Longmans 1600 Head Spec

[Mark205T45 0]

What do you all think of this head??

 

205 1600 Head.

Ported and polished

27.3cc Chambers

42.5mm Inlet Valves (+1mm)

Piper 495 cam (timed to std marks)

Valve clearances: Inlet = 0.008" - 0.009" Exhaust = 0.010" - 0.011"

Compresion ratio 11.0 - 1

Omega Forged 83.5mm Pistons

Cometic steel head gasket

Chamber volume of 27.3

 

Unsure how good the cam is what lift etc...anyone know? think its custom...possibly going piper grp a 2 if it will fit

 

Also running on jenvey tb's and omex

 

Bottom end is lightened and balanced and peugeot sport crank

 

Aiming for 180+bhp 1.6 8v rally engine

[Saveit 0]

180 bhp should be possible. Mine has similar specs (also longmans head) and it is going on the rollers tomorrow. Last time - without forged high comp pistons - it made 170 bhp at about 8000 rpm. This was also with a bit too aggressive cam. Should be producing 180 bhp now.

[Mark205T45 0]

180 bhp should be possible. Mine has similar specs (also longmans head) and it is going on the rollers tomorrow. Last time - without forged high comp pistons - it made 170 bhp at about 8000 rpm. This was also with a bit too aggressive cam. Should be producing 180 bhp now.

 

Awesome....yes i hope for 180 minimum trying to get it VERY competitive in the 1600 class in stage rallying (tarmac) probs will go with the grp a cam from piper seems to have a good spec...

 

Will let you all know what it makes....

 

Can someone tell me what the highest powered n/a 1.6 8v is they know of??? and what it took to build it as i would love over 190 bhp

[tony perks 1]

Mark, I think from Memory the 495 piper cam is just a BP300, but on a narrower lobe centre angle 104 degs instead of the normal 106deg.

 

The Grp A2 cam that I used has 308deg duration inlet and exhaust, gives .490" lift, and has .186" lift at tdc, when timed to 104degs, However in the bigger engine we found a wider spread of power Timing it at equal lift at tdc, but found that if I missed a gear then the exhaust valve would just kiss the piston!!

 

Piper recon this cam to give a power band of 3000-7600 but in reality with the longer stroke engine the power came in at about 2800 and would tail off at around 8000, but would hang on to 8500.

Edited October 10, 2009 by tony perks

[Saveit 0]

So got mine on the rollers. And raced it yesterday and also today. Unfortunately it only made 160 bhp at 7700 rpm and 160nm at about 5600 rpm. The power is only really there at about 5000 rpm until the rev limit at 7800 rpm. At 3000 there is no power at all. 4000 is okay but not really fast. At over 5000 it pulls very nicely. We tried pushing it over 8000 rpm but sadly the performance just dropped.

 

The engine has high comp pistons and the piper 1600 race camshaft at 308* (think its called BP320?), longmans top (made 225 bhp on the former 1.9 engine it came from), jenvey 45mm throttle bodies, 4-1 exhaust manifold. Really cant see why it wont make over 160 bhp... And i really dont understand why the performance drops at about 8000 rpm.

[Batfink 201]

you probably cannot get enough air in after 8000rpm.

[Saveit 0]

you probably cannot get enough air in after 8000rpm.

 

Cant see what should cause this? 45mm TB's with 4 inch air horns should be more than enough. There is no filter on either.

 

My only bet would be the exhaust. Would think a 4-2-1 manifold would be better wouldnt it? And i dont know if the 2" exhaust from the manifold and backwards is enough.

[Batfink 201]

2" exhaust system is good up to around 200bhp usually.

[Saveit 0]

Could it be the 4 inch air horns reducing the top end power? And what do you think about the 4-1 exhaust?

[boombang 2]

There is no filter on either.

 

sure fire way to kill an engine!

 

My only bet would be the exhaust. Would think a 4-2-1 manifold would be better wouldnt it? And i dont know if the 2" exhaust from the manifold and backwards is enough.

 

A particular 4-2-1 manifold may be better for your application, but by no means can you assume any 4-2-1 manifold will be. Seen a few with terrible pipe joins, very badly made. These could sap power completely.

 

IIRC Sean Mckeown claimed issues with a generic bottom of the range manifold capping power. This may or may not really been to do with the manifold but logic says it could have been.

[Saveit 0]

Which is the best exhaust manifold?

[sideways danny 0]

personally I think you're doing well to hit 100bhp per litre from an 8 valve. You're most likely on a far more realistic dyno than the "225bhp" 1.9 was

[tony perks 1]

personally I think you're doing well to hit 100bhp per litre from an 8 valve. You're most likely on a far more realistic dyno than the "225bhp" 1.9 was

 

225BHP from a 1900 is quite possible I have seen 1 at 225 and another at 215 both similar specs, but on very different climatic days, and on the same day and dyno we measured my standard 1.9 205 and my work mates 1.9 and got 124 and 121 bhp respectivly.

 

As for exhaust manifolds I have found the magnex to work very well for me, and use one on all race and rally engines we build now.

