What sort of BHP from this little lot ????

[tay]

I'm having my car tuned tommorow on the rolling road by a company specialising in twin 40's etc and would like to know what sort of power I can expect realistically from my engine. The spec is as follows :

*C16SV engine fully reconditioned bout 6 mth ago
*Head ported, polished & skimmed with 3 angle valve seats
*Weber Twin 40 DCOE's with inlet manifold ports enlarged and polished to match carburettor and head ports
* Piper 285 Degree Fast Road/Rally Cam with Vernier Pulley
* Weber Alpha 3-D ignition Management replacing Dizzy
* PMC 4 - 1 Exhaust Manifold leading to full Powerflow stainless exhaust

Anyone know what sort of power I should expect to get ? I'm hoping in the region of 130 - 140bhp if they get it tuned properly ?

Cheers

Tay

[Chip_RB]

That power estimate sounds about right to be honest, but obviously its going to depends on the condition of the bottom end etc.

Chip

[tay]

I've never really had a look at the bottom end to be honest, its been re-conditioned though so it shud be ok. what sort of things should i look out for ?

[Chip_RB]

The only thing on the bottom end that is going to effect power really is ring seal.
Obviously if bearings are knackered you could end up with an engine thats scrap if they fail but they wont really effect power output until they actually allow so much movement of the rod that it breaks or whatever.

If its been recon-ed both the rings and bearings should have been done, but that doesnt mean they actaully were of course!

Hope you have ARP rob and head bolts, cause you will be looking at 7K+ rpm so you will need them really.

[MC]

Nobody ever asks the correct questions!

What size chokes have you got? These will determine the bhp and torque. If you are running 30's you'll be between 130 and 140bhp with shed loads of torque. 32's will be 140+ and 34's will be up to around 150bhp with a progressive torque curve.

MC

[Chip_RB]

What use is it asking what chokes he has got on the way into the rollers, surely thats up to the rolling road operator to sort out with you while you are there?


Chip

[MC]

No, you tell the operator what you want to an extent. A decent RR will taylor the car to your request. So if he went in there and said he wanted a peaky engine with 34mm chokes, they would set it up to suit. If he said he wanted loads of torque......

Get what I mean, Webers are a flexible tool, and no one setup or choke size is correct. You have it as you want.

MC

[Chip_RB]

Im aware of that, have had webbers on cars before, its surprising the difference a different size choke can make, but you havent mentioned how much harder it is to get the thing running light at low gas speeds (ie low rpm) on 34's

Personally for a road 1600 i would go for 32's at most and aim for about 140bhp


Chip

[MC]

I'd agree, 32 is about right. I was making a point though that it was difficult to pin point bhp without knowing that vital information.

MC

[Chip_RB]

Even with all that info and strapped onto the rollers any figure is only a guess at best TBH, short of an engine dyno you can never really be sure.

[tay]

right well I'm pissed off now !

Just got the car back from the rolling road and the peak power it made was 104BHP at the flywheel !!!! :evil: :evil: :evil:

I'm really f****d off !!

I'm gonna try and copy the graph onto here to show you boys and see what you think

[tay]

how do i scan the graph onto here ?????

[Aragorn]

what ignition system did u use?

dan was attempting to use the original ignition from the gte engine on his and was getting crap results

maybe swap for an SR dizzy and coilpack?

or failing that the next option would be some kinda mappable ignition system like weber alpha

the only other thing would be cam timing or ignition timing

did they check/reset this?

what was the fuelling like?

[tay]

I've got the Weber 3-D ignition management system on there already. all they done was re-balance the carbs and re-map the ignition. somehow i don't really think they know that much tbh though.

[Aragorn]

u need to find someone who knows how to set up this properly and knows what they are on about

those guys should've known summat was up instantly and given you some possible solutions

check the timing first - it may well be out adn that could be your problem

hrm one thing - u said they balanced the carbs and setup the ignition

did they touch the jets etc in the carb at all?

if its over/underfuelling you'll get crap power and risk damaging the engine too

where did u get the jetting settings from?

