Hillclimb Engine - What To Do First

[wardy18 33 1 Cars]

Need some advice

 

As my pockets arnt endless i need to plan what to do when to the Hillclimb Engine

 

Currently it's a XU9 engine Running Twin 45's, a Rally Catcam, 60 thou head skim, Double valve springs, standard bottom end.

 

So what do i spend the money on first, a BV 8v head or a sorted bottom end

 

If i get the bottom end done thid means i can drop into a more competitive class and also have the confidence of a balanced lightened engine which i can rev the nuts off to the limit of the crank, details are XU7 crank and Sandy worked Rods and Pistons in a XU9 block

 

OR

 

I can get a ported/polished BV head fitted with my Catcam etc etc, but this means i stay in the class im in and have to save for the bottom end, but this is a little cheaper to start with rather than the botom end which would better suit my pocket at this monent in time!!

 

What you reckon would be advantageous to me?!?!

 

Simon

[James_R 3]

Save and do it in one go, wil be cheaper that way.

 

But given the choice bottom end as you have all the other bits to make it work, you won't loose much power and you'll be more competative.

 

Then have some fun and then deicde.

[wardy18 33 1 Cars]

yeh il have to see how dep the pockets can go right now and what prices sandy can give me!!

 

why doesnt money and car parts grow on trees!!!!

[James_R 3]

That's called, not having a girlfriend

[welshpug 1,626]

whatever you get making sure its setup and running well is the most important thing

 

too much emphasis is put on BV heads, Sandy has proven a few times how far the standard valve sized and very light headwork can produce good results.

[VisaGTi16v 1]

Another option would be to move to England and compete in the South/SE where the split is at 2 litre so at least you dont have all the silly turbo nonsense 4wd cars to deal with other than the odd R5

[wardy18 33 1 Cars]

mate i would love to move to the uk but cant ever imagine doing it, there's a big scary wide world out there and my little rock protects me lol but yeh what a dream, id buy a camper van and i would be leavin the mrs behind every weekend and headin to shows and track days and races, endless enjoyment

 

BUT NO

 

i compete on the same chuffin hillclimb 10ish times a year and a few 1/4 mile sprints lol :wacko:

 

which is also why i dont wanna spend stupid money on an engine, if i were competin nationally then yeh happy days but not just for guernsey!!

 

anyway, welshpug, with Guy Crofts advice i have now matched the carbs to the engine setup and am tryin to work on gettin the car road registered so i can set the ignition timing, looking forward to see how the new carb settings go

Edited July 10, 2008 by wardy18

[Anulfo 22]

Wardy - what gearing are you using? I would guess for a hill climb your top speed is probably 80mile an hour ish. The acceleration of the car will depend on your final drive ratio. changing this will even have a massive impact on a bog standard engine so may be investigate this first as extra BHP is very expensive. Example you could probably get a full on 8v race engine built by Longman for around £10,000 but in my opinion if you are looking to modify your engine a big valve head is definately worth it and you could probably source one second hand. if you are running carbs do you have stand alone ignition set up? This will make a difference too as it means you can set your car up properly on the rollers.

 

Anulfo

[wardy18 33 1 Cars]

Wardy - what gearing are you using? I would guess for a hill climb your top speed is probably 80mile an hour ish. The acceleration of the car will depend on your final drive ratio. changing this will even have a massive impact on a bog standard engine so may be investigate this first as extra BHP is very expensive. Example you could probably get a full on 8v race engine built by Longman for around £10,000 but in my opinion if you are looking to modify your engine a big valve head is definately worth it and you could probably source one second hand. if you are running carbs do you have stand alone ignition set up? This will make a difference too as it means you can set your car up properly on the rollers.

 

Anulfo

 

Im running at 1900 BE1 box with 4:4 cwp, ratios are good, especially as im going to moving from 16" wheels to 15" so will see how the speeds vary, i think this will be enough for the gearing as i also use the car for sprints and dont wanna top out

 

the engine im looking to complete will be:

 

BV 8v Head

Twin 45 Webers

Catcam Rally Cam

Double Valve Springs

H&H Dizzy

60 thou head skim

XU7 lightened balanced crank (to drop to up to 1800cc class)

Custom Rods

Custom Intruder Pistons

Alloy Flywheel

BE1 1900 Box with 4:4 CWP

 

these are the main points so i think this should do to be honest and will be expensive enough

 

Im gonna work on lightening the car a bit more too over the winter, not sure how yet but it needs it!!

