Phase 2 - 998cc build turbocharged
Turbo Mini Forums

Hi guys would an Avonbar Phase 2 cam suit a turbocharged 998cc 8.3CR ? Also what kind of lift does this cam have ?

Thanks

I tried one and it was terrible, boost threshold rose and the power was very peaky.

I use the MG metro cam (Kent KC500), I have over 180bhp, so it's not a restriction.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

Thanks Wil, I will go for the Kent500 and save up some money for other stuff.

By the way, from the specs how should you know if a camshaft is good for a turbocharged Mini or not. I thought that it needs to have small overlap and large exhaust duration with high lift on both the inlet and outlet lobes. Or it isn't just that ? Yesterday I compiled a little info on possible choice of cams and compared them in the Excel sheet attached.

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You missed the kent MD274.

Like a mini Ph2 for 998s.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Yeah actually I knew about it Paul but I read somewhere on TM that it is not so good due to its overlap. I think for my build I'm going to resort to the Kent 500, but still not sure on the benefits of the Kent 266, the METBP255, the Phase 2 and the Minispares Camshaft Turbo Special over it. Any help ?

On the contrary, the MD274 has a high LSA which is ideal for turbo. Both the Ph2 and the MD274 have 112 degrees.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

The phase 2 seems to have very long exhaust duration which I think helps the turbo keep on spooling. On the other hand it has a very large overlap. With the Kent 500 I think I will be losing both the duration on the inlet and exhaust. On the other hand the Minispares Turbo Special and the METBP255 seems to be a compromise between the two.

However this is my first camshaft replacement so I'm not so knowledgabe on the matter.

Does high LSA mean small overlap Paul ?

LSA means Lobe Separation Angle. A high LSA means lower overlap.

There is a post titled "Lobe Separation Angle". Lots of missing graphs but I can PM you them as Pdfs.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Yep, if you can I appreciate it. Currently I'm doing a lot of theoretical analysis before I start buying the stuff.

I've been having problems with my photo hosting, but now sorted so i'll post them here:

Edited by Paul S on 16th Oct, 2016.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

For what engine displacement and CR are these Paul ?

1020cc and 9:1, 0.8 bar boost.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Thanks a lot Paul. So it seems that the 274 only lacks the lift of the Phase 2. However this week I emailed Kent and asked them what they recommend for a 998cc turbo and they actually said that the 500 is the best candidate. I'm quite confused. However I think that the camshaft selection also depends a lot on the specific engine specs, doesn't it ?

Does anyone have an idea of the quality of the Mega pistons from Minispares ? They are much cheaper than the Omegas. Any experience ?

They've been discussed quite a lot on here over the years. I think the general consensus would be to pay the extra and go for the Omegas.

Phil.

WWW.TURBO-MINI.COM

Hmm I will be a little bit limited on budget however. But lets see how things go.

My other concern at the moment is the crankshaft. I have at my disposal a 1275 A+ block and a 998cc block. I was thinking the other day if I should fit a short stroke crankshaft into one of these blocks, however I would need to stick below the 1140cc, as I don't want to end up in a higher category with the 1.4x multiplier (turbocharged).

My concern however is the fitment. I read that Paul had a hard time with machining the thrust washers, so that might be an issue. But what if I use the 1275cc block ? Or maybe I buy an 850cc block and overbore accordingly ?

small bore cranks wont fit 1275 or visaversa,

998 and 850 swap is also a pain,

So if I swap the 850 crank in the 998cc block, what would need fitment ? I only know of the thrust bearings yet

think thats it, apart from skim a load off the top to get the piston flush.

Yep. Anyone machines these type of thrust bearings ?

nope, and thats why its an issue, it's be a custom job,

But I think it shouldn't be sn issue if we design it in inventor and send it to be machined on a CNC.