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What's wrong with this cam head setup?

Rocketkid

Member
Joined
Jan 13, 2002
Messages
17
Location
kirkland, wa
Corvette
1981 Black
We are buiding a stroker engine, we are using "Dart Heads - Iron Eagle Assembly 200cc Runners, 2.02/1.60, 72cc" and cam, after 1500 miles we got stuch lifters about 5 of them they messed up the cam.

We put in a new cam the specs on the new cam are
" Operating Range: 2000-4800 RPM
Duration Advertised: 280° Intake / 290° Exhaust
Duration @ .050'' Lift: 214° Intake / 224° Exhaust
Valve Lift w/1.5 Rockers: .442'' Intake / .465'' Exhaust
Max Lift Angle: 107° ATDC Intake / 117° BTDC Exhaust
Lobe Separation Angle: 112°
Open/Close @.050'' Cam Lift: Intake - 0° BTDC (opens) / 34° ABDC (closes)
Exhaust - 49° BBDC (opens) / (5°) BTDC (closes) "

After 20 miles the lifters sounds like they are stuck again.

We have roller rockers installed on the heads.

any ideas why this is happening?

sam
 
well the first thing Id say is that a stroker engine can mean alot of things , and you didn,t mention the compression ratio, rear gearing or trans used, but ILL assume your refering to a 383, stroker version of a 350sbc.
if thats the case a set of 200cc iron eagles is not a bad choice, but the cam seems alittle too mild for best results.(but without knowing the other factors its hard to judge)
now your problem with the cam having the lifters & lobes go flat can be from alot of problems, did you buy a complete kit with matching components or just a cam, and lifters, that may or may not match???(theres some real crap parts out there,and your usually better off buying a matching component kit from a company thats got a reputation to uphold) (theres some good quality parts that are less expensive but generally the bargin basement stuff is priced that way because IT WORTH LESS AND NOT UP TO TOP QUALITY LEVELS)
some of the non-name brand imported parts are far below decent quality levels
you didn,t mention if you totally cleaned out the engine after the first cam went bad to remove the metalic crud thats ALWAYS left over, nor did you mention the break in procedure, did you prime the oil passages and adjust the valves and ignition timing, correctly?
or if you used a good mineral base oil with a high zink content like VALVOLINE that helps prevent wear,if a good MOLY assembly lube was used?, if E.O.S. was used, if you checked ALL THE CLEARANCES and WHAT the coil bind height was? did you REALLUY CHECK THE CLEARANCES or just assume they were correct because the engine rotated without binding up???? did you keep the rpms over 2500rpm for the first 15 -30 minutes? what was the oil pressure and engine temp???? what was the valve lash or preload??? what was the ignition timing set at?? did you change the oil and filter after the first few hours?, did you get the valve lash/preload adjusted correctly?

read this

http://www.cranecams.com/?show=article&id=2

http://www.usaimports.co.uk/Mopar_Tech_Pages/hydraulic_cam.htm

http://www.348-409.com/fireup.html
 
Hey Grump, great posting. That is a good checklist for anyone doing a cam swap/engine rebuild.
Hey Rocket, pull the valve covers, disconnect the distributor have someone turn the engine over and watch the rockers to see if the valves are opening and closing. Make sure you didn't shortcut the valve adjustment procedure. I've done that. (and just about every other mistake) peace Bud
 
? verified: lifters rotating ?

Flat tappet lifters (both solid & hydraulic) MUST rotate in their bores.

Have you verified each lifter is rotating when under load of valve spring? You should VERIFY BEFORE you install intake manifold and AFTER all pushrods/rockers are adjusted. Mark top of each lifter & its bore with a sharpie ... turn the motor by hand through 2 full revs ... each lifter should have rotated about 1/4 turn ... if not, you have problems. This is done PRIOR to break-in ... done while motor on stand.

Lifter bore may have dirt / rust / burr etc ... preventing its lifter from rotating.
JACK:gap
 
Grump,
I'm going to try to answer your questions to the best I can.

Stroker = stoker cam kit yes 383 like you mentioned of 350sbc.

The cam and lifters are a set, rockers were bought sepearte.

I changed the oil on the car before we restarted with the new cam. Not sure how else I can clean out the engine short of taking it apart.

Breakin: We ran the car at 1500-2500 rpm for about 15-20 minutes

I did not prime te oil passages.

We adjusted the valve with the valve cover off when it started. remove the lash and 1/4 turn. We also did the timming.

The oil temperature leveled at 260 degrees

We used the assembly lube that came with the cam.

We didn't check for clearance.