[wardy18 33 1 Cars]

also sorry im still on the standard ignition, i always thought that Mapable ignition was mainly for Throttle Bodies?!?!?

 

oh and i have no way of gettin to a rolling road unless i bring the car to the UK (

[welshpug 1,626]

also sorry im still on the standard ignition, i always thought that Mapable ignition was mainly for Throttle Bodies?!?!?

 

far from it, even with carbs or the original injection system a fair amount of tractability and torque can be gained from properly mapped ignition.

[James_R 3]

the engine im looking to complete will be:

 

BV 8v Head

Twin 45 Webers

Catcam Rally Cam

Double Valve Springs

H&H Dizzy

60 thou head skim

XU7 lightened balanced crank (to drop to up to 1800cc class)

Custom Rods

Custom Intruder Pistons

Alloy Flywheel

BE1 1900 Box with 4:4 CWP

 

these are the main points so i think this should do to be honest and will be expensive enough

 

Im gonna work on lightening the car a bit more too over the winter, not sure how yet but it needs it!!

 

How much compression do you want to run? std pistons you can get up to 11:1 ok, you'll see 10.4:1 just putting a Xu9 head on a XU7J4 bottom end.

 

and will you really benifit hugely from a BV head on a smaller engine 1760cc's or will they be big enough at that engine size. And you'd probabaly gain more from mappable ign than the flowed head.

[wardy18 33 1 Cars]

yeh ill run about 11.1 CR, im at 10.9 just from the head skim at the moment

 

i hadnt thought about that, ill find out

 

which mapable ignition is best to go for with carbs?

[James_R 3]

could just save that money too and stick with what you has as it works, espically if all you use it for is 10 events a year why pour even more money in to it.

 

If you're at 10.9 now then you'll be a fair bit higher than the 10.4, quick crunch of numbes suggests 12.1:1 (assuming its just the head skim that's jumped you to 10.9:1 some 7cc's loss in chamber volume. so a thicker h/g to counter that or find a std head to put back on.

[wardy18 33 1 Cars]

Sandy said that with the new crank taking me down to under 1800cc in turn this will reduce my CR even with the large head skim so we can get some intruder pistons to bring this back up to 11.1

 

this si why im tryin to do it a budget as i really dont wanna spend stupid amounts but i want somethin thats quick and gonna kill the competition in the up to 1800cc class )

[benlilly 0]

and will you really benifit hugely from a BV head on a smaller engine 1760cc's or will they be big enough at that engine size

 

I'd second that. I have a Pumaracing BV head for my 1.9 8v I'm building and although it flows very well, turbulence from the short side radius limits the flow to 11.0mm of lift. Not even quite matched to the standard cam. Guy Croft tested this head for me as I bought it second hand. The BV 8V heads he has done without these problems cost ££££.

 

 

Probably best to go with a really good std valve head where the money can be spent on getting the port shape correct and as James R mentioned, the valves are already large enough for 1800cc. Removing the old seats and putting in the oversize vale seats has got to be a time consuming process when there is a bottleneck further up the inlet tract.

Edited July 11, 2008 by benlilly

[James_R 3]

I must have got something wrong, I thought that XU9 chambers were 36cc? Same as GTi-6,R and XU7J4 head chamber (volume) and that starts at 10.4:1

 

Can someone point out where I've mucked up

[welshpug 1,626]

8v chambers are 32cc, Mi16 are 40cc, and as you said James XU7J4 and XU10J4R+RS are 36cc.

[guffe 2]

... and as you said James XU7J4 and XU10J4R+RS are 36cc.

 

I've just measured and untouched XU7J4 head's combustion chamber is just a bit under 38cc...

[welshpug 1,626]

hmm, so have I been misinformed?

[jackherer 543]

8v chambers are 32cc, Mi16 are 40cc, and as you said James XU7J4 and XU10J4R+RS are 36cc.

 

hmm, so have I been misinformed?

 

I've lost count of how many times you have been told about this.

 

- when it comes to technical information and guideance, think twice before you hit

the "submit" button - make sure that information and knowledge you are about to

share is either first hand or verified fact. hear-say and deliberate missinformation

will not be tolerated. "guessing" (within reasonable limits) is allowed if it helps

finding an answer

[guffe 2]

http://forum.205gtidrivers.com/index.php?s...volume+standard

 

Sandy's measurements have been even more precise.

[welshpug 1,626]

ah that's where the confusion came from, 36cc is for a skimmed head, apologies.