Nope- does not sound like not a old cam.I have seen used cams swapped into untold engines.Those kind of events like what you now saying sounds now more like a flat tappet cam and poor or no break in procedures or mixing up tappets on a reinstall or spun cam bearings.More likely the first two.

One thing I didn't ask you is did you upgrade to a hydro roller on you current engine.There are tons of advantages using them.

Al Weyman

Roller cam needs bronze gear problem??

1gary

Al I don't know what he had/has.He never said.

Al Weyman

Could be his problem?

danielsan

Curious what that would mean?

Twin_Turbo

iTrader: (25)

The cam drives the oil pump via the dizzy, if you have a stupid high pressure @ idle, there's a chance you'll strip either the dizzy or the cam gear and if the cam wasn't that great a quality to begin with as can be deducted from above posts it might have been a reason for this failure

1gary

I have read this three times and it does kind of bug me some.Maybe you could post what kind of pressure your talking about at idle.True enough volume is directly related to RPM,but so is pressure.I do think we all understand how the oil pump is driven.

Al Weyman

I have high cold oil pressure when I fire up my race engines (90lbs +) but am running a 5/40 weight synthetic and am careful to warm it up slowly before giving it any revs, maybe with a 20/50 mineral oil in there it would put a strain on the gears I did burn out an electric drill once winding up the oil pressure when 2unning 20/50 oil so there is a hell of a lot of strain there.

1gary

Ya know Al there is so much info missing from this O/P in this thread.Your race deal I would "guess" that you have a high volume/high pressure pump with as you said race oils.The O/P's car I am "guessing" it is a stock pump and some 10w sumthin oil.

So Al-I'm out of this until the O/P posts again and I am thinking even if he does,there is a high likelihood that he doesn't have the info to fill in the blanks.

Al Weyman

Yes agreed something is odd on this one.

Twin_Turbo

iTrader: (25)

Well, let's say you have an engine with tight bearing clearances and run a high pressure/high volume pump. Have seen them w/ stupid high pressures like 80+ psi @ idle. That's about 3 times of what you'd want. Cold oil makes it even worse.

chevyv8guy

Hey guys been away for a few days
as for the oil pressure it was at 75-80 psi which is about normal and about 60 psi when warm at idle and i have the same now with the rebuild as well as a new mahley oil pump
the cam was not a roller and its not a roller now so no bronze gear its flat tappet as i stated above
if i missed anything let me know i will try and dig out the old cam and snap some pictures for you guys

Twin_Turbo

iTrader: (25)

that's not normal, that's pretty high and completely unnecessary. Not saying it's the casue but it probably contributed to the problem. If there is some issue like improper gear meshing, the dizzy bottoming out on the pump causing an issue etc. it's not going to help at all. Want to see pics of broken cam.