Crow Cam Issues

General Gemini Chat
Forum for all gemini based chat & questions
tobytj
Long Term Member
Posts: 1881
Joined: Tue Apr 10, 2007 3:46 pm
Location: Brisbane

Crow Cam Issues

Post by tobytj »

Boys and Girls,

You are looking at the No 4 exhaust lobe of a Crow "medium" performance cam with a modest amount of milage.

Image

The pictures don't do justice to the level of wear, the lobe peak is way off centre to where it is supposed to be and there is a 2mm loss of lift over all. The wear is right through the cam with variation in total lift on all exhaust lobes.

I would not call this an agressive profile by any means so the wear is surprising.

If you have one of these cams fitted you might want to check it regularly for wear.
Germinator
Long Term Member
Posts: 5903
Joined: Sun Jul 09, 2006 6:13 pm
Location: Albury/Wodonga
Contact:

Post by Germinator »

Unless there has been a fault in manufacture where the hard facing wasn't correctly done, it's unusual for all lobes to simultaneously suffer premature wear, that usually happens as a result of incorrect cam bedding in process.

A single lobe failing can happen from a faulty billet. I'd be contacting the manufacturer and hopefully they will change it over for you.

Check the contact surfaces of the rockers as well when changing cams.
.

I do not give permission for anyone to reproduce content from my posts.
Reposting any of my forum posts (or substantial parts thereof) breaches the copyright act.
tobytj
Long Term Member
Posts: 1881
Joined: Tue Apr 10, 2007 3:46 pm
Location: Brisbane

Post by tobytj »

A manufacturing fault in the hard facing of the cam was my thought too. Yes there is damage to the leading edge of two exhaust rockers but nowhere near the wear that is on the cam.

It might just be a one - off. I have only ever seen damage like this once before but not on a Gemini. In that case the whole lobe sheared off - it wasn't progressive wear. There is no indication of abnormal wear / lubricant problem elsewhere in the motor which has been fully pulled down.
DOHC_TF
Chatterbox
Posts: 77
Joined: Fri May 27, 2005 1:25 am
Location: Perth

Post by DOHC_TF »

I also had a crow cam do the same thing, was on number 4 cylinder to. When i ran the cam in i took the inner valve springs out and also put a bottle of crane cams cam running in additive and the cam was fine for about 6 months then it started to score and wear away the case hardening to the point where it needed replacing. I always run penrite as i get it for stuff all from work so it was always coated in decent oil as well. I have heard of quite a few crow cams chewing out but more so in V8 with heavier duty valve springs.
User avatar
redzone (coxy)
Long Term Member
Posts: 1659
Joined: Sat Jun 10, 2006 3:22 am
Location: sunshine coast

Post by redzone (coxy) »

i have also had a crow 782510 cam do the same thing, yep, you guessed it, on no 4. and they refused warranty. i dont buy crow anymore.
GARAGE REDZONE sunshine coast ph 07 54433507

1975 TX coupe 4ZD1 efi turbo 10.787 @ 123/128
1977 TC Fashion Pack sedan draw through turbo
1984 TG PF60E dohc Group A racecar
1984 TG Panelvan
2006 Crewman SS 6.0
Germinator
Long Term Member
Posts: 5903
Joined: Sun Jul 09, 2006 6:13 pm
Location: Albury/Wodonga
Contact:

Post by Germinator »

Well, interesting that multiple people all have the same problem. Starts to sound like they may have a bad batch of billets. It's possible their billet has issues in that lobe which can happen. It would be interesting to have four or more people all collectively approach Crow to point out after comparing their problems they were willing to have a metallurgist inspect their dead cams and analyze to see if there is a common reason (manufacturing fault of some type) they have all mysteriously failed in similar fashion. I'm sure if Crow thought the findings could result in supporting legal action, they may just offer to replace or refund. If nothing else, hopefully they would discontinue manufacture of Gemini cams on the remaining stock of their billets.
.