Oil pressure was 6.5-7

I think the problem is the lifters are collapsing then they are ruining the cam, when we took out the lifter 5 were collapsed which messed up the cam the first time. Now after 20 miles the last 2 miles the same sound came back which I think there are lifters collapsed again.

sam
 
"The oil temperature leveled at 260 degrees..."

"did not prime the oil passages"

" We didn't check for clearance....."

"Oil pressure was 6.5-7...."



OK YOUVE GOT PROBLEMS, oil doesn,t get to 260 degrees unless youve got low oil flow voluums and or a cooling system thats at best marginal.....
theres no mention of E.O.S. or VALVOLINE or similar high zink oil used, theres no mention of you checking the oil level up to the recommended levels,theres no mention of a quality filter, you should be using a running water hose flowing water thru the radiators finned surface to keep the engine coolant and oil cool
at a MINIMUM now that youve destroyed two cams and gotten the resulting crud into the engine, I strongly suggest pulling the engine down and running a bore clean brush thru all the oil passages and replacing the bearings
both the 260 degree oil temp and the extremely low 7 lbs of oil pressure indicate a problem,(probably due to crud in the old bearings from the previous cams failure) not checking the clearances and not checking the lifters spinning freely in thier bores plus the uncertain valve/lifter preload are major potential problem areas, not adding the E.O.S. and running a high ZINK content oil adds to the problems potential.
yeah! I know thats near the last thing you want to hear!
but slipping in a new third cam without fixing the problems is a great way to have that third cam fail also!
 
"not adding the E.O.S. and running a high ZINK content oil adds to the problems potential."

I normally pour the E.O.S. in just before starting the engines cam break in,procedure. because I want to make sure that nothing in the oil/E.O.S. mix can settle out from sitting over a long period of time. now if your running a flat tappet cam you should have also used a moly cam lube on the lobes and be useing a mineral base oil for the break-in procedure, VALVOLINE RACING OIL is a well known high zink content oil ,BTW, and youll need to do an oil and filter change after about the first 2-3 hours running time (vary the load and rpms constantly, but keep between 2000rpm -5000rpm) to remove that moly cam lube from the engine after its served its purpose of protecting the cams lobes and lifters at start up, aND AS THE LOBES/LIFTERS LAPPED IN. MOSTLY to prevent that moly grease and E.O.S from potentially partially clogging the filter after that mix cools down,but also because both those lubes might leave deposites in the combustion chamber ,over time that might aggravate detonation.
even G.M. suggests that E.O.S. is not a great long term oil suppliment, and that its main function is to add extra oil film strength durring new engine break in.
1052367
ENGOILSUP any large chevy parts department
EOS - Engine Assembly Prelube<BR>Specifically formulated as an engine assembly lubricant. E.O.S. provides outstanding protection against run-in wear and piston scuffing as well as run-in camshaft lobe and lifter scuffing resulting from insufficient lubrication
1052367.jpg

don,t forget a few magnets in the oil pan goes a long way towards trapping unwanted metalic dust formed from the cam and rings lapping in durring break-in that might otherwise get imbedded in your bearings or cause other problems
heres the magnets I use in every engine
http://www.wondermagnets.com/cgi-bin/edatcat/WMSstore.pl?user_action=detail&catalogno=0035
 
Grumpy,
So why would the lifters collapse, I understand the lubrication issues, I don't see how that caused the lifters to collapse?

sam
 
lifters DON,T just collapse, they generally fail due to improper clearances, lack of oil pressure and voluum or improper adjustment. your lifters didn,t collapse, the lifters failed to lap in, or the cam lobe wore,but the chances of a lifter failing if properly installed and adjusted is rediculusly small,to have several fail, within minutes is surely a sign that clearances or lubrication were not correct, Id suspect that the valve lash clearance(lifter preload) was overly tight or there were clearance issues. the fact you had a good deal of metalic crud left in the engine from a previous cam failure only adds to the potential problems.
read this

http://www.cranecams.com/?show=article&id=2

http://www.usaimports.co.uk/Mopar_Te...raulic_cam.htm

http://www.348-409.com/fireup.html
 
Grump,
You have been very informative thanks a lot for the information, and thanks to everyone that also contributed to this thread, I think I'm at a point that I'm not comfortable to continue or attempt to fix it myself, I will be taking it into a race engine builder shop next Friday, I will let you know what they come back with.
 
after you rebuilt the motor did you put threaded or push in plugs for the oil passages in the rear of the block?? i have seen lots of guys that over cut the threads on the three holes and run the plug in to far and choke off oil supply to the cam.
 

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