175Bhp The Limit For An 8V?

[rochie 1]

Hi guys.

This is my first thread after buying an 8v 1.9 track day car.

The current engine is a pretty well speced:

 

 

rebuilt 1.9 engine which had the crank polished, standard size.

balanced rods and 1.6 pistons.

twin weber 45s

honed bores and new standard piston rings.

the cylinder head had its ports smoothed out and valves all relapped.

new piper hot hatch race cam 292 deg

new cam belt and tensioner.

new engine mounts, rear one solid alloy.

flywheel was lightened, new ap borg and beck clutch.

1600 gearbox

The car was put on a rolling road and made 150bhp at the wheels so circa 175 at the fly.

Is this about the limit for a fast road/tack car or is there any further tuning to extract a bit more power?

I have thought of throttle bodies of course but cant really justify the price as I like the webers anyway.

Further cylinder head work?

Many thanks in advance

[rallyeash 155]

Could get a fair bit more power but it's going to be expensive. Or 16v it and have that power out of the box with better torque potential soon.

 

Certainly not the limit power wise for a track car. My 205 Rallye is 230hp on a na 16v engine and could handle another 40hp, Shame my wallet can't though!

[dcc 855]

no thats not the limit for an 8v.

[GLPoomobile 958]

Without meaning to sound harsh, if you can't justify the cost of ITBs, then you have pretty much reached the limit on your 8v, as your wallet is now the limiting factor (or to put that another way, there's not really any cheap modifications that are going to get you any further). Costs will pretty much increase exponentially as you try to increase power. 175bhp isn't the limit for the 8v, but you are pretty high on the scale already so you are <probably> looking at some pretty serious work to go further.

 

You could go for an iron block and up the displacement with some carefully chosen parts. It'll obvioulsy change the character of the car, but you'll hopefully get a chunk more torque.

 

I suppose there might be some relatively cheap things you could do - like perhaps lighter pulleys and replacing the water pump with an electric pump to reduce rotational mass. You don;t mention if you've used a vernier cam pulley, so if not fitted already, using one might help set it up a little better. Perhaps see if there's anything you can do airflow wise (are you getting a good cold air feed to the carbs and are the filters flowing adequately?). What about the exhaust side? A custom manifold tuned to your specs might bring some benefit.

Edited June 5, 2013 by GLPoomobile

[DamirGTI 342]

Guy Croft made an XU 1.6 8v ported head/engine , which was pulling out over 170Hp ...

 

The engine spes. where - 1.6 bottom end , Jenvey/DTA , piper camshaft , lightened balanced bottom end ...

 

So yes , i can go over the 170Hp .. strange thing is that the head gains inlet port flow massively when an deflector is positioned at an port floor .

 

 

D

Edited June 5, 2013 by DamirGTI

[petert 586]

If it hasn't got big valves & 3 angle seats and flowed then your head is still a limiting factor. Also, you need to rev it to make hp, so that means double valve springs and 320 deg cam. Ceramic coated 4-1 exhaust? Forged pistons at 12:1 would also improve things. I think I just spent some serious money for you.

[welshpug 1,657]

a pretty mild 16v build would breach the 200 mark.

[pug_ham 244 3 Cars]

Miles will now more about this but I'm sure if you are willing to spend the money on an absolute spec 8v you can see 220bhp+ but it's not cheap to find.

 

g

[allanallen 528 2 Cars]

It may open up a can of worms but isn't Baz selling a Mass 1800 8v with north of 210bhp? Probably a decent buy if you're serious about wanky 8 valvers?

[welshpug 1,657]

indeed, its a 210-220 MASS racing 1.8.

 

https://www.facebook.com/photo.php?fbid=355276767891044&set=pb.316390568446331.-2207520000.1370461712.&type=3&src=https%3A%2F%2Ffbcdn-sphotos-f-a.akamaihd.net%2Fhphotos-ak-ash4%2F340907_355276767891044_1901886404_o.jpg&smallsrc=https%3A%2F%2Ffbcdn-sphotos-f-a.akamaihd.net%2Fhphotos-ak-ash3%2F578394_355276767891044_1901886404_n.jpg&size=2048%2C1529&source=timeline_photo_stream

[Miles 331 1 Cars]

That sounds low for the spec, I have done a couple of 8v's with Bodies and 275 Piper cams with mild head work which where 175bhp keeping the budget within reason, yes you can go allot further but expect rebuilds etc

[White Pugs 6]

blah, blah, blah 8v hate etc

Each to their own ;-)

[allanallen 528 2 Cars]

 

Each to their own ;-)

???? It's just a facade I keep up, I'm actually quite fond of the 8 valve motor in my rally car. Just don't tell anyone ????

Edited June 6, 2013 by allanallen

[TT205 42]

^^ LOL

[rochie 1]

Thanks for the great response guys!

 

GLPoomobile: Don't worry about sounding harsh of course the wallet is the main limiting factor. I should have said the limit without spending mega bucks, it's already got a vernier although the carbs could do with another slight fettle.

 

Petert: I think you are right that the head is the limiting factor with standard valves, so that may be the most beneficial improvement. I don't really want to get any hotter a cam as it's already pretty hot for a fast road car. It already has double valve springs.

 

Rallyeash: Thanks for the advice, not really interested in 16v at the mo as I like the simplicity and classic aspect of an 8v.

 

Miles: Does 175 really sound low if anything I thought it sounded a bit optimistic. Not sure on the rolling road it was done at so will have to check.

 

Thanks for all the input guys, I think to sum up without going for bodies, the best option would be; head work, re-jetting of carbs and possibly some exhaust work.

[ORB 227 1 Cars]

To get to the next level you really need to be fitting a stoked crank and pedal clutch

[rallyeash 155]

A stoked crank? Must be pretty chuffed?.....

[GLPoomobile 958]

To get to the next level you really need to be fitting a stoked crank and pedal clutch

 

THat is a quality post But only works if you understand the "in joke", and the OP possibly hasn;t been here long enough, so it'll just come across as misleading

[welshpug 1,657]

 

Rallyeash: Thanks for the advice, not really interested in 16v at the mo as I like the simplicity and classic aspect of an 8v.

.

Unless you have an early 205, an mi16 will be just as old, just as simple

[rochie 1]

THat is a quality post But only works if you understand the "in joke", and the OP possibly hasn;t been here long enough, so it'll just come across as misleading

 

Damn being a newbie! Something to do with a Ozzy making stroked cranks?

Edited June 6, 2013 by rochie

[rochie 1]

Unless you have an early 205, an mi16 will be just as old, just as simple

 

True! I'm sure there will be room for a tuned mi16 in the future.... but for now I like being a bit different with a tuned 8v

[Batfink 201]

you are at the limit of a road driven trackday car. Unless its a race car its largely pointless to take it further. You will spend a lot of money and will end up with a highly strung race engine. Sounds good until you factor in service life and maintenance. If you want to get more power then ditch the 8v.

16v Peugeot engines will be massively quicker.

I wouldnt spend £8-10k building a 230bhp 8v engine when I could buy a honda engine and gearbox running the same power for £2k....

Edited June 6, 2013 by Batfink

[welshpug 1,657]

I wouldnt spend £8-10k building a 230bhp 8v engine when I could buy a honda engine and gearbox running the same power for £2k....

 

And spend £3k making it fit...

[Batfink 201]

hardly...I reckon I will have it all done for less than a grand including custom driveshafts.

Edited June 6, 2013 by Batfink

[calvinhorse 870]

I saw a small hatchback that had been fitted with a Honda engine, bloke only wanted £500 for it..

Think it was called a civic