I do not give permission for anyone to reproduce content from my posts.
Reposting any of my forum posts (or substantial parts thereof) breaches the copyright act.
TURGEM
Long Term Member
Posts: 1597
Joined: Tue Jul 25, 2006 11:09 pm
Location: Brisbane:- 1.5bar above you

Post by TURGEM »

ive come across this problem but i a 308 black holden in my wb statesman basically the whoe lobe was worn dow and looked similar to one of the bearings but smaller.

i was a lil shocked too when i looked at the end of it and stamped into it was "CROW"
Thats Right Im a Long Term Member
WASTEGATES - WASTE 8S
IF YOU WANNA FLY, GIVE IT MORE P.S.I 8)
User avatar
redzone (coxy)
Long Term Member
Posts: 1659
Joined: Sat Jun 10, 2006 3:22 am
Location: sunshine coast

Post by redzone (coxy) »

well my cam was made in 1999 so i doubt its just a bad batch, i'd just say they're s*#t. i had mine copied and remade by redlands and never had a problem after that.
GARAGE REDZONE sunshine coast ph 07 54433507

1975 TX coupe 4ZD1 efi turbo 10.787 @ 123/128
1977 TC Fashion Pack sedan draw through turbo
1984 TG PF60E dohc Group A racecar
1984 TG Panelvan
2006 Crewman SS 6.0
tobytj
Long Term Member
Posts: 1881
Joined: Tue Apr 10, 2007 3:46 pm
Location: Brisbane

Post by tobytj »

There is a good chance that the criticism of Crow cams for thier cams falling apart might be a bit unfair.

I was talking to my engine rebuilder about a new cam grind and he made the comment that synthetic oils kill cams. They don't put zinc and also phosporous in modern oils and zinc is evidently critical to prevent cam wear.

So it likely that the previous owner of my engine ran an expensive, high performance, synthetic, cam-killing lubricant.

There are additives that you can buy if you need to run flash oil.
User avatar
redzone (coxy)
Long Term Member
Posts: 1659
Joined: Sat Jun 10, 2006 3:22 am
Location: sunshine coast

Post by redzone (coxy) »

mine didnt run synthetic, it ran penrite, and had the cam bedding in procedure followed properly. also dont believe everything you hear about the supposed low zinc oils, most of that info on the net is relevant to the USA, in australia the formulations are different to due our older vehicle fleet...
GARAGE REDZONE sunshine coast ph 07 54433507

1975 TX coupe 4ZD1 efi turbo 10.787 @ 123/128
1977 TC Fashion Pack sedan draw through turbo
1984 TG PF60E dohc Group A racecar
1984 TG Panelvan
2006 Crewman SS 6.0
User avatar
moley
Long Term Member
Posts: 803
Joined: Fri Apr 02, 2010 11:40 pm
Location: Banjo Country

Re: Crow Cam Issues

Post by moley »

Revitalising an old thread, the machine shop has had quite a few engines come in with massive cam and valve train wear. Running the same brand of oil that a couple of you are speaking of.
I usually use it too, even in my Silverado but im going back to castrol
Coupe rebuild number 6..
viewtopic.php?t=44564
F3ARED
Moderator
Posts: 2705
Joined: Wed Sep 28, 2005 11:55 pm
Location: Melbourne, Victoria

Re: Crow Cam Issues

Post by F3ARED »

Apparently these wear issues have to do with the ZDDP content of oils, or lack of it in modern oils. Most synthetics dont have it unless specifically formulated to have it as an additive. Just stick with a pure mineral oil and you should be fine; HPR30 has it etc.
Previously GeminiCoupe/GeminiRollingShell/SCAR3D/Jonnoisac#nt

78 TD Gemini Sedan - R.I.P
81 TE Gemini Sedan
User avatar
moley
Long Term Member
Posts: 803
Joined: Fri Apr 02, 2010 11:40 pm
Location: Banjo Country

Re: Crow Cam Issues

Post by moley »

Yea, a lot of guys at the track and on other forums have been sending samples to Blackstone labs.
It's unreal the findings
Coupe rebuild number 6..
viewtopic.php?t=44564
User avatar
Javi
Regular
Posts: 115
Joined: Sat Mar 03, 2012 6:01 pm
Location: Victoria Point, Brisbane

Re: Crow Cam Issues

Post by Javi »

This is interesting. I just pulled a crow cam out of my G180Z after finding that a lobe was chowdered to s*#t. Been running mineral oil since I got it off of Coxy maybe 4 years ago.
troyrotor wrote:ozgem classifieds - for all your mowing needs
F3ARED
Moderator
Posts: 2705
Joined: Wed Sep 28, 2005 11:55 pm
Location: Melbourne, Victoria

Re: Crow Cam Issues

Post by F3ARED »

Hey Javi, was that a regrind, welded regrind or billet?
Previously GeminiCoupe/GeminiRollingShell/SCAR3D/Jonnoisac#nt

78 TD Gemini Sedan - R.I.P
81 TE Gemini Sedan
Post Reply