[tay]

they done the jetting settings themselves so i don't know what i've got in there, I'm gonna take em out tonight and post them up here. I thought the car was overfuelling cos the spark plugs were black when i took em out. I asked em to check whether the car needed a fuel return plumbed into it cos there isn't one at the mo and they said it didn't need it. Its got a fuel pressure regulator on there and a facet fuel pump as well. I've had the timing checked by the bloke who done my cylinder head cos he runs a performance engine comany, and he said he would like to advance the cam timing by one notch but not before i got the ignition re-mapped, so i'm gonna take it down to him a.s.a.p me thinks !

Anyways heres the link to my rolling road printouts if you're interested see what you think !

http://uk.f1.pg.photos.yahoo.com/jaytay68

[Chip_RB]

There is no point getting the ignition mapped and then altering the cam timing as the ignition would be re-mapping again afterwards.

Make any mechanical changes first, then get it set up.

something is VERY wrong there somewhere though to be only making 104bhp

[tay]

Right well here are my jettings:

Emulsion Tube : F16
Air Corrector : 155
Main Jet : 130
Accelerator Pump Jets : 40
Idle Jet : 50

MC - soes this sound about right ? I will post up the choke sizes tommorow mate

[tay]

Just checked the chokes and they're 30's. Surely even if the jetting aint completely spot on it wouldn't make that much of a massive difference in power would it (like about 30bhp) ??

[Stuart]

go to velos ;)

[tay]

cambridge where's that then mate ?

[Stuart]

velos should be hear youi (i belive)

there is a website that they have so you can contact them (but i cant remember) just search on yahoo for xe tuning/DTA/torque tube etc


as for chokes etc there is a certain 1.6 8V thats running a lightened and balanced bottom end, B+ (or ++) head, kent AST2 cam, T40's 34mm chokes and ashley exhaust (not loud really) that chucks out hell of a lot of power and also very very very useable torque curve.

it pulls like a demon from 30 even in 5th lol

[MC]

Yeah, Tom Lunn's had 34mm chokes and went below 15secs at the Pod. There is torque in abundance with the 1600 on 40's.

Your graph is a typical 30mm plot. You have more instant torque than bhp. The reason you are down on bhp is that your Air correction jets are to rich. You need around 180 - 190. You're running far to rich at the top end. The mains are about right for 32mm chokes, and I'd say you need a 45 idle jet.

You need to politely ask for your money back!

Whereabouts do you live?

MC

[CP]

My 1.6 (150hp) on T40's was running:

30 mm Chokes
Mains = 4cylinders * 30 mm chokes = 120
Air correction 190
Acclerator 40
idles 45f8
Emulsion F11

Your jetting doesnt sound too far out.

Its quite feasible to get this low a reading esp. if you go to a no bullshit low reading r road ( usually the most accurate). Dont panic yet

The 1 thing that I noticed is that although you have had some headwork there's no mention of larger valves. TBH you aint gonna get 130 - 140 true HP out of it without them- I know cos I tried it. I ended up enlarging the ports by 2mm and having Bill Blydenstein put large profiled valves in for me. I think your head may actually be no better than a standard head.
Also your engine is new and only just gone together - you'll never get full power until the heads coked and the bores/rings have bedded in - new engine build can lose you 5 - 10hp straight away!
Also was all the inlet and zorst etc.matched to the head?


Drive it for a few thousand miles - go back to the RR.
It should get stronger and if you take on std GSi etc you should get some idea of how strong it actually is.
Horsepower readings are only a guide- patience is needed- its not possible to just turn top power on like a switch

[Will]

wise words, top advice in the last 2 posts!

good luck! let us know how u get on.

im keen to know the difference between your bottem end and a GTE/GSI nova bottem end or if there is no difference at all etc

:D

[tay]

I've just had a look at Velos and they are a bit of a mission from me cos I live in Surrey near Croydon!

