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roverman
Art Gertz
Winchester, CA.
(3031 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Bla Bla Bla roller cams
Posted by: roverman
Date: February 18, 2020 01:53PM

zzzzzzzzzzzzzzzzzzzz I'm so tired of this


Blown v8
Bryan Phipps

(63 posts)

Registered:
03/10/2013 04:52PM

Main British Car:


Re: Bla Bla Bla roller cams
Posted by: Blown v8
Date: February 20, 2020 11:15AM

After 5k miles
9045300C-E3F6-48EF-AA73-5DE0F8DD90F1.jpeg

Now at piper cams,to be sorted out,and micro polished and re-hardened.
TA roller cam, not as good as they and everyone thinks !


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5911 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Bla Bla Bla roller cams
Posted by: BlownMGB-V8
Date: February 20, 2020 11:29AM

Interesting. What are your lift, duration and spring pressures on that cam? What did TA have to say about it? Seems like information that we need to know.

Also if you don't mind my asking, was that the only lobe affected, and what was the condition of the matching lifter? (was it flat spotted?)

Jim



Edited 1 time(s). Last edit at 02/20/2020 11:43AM by BlownMGB-V8.


Blown v8
Bryan Phipps

(63 posts)

Registered:
03/10/2013 04:52PM

Main British Car:


Re: Bla Bla Bla roller cams
Posted by: Blown v8
Date: February 20, 2020 01:41PM

TA denied everything, lifters cam,springs everything bought from TA
Lifters are really good,couldn’t find anything wrong with them
EDED87B6-9629-40D9-BA5F-AF8CF5C50305.jpeg

I can’t remember spring pressures, but I had to buy a bigger set from summit !

My engine is being refreshed at an engine builders, he found the cam,


MGBV8
Carl Floyd
Kingsport, TN
(3895 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
1979 MGB, Buick 215

authors avatar
Re: Bla Bla Bla roller cams
Posted by: MGBV8
Date: February 20, 2020 03:00PM

Cam not properly hardened?


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5911 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Bla Bla Bla roller cams
Posted by: BlownMGB-V8
Date: February 20, 2020 06:43PM

Well, it's a lot of lift and about twice the valve lash that I'd expect to see, maybe more. That can't be helping. What is most obvious to me from that photo is the appearance of the metal being displaced, mashed, or smeared, indicating ductility, or insufficient hardness for the operating conditions. A Rockwell hardness test of the lobe surface might have given you grounds for a claim against TA or it might not. This can't be good publicity either way. However, as close to the limitations of the system as you are running, only a small increase in spring pressure might do it, especially with the hammering caused by the large valve lash. You might want to double check to make sure your spring pressures aren't too high and then close up that clearance some. Considering where the damaged area begins that's what I would look at first.

Also, I realize that lash spec is probably from TA, but it really looks like a mistake to me.

Jim


roverman
Art Gertz
Winchester, CA.
(3031 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: Bla Bla Bla roller cams
Posted by: roverman
Date: February 20, 2020 07:50PM

Your using TA heads ? What king of rpm ? Solid stainless valves ? Big roller cams sometimes benefit from "glass beading the lobes, to prevent "skipping". .650" is a mother-load of lift. Shure you need that much ? All 8620 billet roller cams "should be case hardened to about .080". Art.



Blown v8
Bryan Phipps

(63 posts)

Registered:
03/10/2013 04:52PM

Main British Car:


Re: Bla Bla Bla roller cams
Posted by: Blown v8
Date: February 21, 2020 01:15AM

Yes TA heads, standard valves the heads came with


88v8
Ivor Duarte
Gloucestershire UK
(758 posts)

Registered:
02/11/2010 04:29AM

Main British Car:
1974 Land Rover Lightweight V8

Re: Bla Bla Bla roller cams
Posted by: 88v8
Date: February 21, 2020 05:03AM

Particles blahblahblah
[www.shopfiltermag.com]


tr8todd
Todd Kishbach

(372 posts)

Registered:
12/04/2009 07:42AM

Main British Car:


Re: Bla Bla Bla roller cams
Posted by: tr8todd
Date: February 21, 2020 07:05AM

I'm going with that cam was destined to fail from the start. Thats crazy lift and that lash is too big. The rover cam is a small diameter cam. The LS cams went with a huge diameter and thats what allows them to get .600 and greater lift and still maintain reliability. No way I would go above .550 unless it was race engine and I planned on tearing it down frequently. Seriously, how much extra hp was gained going with that much more lift, and did you really need that extra couple of ponies?


