new cam for blown chim plus other bits

[Engineer1949]

got the orange chim back for a new cam and followers got the front off and some of the top should have that off later today.


john

IMG_0017 by Brundall Motorsport, on Flickr

IMG_0019 by Brundall Motorsport, on Flickr

[phazed]

What is the reasoning for the new cam John?

[BoostedChim]

What's the cam John? I use a MC1 in mine and it seems to work well. I've always fancied trying the Real Steel forced induction cam though,it has more lobe separation.

[450Nick]

I went for the TVR Power Kent885 (Taraka Cam) it gives much more top end than the MC1 though loses some midrange punch - much longer rev range though and more progressive.

[Engineer1949]

not wanting to rock the boat so to speak its getting another standard cam works well enough no point pushing the engine any further 90% increase is well enough, bit of a surprise when i lifted the plenum three of the trumpets where out of there sockets and one of the ally bells was off the tube must have been making a difference but one wonders if they are really needed at all on a blown engine seems to me might lose some mid range torque without, i have also machined the blower drive pulley to be the same as my latest model loses a fair amount of weight.


john

Edited by Engineer1949 on Thursday 5th May 18:16

[SILICONEKID345HP]

Im wondering if you have been Tango'd :

Edited by SILICONEKID345HP on Thursday 5th May 21:23

[Hoofa]

John I fitted Jools blended base, well worth fitting it as did a back to back on a dyno , when you say standard cam which one are you going for ?. V8 Dev one or a tvr power one ?

[Engineer1949]

tvr power cam set

[Hoofa]

So that will be the 855 cam what did you have in the car originally ? Same cam ?

[carsy]

For a 4ltr doesn't Dom use a Kent 218.

[Engineer1949]

not sure will check when i get it from nick


john

[Engineer1949]

got the rest of the engine apart think i caught it just in time 30thou variation in lobe height and no bad followers chain very loose,


john

IMG_0035 by Brundall Motorsport, on Flickr

IMG_0036 by Brundall Motorsport, on Flickr

[phazed]

The car hasn't done many miles has it John.

[Engineer1949]

its done around 4500 miles since rebuild but the cam is going off and after what happened to mat with his newly built race engine didnt want any disasters so thought it best to check, followers are good chain is not and cam has up to 30thou lobe height difference all ready problem is i guess will the new cam be any longer lasting but cant leave as is.


john

[ChimpOnGas]

Engineer1949 said:

its done around 4500 miles since rebuild but the cam is going off and after what happened to mat with his newly built race engine didnt want any disasters so thought it best to check, followers are good chain is not and cam has up to 30thou lobe height difference all ready problem is i guess will the new cam be any longer lasting but cant leave as is.


john

If you don't mind me asking John...

"Why such a short cam life?"

I'm sure your next objective will be to fully understand the issue before the new cam goes in so the experience isn't replicated.

Your findings and answer to the above question will be of great interest to us all.

[Hoofa]

I would like to understand too why only after 4500 miles, hence the question on who's cam it is

[Engineer1949]

the cam i fitted was supplied by a well known tvr shop same supplier mat used with his failed cam, i have been looking at it in more depth today and the wear pattern on the lobes is very uneven some have only a small contact area particularly noticeable on the lift side as you would expect, top of the lobes are reasonable in so much as most have a shiny surface most of the way across but that i feel is down to the wear as the lobes are all at differing heights all be it only 30 odd thou between them i will scrutinise the new offering when i get it tomorrow dont want a repeat but where else to go to get hopefully a strong well engineered cam etc,i will also check the case hardening when i get the old cam down to my old mate franks as he has all the relevant kit for such an undertaking.


john

Edited by Engineer1949 on Wednesday 11th May 17:32

[ChimpOnGas]

Engineer1949 said:

The lobes are all at differing heights all be it only 30 odd thou between them i will scrutinise the new offering when i get it tomorrow dont want a repeat... but where else to go to get hopefully a strong well engineered cam?

Well mine came from V8 Developments, obviously they dont grid cams themselves but what I can tell you is my Stealth came in a nice Piper Cams box. I can also tell you after a very recent inspection it's doing just fine four years after Rob Robertson fitted it. The timing gear was all JP from Australia, supplied and fitted by Rob at the same time as the cam, both chain and sprockets are doing just fine after thousands of miles as are the V8 Developments supplied followers .

The two big players in the UK are Kent Cams and Piper Cams but even these guys are really just grind houses, they will be getting their blanks from a foundry, and who knows where that is? Saying that I'd be surprised if long standing companies Kent & Piper weren't super strict when specifying the metallurgy and hardening process of what they buy in, it's their name on the box so their reputation at stake after all.

But Kent and Piper (and their appointed re-sellers) aren't the only sources of Rover V8 cams, when cam time comes around again for me I will be looking seriously at the latest hydraulic roller cam kits, there are a number of vendors offering this kit like The Wedge Shop in the US and Triumph Rover Spares in Australia.

http://www.thewedgeshopstore.com/products/Roller-C...

http://www.triumphroverspares.com.au/page.asp?pare...


But I believe the original source is TA Performance of Scottsdale Arizona:

http://taperformance.com/products.asp?cat=456

And if you buy from them you can specify your own forced induction grind for just another $189.00, personally that would be the way I'd go.

Edited by ChimpOnGas on Wednesday 11th May 18:20

[Hoofa]

I have explored the roller cam option , far too much money and too many unknowns to consider any real gain, the wedge shop was ok but buying something at a distance that may or may not work is too risky

U.K cam companies like piper and Kent for some reason won't entertain roller cams,

Plus I asked power if they would consider doing one but people won't pay the money when they can get a standard cam for not a lot , I guess for them is its not worth the development costs

I am not saying it's impossible but it will cost and for what increase ?. Just stick a blower on it job done

Edited by Hoofa on Wednesday 11th May 20:15

[ChimpOnGas]

Hoofa said:

I have explored the roller cam option , far too much money and too many unknowns to consider any real gain, the wedge shop was ok but buying something at a distance that may or may not work is too risky

U.K cam companies like piper and Kent for some reason won't entertain roller cams,

Plus I asked power if they would consider doing one but people won't pay the money when they can get a standard cam for not a lot , I guess for them is it worth the development

I am not saying it's impossible but it will cost and for what increase ?. Just stick a blower on it job done

Edited by Hoofa on Wednesday 11th May 19:39

Good response, you've clearly looked into all this a lot deeper than me.

Thanks Nigel, that's a chunk of money you've save me there