I went out and bought bigger accelerator pump jets (45) and bigger main jets also (135). I tried the bigger accelerator pump jets and it seemed to nearly get rid of the flat spot I had at 2000rpm. Gonna swop em back to the normal one and then try the bigger main jets and see what they do. MC I'll buy some air correctors and see how it drives then. I'm also gonna check the timing cos the place that r/r didn't bother (i though tis was quite important when setting up an engine??). Its got a vernier on it so it wont be too hard to adjust.

I've also noticed that the carburettor place have screwed in all the idle screws as far as they will go - i though they had to be turned out a little bit at least ! It just seems to me that a lot of these so-called performance places don't really know as much as they pretend they do ! :?

[Will]

Velos know theres stuff but there is a place in cambridge at a garage the guy there knows his stuff abt carbs, cp knows the name of the garage if i remember rightly........

[Dan]

velos is a mission but they have proven worthy of the journey for me, takes me 2-3hrs or so to get there but worth it as i have tried all 4 in my area and not had results and advice like i have from them

[tay]

Well the way its going at the moment it does look like i'll be taking a trip down there after all ! I'll probably drive down there first thing and wait around while therre doing it - at least i'll get to see them do the work !

[Stuart]

the garage that will is on about is called wilshers (tend to be an MG place but will play with all carbs)


i thought as you had sutton in yer "location" meant sutton coldfield lol.

[MC]

I used to go to a place on the A127, halfway to Southend, they are Weber experts, and I would trust them. Specify that you want bigger chokes though.

Living in croydon, you must have been to Southend cruise, so you should know the A127. You can actually see it from the road.

MC

[tay]

yeah thats a bit closer ! don't suppose you can remember what they're called by any chance do ya ? Did they do things like sort out timing as well or just solely work on the carbs ?

Cheers

[tay]

Just had to call out the AA to come and have a look at the car cos the following happened .......

Was driving round to the birds house when I had to pull over cos me lighter had gone under me seat somewhere, switched the engine off and when i went to start it again when the engine was warm it wouldn't start. This has been happening ever since it was 'tuned' but would start again after about 30mins. sat there for ages trying to start the engine every 20 mins or so until me battery went flat. called out the AA man who recharged me battery and he couldn;t understand what was wrong either. He took the fuel pipe of the carbs and when i went to start the engine hey presto it started ! anyway to cut a long story short it has turned out the the carbs are massively overfuelling, so I think I will be having 'words' with this f***ing S***e carbs place cos of all things i would've thought thet would've checked the fuelling ! :evil: I even asked when I brought it in if they could check the fuelling and see if they needed to install a fuel return line and they said that the fueling was fine ! I mean I spent ?250 on this so called tune up and am wondering what exactly they did do !!!!

Anyway rant over - for now :twisted:

[Dan]

you shouldnt need a fuel return

[MC]

Your carbs are deffinately over fuelling. 130 main is marginally too big, and the air correction jet is too rich by miles.

Dan is correct though, you shouldn't need a fuel return if the pressure to the carbs is regulated below around 7psi, 3.5 beeing best. Check the floats aren't damaged or missaligned.

I would occaisionally flood my engine and it wouldn't start for ages, unless.....I helld the throttle wide open and turned it over for a while. Its embarraassing though as you get plumes of black smoke when it does fire up.

I could set the engine up for you with correct jetting and chokes, and I'm sure CP would time it. It won't be as accurate as a 'Pukka' rolling road, but it will be 99.9% closer than you are now!

I can't remember the name of the garage I'm affraid.

MC

[tay]

Cheers for the offer MC I might just have to take you up on it. I've gotta take it back to the carb place today for them to have a look at it, cos when i spoke to em they said no way it was overfuelling ! bunch of cowboys :evil:

[Serialkilla]

Which carb place did you take it too Tay?