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5911 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Bla Bla Bla roller cams
Posted by: BlownMGB-V8
Date: February 21, 2020 11:35AM

To be fair about it, Buick engines have been running up to .750" of lift. Mostly those are purely drag engines but that by itself doesn't explain the failure. Neither does "particles". If you look closely it is clear that the metal was not worn off the lobe, it was displaced. Now that being the case it is not obvious that the lobe would have failed even though it seems likely.

Jim


88v8
Ivor Duarte
Gloucestershire UK
(758 posts)

Registered:
02/11/2010 04:29AM

Main British Car:
1974 Land Rover Lightweight V8

Re: Bla Bla Bla roller cams
Posted by: 88v8
Date: February 22, 2020 04:34AM

Ha!
Particles was too oblique.
Was thinking of the particles that are now running around inside the engine, that may go through a standard filter but the Filtermag will capture them.

Wonder whether the cam was bedded in at first startup... 2,000rpm for 30 mins, no stops for adjustment or tinkering.. Yes, some may think that elementary but I don't know whether it's a universally accepted practice.

Ivor


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5911 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Bla Bla Bla roller cams
Posted by: BlownMGB-V8
Date: February 22, 2020 11:00AM

To further cloud the waters, Early lifters from TA were made by Morel. Those have fallen into disfavor and the supplier is now Johnson. The Morel lifters were blamed for a number of failures.

Jim

Morel lifters.jpg
Morel lifters


MGBV8
Carl Floyd
Kingsport, TN
(3895 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
1979 MGB, Buick 215

authors avatar
Re: Bla Bla Bla roller cams
Posted by: MGBV8
Date: February 22, 2020 11:07AM

Ivor,

"Wonder whether the cam was bedded in at first startup... 2,000rpm for 30 mins, no stops for adjustment or tinkering.. Yes, some may think that elementary but I don't know whether it's a universally accepted practice. "

Yes, for flat tappet cams. Is that really a concern for roller cams?


Blown v8
Bryan Phipps

(63 posts)

Registered:
03/10/2013 04:52PM

Main British Car:


Re: Bla Bla Bla roller cams
Posted by: Blown v8
Date: February 22, 2020 11:40AM

The engine was “run in” on a dyno,
The cams back,
It looks like TA sold me the wrong springs !
Stay tuned 😎



BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5911 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Bla Bla Bla roller cams
Posted by: BlownMGB-V8
Date: February 22, 2020 03:51PM

Bryan, could you let us know what the spring specs were (open and seated pressures)? Might help someone else avoid this.

Jim


speedybuick
Rob Franklin

(11 posts)

Registered:
12/20/2009 05:57PM

Main British Car:


Re: Bla Bla Bla roller cams
Posted by: speedybuick
Date: February 22, 2020 06:30PM

you'll find a unicorn and talking frog long before TA ever warranties any kind of cam issue even when it's plainly their fault.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5911 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Bla Bla Bla roller cams
Posted by: BlownMGB-V8
Date: February 22, 2020 09:22PM

To be fair, proving it was actually their fault is a stiff challenge to begin with, especially in an engine built for racing where the builder is pushing all the limits to get maximum power. Probably not a fight worth starting.

Jim


Blown v8
Bryan Phipps

(63 posts)

Registered:
03/10/2013 04:52PM

Main British Car:


Re: Bla Bla Bla roller cams
Posted by: Blown v8
Date: February 23, 2020 01:16PM

The springs are 175psi at install height


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5911 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Bla Bla Bla roller cams
Posted by: BlownMGB-V8
Date: February 24, 2020 10:22AM

Yeah that's getting up there a ways. Can you tell us what they were at full lift?

Jim
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