Edited October 12, 2009 by tony perks

[Mark205T45 0]

Tony - The 495 in there is coming out its a custom cam....i will be going kent pt27b or piper grp a 2....i hope mine makes abit more then 160 id be happy with 180+ seeing as the work thats gone into it...

 

And as for the best manifold i and people i know with quick 205's always run a maniflow 4 branch

 

I will let you all know what power i make....it wont be on tb's now as im going back on twin 45's as tb's arent worth the money to power gain i will get.

[Saveit 0]

Well if its not on TBs, and judging from my results, i wont think youll be at the 180 bhp mark. More likely the 160 bhp that i am getting...

[tony perks 1]

T B's MAY not make any more power but the extra drivability you WILL get from the fully mapped ingnition curve will be so much better than a load of springs and weights will ever give, and no i dont think you will see more than 160bhp on carbs and a dizzy, at least not with a pt27 any ways, the best 1.6 with a 27 ive seen was 162 fully mapped with bodies, and another on bike carbs made 157, the 1900 will make better use of the 27 every time to make one work i suspect the lobe centre angle needs narrowing by a couple of degrees.

[Mark205T45 0]

Right guys spoke to engine builder today and this is the final decision on the build:

 

Twin 45's running alongside a competition dizzy

Piper 495 cam

And of course the full longmans head big valves etc

Peugeot Sport Crank

Lightened Flywheel

Lightened conrods bronze bushed and treated

ARP Rod Bolts

Competition Bearings

All Elring Gaskets

Cometic Headgasket

CR of 11.1

Omega 83.5mm Forged Pistons

 

Etc Etc

 

We are expecting in the real world 160-165bhp all setup properly (i know the king in weber tuning)

 

But thats good power as in the real world with the gripper diff and a cwp final drive is 4.8 on a BE3 box it will be quick anyway

 

 

This engine is far more superior then the current one and we always have good results when we dont make mistakes or not finish so things are only looking up

[boombang 2]

With the price of a Longmans head and the rest of that engine spec cost, would rather have had throttle bodies and decent management myself. Doesn't make sense to sped £xxxx on those bits and keep it on a dizzy!

[taylorspug 7]

Or at least run ignition only managment so you can map the curve. Wouldnt even be too expensive for an ignition only ECU.

[Saveit 0]

Well on my engine at least we found just about 10nm by playing with the ignition curves. Thats a fair bit. I wouldnt go with a dizzy....

[Galifrey 1]

Well on my engine at least we found just about 10nm by playing with the ignition curves. Thats a fair bit. I wouldnt go with a dizzy....

 

I would agree with all the above, all that money for a head and not running a spark management is false economy to my mind.

[Mark205T45 0]

Only reason i say im not using different ignition is after speaking to a guy who really knows his stuff with carbs and ignition setting he thinks its not worth doing....

 

The cost of the build was 4k but i bought it built and done 5 road running in miles before the car got written off so i paid less then half that....

 

I can always go down the road of tb's and different ignition in the future....but for now id rather get back out rallying...i and alot of others have always had good results using dizzys so....

 

Ok so if i go the megajolt or weber alpha how much is the kit ?? and how is it set up?

Edited October 13, 2009 by Mark205T45

[boombang 2]

Only reason i say im not using different ignition is after speaking to a guy who really knows his stuff with carbs and ignition setting he thinks its not worth doing....

 

Ok so if i go the megajolt or weber alpha how much is the kit ?? and how is it set up?

I would question that they really know what they are doing given current options (note not questioning they know carbs, just sound very out of touch). To think that a mechanical dizzy can compare with a proper mapped ignition system suggest they are stuck in the dark ages!

 

I wouldn't touch either Megajolt or Weber Alpha - a minefield of woes that many have given up on and a system that can only be mapped by very few with no public access to software respectively.

 

You will either need trigger wheel or to run Mi16 style flyweel with CPS, TPS, and a bit of knowledge - then you can get it on.

 

Omex 200 £350

Loom say £50 for breakout loom then make up using standard connectors and new inserts (available from Vehicle Wiring Products etc).

Sensors themselves - pennies or pounds depending on source.

Can go for a coilpack off a 106 xsi or many other cars too, get rid of dizzy completely.

 

Then just needs mapping.

 

Sure not cheap, but I'd say from your setup it'll give a serious amount of power and driveability - in fact you won't be able to get more torque per pound any other method.

[Mark205T45 0]

I think its something im going to look at in the future....its costing me 3k just to get car back running after buying this engine etc...its more important for me to start the championship in january then be buying the ignition system and loosing out on championship points...

 

Deffo going to look into it for the future....

 

This guy admits it wont be AS good but certainly wont be bad running on a dizzy

[stuart 31 3 Cars]

Sounds similar to what I'm doing and having the same dilemna about recurved dizzy vs mapped ignition, from a money point of view anyway.

 

I've roughly worked out that it's either 100 or so for a H&H dizzy or 4 or 5 times that for mapped ignition, including the mapping. I'm still undecided if the gains of going mappable are going to be worth that much more or not.

 

Has anyone tried both on the same (or similar) setup?

 

By the way, who is setting your engine up? I'm taking mine to Mikeanics as I need to get the car on the rollers there anyway for my championship but have heard that he knows 205's very well.