Cam card confusion
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Cam card confusion
I recently bought this camshaft Lunati #40121103
http://www.lunatipower.com/Product.aspx?id=3406
However here's the card that came with the camshaft above
Valve events on the card match the duration on the card so I'm a little bit confused
http://www.lunatipower.com/Product.aspx?id=3406
However here's the card that came with the camshaft above
Valve events on the card match the duration on the card so I'm a little bit confused
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- Dave Koehler
- Vendor
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- Location: Urbana, IL USA
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Re: Cam card confusion
Other than the numbers are 90 degrees off what is confusing?
Dave Koehler - Koehler Injection
Enderle Fuel Injection - Nitrous Charger - Balancing - Nitrous Master software
http://www.koehlerinjection.com
"Never let a race car know that you are in a hurry."
Enderle Fuel Injection - Nitrous Charger - Balancing - Nitrous Master software
http://www.koehlerinjection.com
"Never let a race car know that you are in a hurry."
Re: Cam card confusion
it does seem a little odd though the minor discrepancies won't be any real factor as far as the engine is concerned. Might just be slight tweaks on clearance ramps and when cam was built to card written.
Re: Cam card confusion
No it's just that I have never seen this mismatch before even though it's only one degree and 0.001" lift difference..
- Dave Koehler
- Vendor
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- Joined: Mon Oct 04, 2004 11:19 pm
- Location: Urbana, IL USA
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Re: Cam card confusion
Trust the card before the catalog.
Trust the Cam Doctor before the card.
Trust the Cam Doctor before the card.
Dave Koehler - Koehler Injection
Enderle Fuel Injection - Nitrous Charger - Balancing - Nitrous Master software
http://www.koehlerinjection.com
"Never let a race car know that you are in a hurry."
Enderle Fuel Injection - Nitrous Charger - Balancing - Nitrous Master software
http://www.koehlerinjection.com
"Never let a race car know that you are in a hurry."
Re: Cam card confusion
Yes, cam doctor tells lies.
I had a set of fkcud up reground cams a few years back (about 2002 but these things you tend to remember, all up it cost me a couple of thousand of $$$$).
Rang the place that made them.
Standard reply........the cam doctor says they're OK so they're OK.
But they weren't.
I'll never deal with that company again.
I found out the problem after spending many hours measuring and I learned so much in the process.
The cam card supplied was also wrong.
I won't mention names, just that they're based close to home.
I just hate being lied to.
But it wasn't just their fault, I paid a top workshop to fit them (wrongly too) when I should have done it myself. I couldn't have done it worse.
I had a set of fkcud up reground cams a few years back (about 2002 but these things you tend to remember, all up it cost me a couple of thousand of $$$$).
Rang the place that made them.
Standard reply........the cam doctor says they're OK so they're OK.
But they weren't.
I'll never deal with that company again.
I found out the problem after spending many hours measuring and I learned so much in the process.
The cam card supplied was also wrong.
I won't mention names, just that they're based close to home.
I just hate being lied to.
But it wasn't just their fault, I paid a top workshop to fit them (wrongly too) when I should have done it myself. I couldn't have done it worse.
- Dave Koehler
- Vendor
- Posts: 7205
- Joined: Mon Oct 04, 2004 11:19 pm
- Location: Urbana, IL USA
- Contact:
Re: Cam card confusion
Left us hanging there Joe.
What was the problem you found?
What was the problem you found?
Dave Koehler - Koehler Injection
Enderle Fuel Injection - Nitrous Charger - Balancing - Nitrous Master software
http://www.koehlerinjection.com
"Never let a race car know that you are in a hurry."
Enderle Fuel Injection - Nitrous Charger - Balancing - Nitrous Master software
http://www.koehlerinjection.com
"Never let a race car know that you are in a hurry."
Re: Cam card confusion
Dave Koehler wrote:Left us hanging there Joe.
What was the problem you found?
Several problems.
OK so Mitsubishi 6G72 DOHC quad cam 24 V
There's 4 cams each with 3 pairs of lobes using finger followers.
Being a V6 it's got 2 banks and the banks are pretty much mirror images of each other.
The first problem was myself, telling myself I'd be better off to get the local performance shop to do the job instead of myself. Reason being that I'm running a business of my own at the time (not a car related business) and I didn't have the time to take off and work on the car........a slave to my own business.
I had a spare set of cams I sent away for regrinding.
Problem no 2............ Receive cams back, no measuring required?
Problem no 3,................. drop car and cams off to kermit, who gets Scooter to do the job.
Half a day later , get a phone call. Do you have any spare valves.......we've bent 2.
Go home, find spare valves, drop them off.
Next day, pick the car up, pay the extra to remove head and change valves etc.
Problem no 4.........after about a week it starts making strange knocking noises from the top end.
Take car back. Some rockers have fallen off. Get charged again to fix it.
A week later, repeat.
This time asked for an explanation of what's going on.
Get lied to.
Ring the cam grinding company.........they go on about "preload" and "cam doctor".
