1.8 power

[p.mole1]

Hi Paul YHM

[p.mole1]

Not impressed got an email from Radtec stating the radiator would be sent out on Monday (last Monday) rang this morning asking for a tracking number and they can't find one!. Then they tell me its gone out in the van today?. My Mot runs out next week b*****  and I had to pay postage to return it. What ever happened to good service, if this one leaks I'll blow a gasket!

[revilla]

if this one leaks I'll blow a gasket!

Better keep an eye on coolant levels then  

[p.mole1]

Radiator arrived and it seems leak free!

[p.mole1]

Merlin have replaced the Accusump pressure switch, good service. I just need to incorporate the Apollo tank and get an MOT 

[p.mole1]

Been out for a proper run in the car and seems to be performing well,the new radiator is doing a much better job. When I was running the car with the standard head and Super Sport cams it seemed asthmatic and ran out puff before 6000 revs, now it really gets  going at 5000rpm and is still going when I hit the rev limiter at 7500. The gearing is so much better with the 3.62 diff.  I have it booked in for a rolling road setup on the 3/5 lets see if i can break 175 bhp barrier, possibly a tad optimistic.

[p.mole1]

Off to Gemzoe tomorrow, lets hope I don't need a bucket to bring the engine back in. I'm hoping to hit the magic 100 per litre however I think this will probably be hugely optimistic, I would think to get that sort of power out of a K series would require revs above 8000 rpm. We will see, I'm banking on around 160/170 at around 7000 rpm  

[revilla]

Good luck. Show us yer curves!

[p.mole1]

Well I was wrong, 167 bhp@ wheels! I wasn't expecting anything like that. That must be getting close to around 200 at the crank.What I thought was a bit of clutch slip on the road turns out to be the tyres loosing traction. Maximum power comes in at 6800 then starts to tail off at 7000 which is ideal as I'm only running VVC 160 pistons. The only problem was the injectors were reaching maximum capacity so there is probably more power available, but thats more than enough

[revilla]

Fantastic! Well done.

[Paul Mason]

Great news Phil! Same "problem" as me re injectors topping Ng out when I visited the rolling road, but like you say, it's more than enough as is.

[Nick Bassett]

Excellent! 

[StevehS3]

That’s great news. As an aside, I have often wondered where the circa. 30hp is lost between the engine and the wheels. I assume it is lost as heat and sound but it does seem an awful lot. Would better lubrication/oils help (if they exist)?

[Jonathan Kay]

Yes, mostly heat. Every gear pair, bearing, joint etc has its own inefficiency.

Would better lubrication/oils help (if they exist)?

Yes, from that specific aspect. But that has to be set against capital cost, running cost, service life etc.

...

What's the state of the art in motor racing in cars that are roughly like ordinary cars but where those other factors might be less important?

Jonathan

[StevehS3]

Makes sense JK, heat and noise in the tyres too.

[Jonathan Kay]

Oh yes!

The energy lost in sound is very small, and I'd guess negligible in this setting. (And ends up as heat, although it's at a distance.)

Jonathan

[PROBE2]

Hi Phil

I see you are running 285H cams, which I understood make best power at c7500rpm? have you intentionally set rpm low to protect pistons or once injectors changed you will extend rev range?

look good numbers at 7000rpm.

Cheers

Paul

 

 

[p.mole1]

Hi Paul,

I think the figures are just a rough guide, it depends on many factors, ram pipe length, porting, valve size, engine capacity, cam timing etc. I timed my cams as recommend by Piper and if the power was peaking at 7500 my intention was to advance the timing to pull the power down a bit lower. As it happened the power curve was ideal and it was still making usable power at 7500, but i have limited the engine to 7200. You could probably produce peak power higher up by retarding the timing a bit and using shorter ram pipes. Dave did state that my injectors were flat out however I was happy with the results. If you are going to build a similar engine I would use larger injectors. I'm not sure if larger injectors would extend the rev range, but I'm not an expert and there are many variables, it's a very complex science. 

I was astounded with the results and am impressed with the cams they have produced a really nice power and torque curve. 

[p.mole1]

Hi Steve,

A petrol combustion engine is woefully inefficient around 25% of what is used ends up at the crank.

What is left has to make it's way through a gearbox filled with viscous oil, a prop shaft then into a diff filled with more viscous oil, the though CV joints, wheel bearings, discs with pads that rub and finally through tyres. The bhp lost through transmission loss is turned into heat. Do a track day then feel how hot the gearbox and and diff are!

Better oil would be help, thinner oils could release more power but may not be able to protect the gears.

A test was done on motorcycle engines with a reduction in oil viscosity and larger power out puts were the result but probably at the expense of wear, not a problem on a race bike 

 

[StevehS3]

Thank you for taking the time to explain. Interesting. It is nice to learn something new each day. 

[oilyhands]

Further on losses, the major loss on a rolling road is through the tyres which are subjected to unnatural compression via the relatively small diameter rollers.

oily

[D Jones]

p.mole,

fantastic information, you have completed the process that I have started, with results that I would be very happy with.

Could you list out the changes you made to the stock engine as they appear to be extensive and I would like to make sure I have allowed sufficient funds!

I currently have a vvc head which I am flowing, Piper vvc blanking kit, Piper verniers, I need to purchase the Piper (285H) vvc cam kit which removes the vvc mechanism.

I will also go for the hydraulic cam version, but would appreciate advice from anyone with greater knowledge and my logic is that I only need the car for fast road use.

[p.mole1]

Hi, 

sorry for the late response I was at the Lotus 7 day Cadwell,  and I haven’t been near a computer. If you are not intending to any track days I would probably go for a 270 cam. Things can get very expensive quite quickly! I’m using VVC pistons and they are probably at their limit. If you want to use the 285 cams I would budget for stronger pistons, you would also need throttle bodies, a ECU I’m using an Emerald K6 but others are available, probably an exhaust manifold would be a good idea. You can use a VCC inlet manifold but I think it can cause low speed running issues. Also if you are using a 5 speed box you will sacrificing a lot of low speed engine power. My first engine with the std head and SS cams made a superb road engine loads of low down power it ran out at about 6000 rpm. It felt quicker on the road in every day driving and made more power up to 5000rpm but was pants on the track. My current engine makes much less power up to 5000rpm then it really gets going. Dave Andrew is the expert have a look at his K series site. If you are not going to do track days I would try a 270 cam or something similar, this would not need throttle bodies, maybe even standard pistons would be ok if the revs are not too high, you would probably be ok with the standard exhaust manifold as I don’t think it is so critical with a shorter duration cam. You will need injectors the VVC ones should be fine with the 270 cam , I have a set if you need them and an ECU. Don’t get me wrong the 285 cams are awesome and the cars performance at Cadwell was staggering compared to what I had but it’s not so good on the road and needs dropping gears to overtake. You don’t get something for nothing! I’m typing this at work on my phone so it will full of mistakes

[Richard Price]

I would not rule out Piper 633 cams. They are better all round than 270's and work well enough on a plenum.

Or Supersport cams that are somewhere in between 270's and 633's.