17 replies to this topic

[Craig89]

Does anybody have any info on the above cam? From my research I think its made by piper. I have been offered one for a 1275 build but its pretty useless without cam details.

Thanks, Craig

[Pigeonto]

I'm fairly sure they called them HR 270, HR 285 etc before changing name to BP prefix and that you can use the current data from Piper, 31/65 and 65/31 to save you the trouble. I had one in a 1275 and it was very effective..... Edit..385 thou lift with standard rockers both valves..Power band 1500 to 6500. They claim 10 hp gain over standard cam

Edited by Pigeonto, 22 October 2012 - 09:55 PM.

[Cooperman]

I'm always amused at the way some cam vendors claim xx bhp increase over standard cam. However, they never seem to point out that you can only get that increase with a better flowing head and improved induction and exhaust systems. The key to power in the A-series is a better head.

[jaydee]

Well said. You can fit whatever cam you want, if the engine does not breathe, you wont have any gain.

[Craig89]

Thanks for the info pigeonto. The probable reason for the maufactures not mentioning the need for further mods, in order to gain the most from there cams is because it would put certain people off i.e. the not very well educated people/people with disposable income, who think that a cam is just a bolt on 10hp gain modification. Then its not until after they have spent their money that they realise more work is actually required. That's the only reason I can think of any way.

Thanks again for the details

Craig

[jaydee]

Well Craig, what some usually dont claim is the fact that to make the combo work at its best you have to make some calculations and pick a cam and cylinder head with lift, valve size and CR that work together, then the porting and the chamber shape give the extra performace improving breathing further more.
While kent cams give a full list of cam specs so you can make your own engine spec, some manifacturers doesnt quote any of their figures so you have to call them asking what works with their cams and what not, in a short, they'll put an engine spec for you.

[Cooperman]

Kent cams do a really good graph for their cams which shows where the power and torque curves are and that is why I almost always use the Kent product.
Some people come on here and ask about cams like the 286 or 296, but if they actually looked at the cam graphs they would see how the cam delivers its power. Take, say, a 286. The graph shows that its best power is between about 5500 rpm and 6700 rpm, so if you intend using one of those your engine must be capable of pulling those revs in all the gears and sustaining them without blowing up. It is assumed that matching head, manifolds and carb(s) are also necessary together with a different advance curve from the dizzy.
Jaydee is absolutely right when he says that it's all a bit more technical than adding a cam to get more power. The final drive ratio and gear ratios are also factors in cam selection as if the ratios don't allow the engine to be kept within the best rev range for the cam the car will actually lose performance and simply use more petrol.

[Craig89]

I totally agree with everything said above. I'm looking for a cam for an engine I'm building, hense why I wanted the specs. I wasn't hoping for a "race cam" that adds 3000bhp :)

[Cooperman]

Piper cams have a good reputation although I've never worked using them because I like the technical support available from Kent. A Piper 270 should be similar to a Kent 266 which is, quite simply, a superb road cam for a Mini and very good with a standard gear ratio set. If you can get the cam profile details and compare it with the Kent 266 it will give you confirmation, but first reaction would be to go for it as it won't be a bad cam and if the 270 refers to the valve overlap timing it should be fine.

[Cooperman]

and if the 270 refers to the valve overlap timing it should be fine.

LOL if it did the engine wouldn't even run...............the numbers in cam spec's usually are quoted inlet duration, not overlap........

Typo, meant duration, sorry for the error.

[Craig89]

I have had this cam in a block today and had a crack at measuring the cam profile. The results I got are as follows:

Inlet:
Opens 39 BTDC
Closes: 61 ABDC
Max lift: 277.5
Duration: 280
LCA: 101

Exhaust:
Opens: 76 BBDC
Closes: 23 ATDC
Max lift: 278.5
Duration: 279
LCA: 116.5

Overlap lift wasn't measured as I only have 1 DTI.

LSA: 108.75

Can anyone that has knowledge of cam profiles tell me if this sounds plausible (so I know I measured/calculated correctly). Also if cam behaviour can be estimated that would be nice.

Cheers, Craig

[Captain Mainwaring]

Quite plausible - quite a high speed cam by the looks of it.

[Earwax]

Hi Craig89, i can't add any more to the above- aligned wisdom, but if you don't mind, i will add further to the question of unknown cams.

 

 

Given that quite a bit of research and development goes into the 'perfect profile' cam, , are there any royalties or fail safes for stopping 'pirating' of profiles

 

I know some profiles are locked under licence (race developed) and needs the cam maker to get permission to regrind to that setting, i also know of sharing profiles under licence (eg Calver markets the Russell engineering cams in Uk) but for the common everyday cam what occurs?

[Captain Mainwaring]

Hi Craig89, i can't add any more to the above- aligned wisdom, but if you don't mind, i will add further to the question of unknown cams.

 

 

Given that quite a bit of research and development goes into the 'perfect profile' cam, , are there any royalties or fail safes for stopping 'pirating' of profiles

 

I know some profiles are locked under licence (race developed) and needs the cam maker to get permission to regrind to that setting, i also know of sharing profiles under licence (eg Calver markets the Russell engineering cams in Uk) but for the common everyday cam what occurs?

 

It's down to the individual supplier. 

I company I work with have an agreement that a parts supplier won't produce a particular item outside of it's license with us...great, all well and good, but that doesn't mean someone else can't copy it.

 

A cam is a cam, someone only has to change the lift a tiny bit, or the duration, and it becomes a different beast.

Any company selling to the general public will be aware of that by now - and so I am informed on this very forum, it's alright to copy/pirate, you get what you pay for and ultimately the customer has a free choice.

Personally I think it stinks, having something copied that you've worked hard to develop, especially as a smaller supplier who can't take on copyright law suits.

[carbon]

The timings and lift I found for the Piper HR270 are :

inlet 22/62, lift 0.284

exhaust 64/28, lift 0.284

Lobe displacement angle 109 degrees

 

Can't recall where these came from, so can't vouch for accuracy. There are slightly different timings for the HR270/2 and BP270 Piper cams.

 

At one point I seem to recall the Piper HR270 was being advertised as having asymmetric profiles, with faster opening.