Ring kermit and scooter?
More excuses.
About that time I decided that it's a waste of time paying a boy to do a man's job and if I want it fixing properly, I'll have to fix it myself.
At some point after that I would have pulled the engine (after refitting rockers on a nearly daily basis), pulled it all apart and started measuring.
Stock base circle is 30mm.
Base circle on reground cams was 28.5 mm on most of them but one "stick" had 2 pairs of lobes still at 30 mm base circle.
But they weren't the ones who's rockers kept falling off. Must have been a Friday afternoon job?
So that was problem no 5.
Back to the rockers falling off, with the reduced base circle, you need shims under the lash adjusters to get the geometry (preload) back to where it should be. It works out at about 2 mm with the rocker ratio.
When you shut off the engine, there's always some valves open, the lash adjusters for those valves bleed down overnight and when you restart, the rockers jump off.
Scooter didn't fit shims under the lash adjusters.
So that's problem no 6.
The 1/3 reground stick got sent back to get fixed and refitted (front exhaust I think).
The rear exhaust cam was the one dropping the most rockers and ended up getting some lobes gouged out so I sent another "stick" away to get reground to fix it.
Unknown to me at the time, the spare stick was a later cam with less lift but same base circle.
Problem no 7.
Some time later I decided to degree everything using a spare engine because I have never had adjustable cam gears (shouldn't need them if they're ground correctly?)
Base circle is easy to measure.
So is lobe lift.
So why does one cam have different lift from the other 3? (none of the cams fit the cam card supplied)
Then to degreeing.
Plot valve lift vs crank angle using dial gauge.
Both intake cams have a different profile to each other.
Both exhaust cams have different profile to each other.
That's down to the finger followers running on opposite sides of the cam, the cam lobes are the same profile when they should have different profiles.
Problem no 8.
After that I modified a set of stock cam gears (offset the locating holes) to make the best out of a terrible job.
How many ways are there to get it all wrong?
Ended up selling the heads, cams cam gears cheap and then upgraded with the "best" factory parts.
kermit is now doing online courses to teach people how to tune.
The local cam company has a really good reputation all around the world.
Don't pay a boy to do a man's job.
If you want a job doing properly, do it yourself.
If you want to be sure that the parts are right and the parts are fitted right, it's worth spending 20 or 30 or 40 hours measuring everything properly.
IF it's your own engine.
If it's just a customers engine........you won't.
Re: Cam card confusion
I'm thinking surely the cams were free, right?joe 90 wrote: Ended up selling the heads, cams cam gears cheap and then upgraded with the "best" factory parts.
I know for a fact some will, but one pays a premium for those hours...and that's okay.joe 90 wrote:If it's just a customers engine........you won't.
He who is in me is greater than he who is in the world.
Re: Cam card confusion
The last VooDoo my brother bought said 110 +4 in the catalog, the card said 110 +6. Who knows...
Re: Cam card confusion
I've measured cams (sliding foot ohc rocker design) and found many times they are different to what they are supposed to, mostly in lobe separation but also with duration and peak lift.
i also once ordered a cam that came with lobe separation about 95* instead of 110*, got a replacement didn't have time to fully check it it but some of the basics checked out ok. another cam by same company was 6 degrees too wide in LSA, they sent a replacement and it was closer but the lift and duration was suddenly different.
also another cam by different company this time, when i measured a cam and basecircle on a couple lobes was different. they sent a replacement and the lift was 0.020" too low
when you find it very often you start to doubt if its actually you but when you use new valvetrain bits, different used bits from the factory and use different heads and they tell you same thing .Also recently i know someone else found the same, cam supposed to be 108LSA, i guess 118 is close enough duration was about 14* too big to ...
i get that sliding foot rockers are hard to do as the rocker ratio varies and what not, but if its too hard dont make them. i think they must use the cheap aftermarket rockers to determine rocker geometry for the profile mapping, but those rockers are often different to the factory stuff so that would explain some of the issues.
never had a problem with the stuff done by the germans though not the most modern profiles and range isnt big.
i also once ordered a cam that came with lobe separation about 95* instead of 110*, got a replacement didn't have time to fully check it it but some of the basics checked out ok. another cam by same company was 6 degrees too wide in LSA, they sent a replacement and it was closer but the lift and duration was suddenly different.
also another cam by different company this time, when i measured a cam and basecircle on a couple lobes was different. they sent a replacement and the lift was 0.020" too low
when you find it very often you start to doubt if its actually you but when you use new valvetrain bits, different used bits from the factory and use different heads and they tell you same thing .Also recently i know someone else found the same, cam supposed to be 108LSA, i guess 118 is close enough duration was about 14* too big to ...
i get that sliding foot rockers are hard to do as the rocker ratio varies and what not, but if its too hard dont make them. i think they must use the cheap aftermarket rockers to determine rocker geometry for the profile mapping, but those rockers are often different to the factory stuff so that would explain some of the issues.
never had a problem with the stuff done by the germans though not the most modern profiles and range isnt big.