Is This A Good Idea?

[Peetypug 5]

using parts that I have lying around home and the farm I've been thinking of building an engine for my car.

Basically it will be a 1.9, it will have 1.6 pistons (been told this will lower the compression) a piper 285 cam and a baffled sump from a 16v engine

 

What are peoples thoughts?

Any input welcome

[j_turnell 137 3 Cars]

Using 1.6 pistons raises the compression, not lowers it. Depends what you want out of the engine and what its going to be used for?? I'd get some headwork done also, 3 angle seats and some porting. If your going with a 285 cam, and with the high compression 11:1? worth thinking about carbs and/or some decent management. All depends how far you want to go.

[welshpug 1,661]

sounds a typical recipe that used to be very popular with the rally 205's, not certain on the exact compression figure but it takes it to around 11-1, ideal for a lumpy stick

 

be aware though that a 285 wont work particularly well on a standard intake, would work fine on a set of 45's.

[Peetypug 5]

I thought I'd got it the wrong way round when I wrote it.

Its just going in a standard road car that will only be used at weekends.

I was thinking the bike carb route with a bogg bro manifold.

As for management, I've not thought about it yet

Head work will be done as well

Any ideas on what sort of power it would be?

[welshpug 1,661]

wild stab in the dark at 150+ if it runs right, my 205 felt very potent with the standard intake and a pts rally cam once it got over 2-2.5k just very fussy below that partly due to the standard compression ration and partly due to how the standard intake didnt cope with the pulsing at low revs, sounded mean though

 

for the spark you could get H+H to rebuild your dizzy to suit, as for the carbs I don't think I've ever seen a particularly good result from them, bodies on a decent manifold rigidly mounted yes, but not carbs.

 

I would have a go at sorting the manifold yourself tbh, every bogg bros xu manifold I've seen has been rather short with sharp angles on the runners, I'm not an engine expert but logic from seeing what does work gives the impression that they wont.

[skinner2k3 3]

I am doing the same. 1900 bottom end bar 1600 pistons and flywheel. Carbs and a lumpy cam.

 

Actually have the 1600 pistons and 1900 rods under my desk at the moment waiting to be mated together. Going to try to just press the pins back in without heat, will see how we go. Did a test run with the redundant 1900 pistons and 1600 rods and had no problems.

 

Hoping for in the region of 150+ as well.

[Peetypug 5]

I'm gonna use the 1.6 flywheel too.

 

What are peoples thoughts about my 16v sump? Will it just be a case of using more oil to fill it?

[DamirGTI 342]

I've done something similar bar the cam ... left the OE one , at least for now , but it works just fine so not really fancy replacing it with aftermarket item ... would rather do mappable ignition than the cam ..

 

From the driving/power output aspects , does it all worth a bother - yes ! it's cheap and effective (providing that you do the job by yourself .. at least the major bits .. and tune up the engine properly afterwards as if failed to do this it might go - bang !)

 

Dunno how much this all worths in bhp mark , but i can tell you for sure it really goes like stink wide and increased torque band being most noticeable modification end product .. though 98 RON fuel is a must ! the higher the better along with proper ignition system (mappable would be best but the recurved dizzy is not too bad either ..)

 

Damir

[Baz 421]

The idea in principal is very do-able yes, as said commonly done. I have all the bits for a similar engine, Hi-comp 1.9, PT22 cam with bodies & management for around 160bhp. Just the engine building/time and all the other things i have to do hold me back...

 

Great idea though, Mi power from an 8v, there's something very tempting about that!

 

 

150 on the std inlet plenum? I'm not so sure...

Edited February 3, 2010 by Baz

[DamirGTI 342]

I would have a go at sorting the manifold yourself tbh, every bogg bros xu manifold I've seen has been rather short with sharp angles on the runners, I'm not an engine expert but logic from seeing what does work gives the impression that they wont.

 

Got any pictures or measurements ? i have a few spare ones and i'm willing with the angle grinder

 

Damir

[Peetypug 5]

Thanks gents!

I'm defo going ahead with this.

Due to the amount of parts I have at my disposal I may even try a spot of blue printing!

 

I take it from the lack of response to the ally sump it will be fine.

What about taking a good skim off the head to raise the compression more?

[Anthony 1,003]

Baffled 16v sump from something like a 306 S16 or GTi-6 will bolt straight on, although if you're not running an extended oil pump pickup (which there really is no need to on an 8v) then you'll need to lose the spacer plate. You'll need the matching bolts from the 16v sump as well btw.

 

I've been running this setup (1.9 8v, S16 sump, no spacer) on my own 8v for several years now, and it's been faultless

[DamirGTI 342]

What about taking a good skim off the head to raise the compression more?

 

Why would you want more ? with 1.6 pistons (and 1.9 rods of course .. or better still OE 1.9 DFZ piston/conrod assembly) you'll be @ 11.1 mark which is more than enough if you ask me heavy head skimming just weakens it and retards the cam position in relation to the crank , so id avoid that by all means , if high CR is what you want piston swap is much better solution , even if you dislike the end result you can always remove them out and fit back std. ones -> can do that with the head , once you take the metal off it there's no way back ..

 

Another option (if you want more than 11.1) is in 1.9 SRi pistons , they're fully flat top crown type .. so without the dish .. this ones will do some odd ?12? CR ... or if you have good machine shop could skim/machine the block with the liners , but that might end like disaster if done bad ..

 

Damir

[Peetypug 5]

thanks damir, i think i will leave the head skim to the minimum (i will have 4 heads to choose from)

 

are the rods the same on the 1.6 and 1.9 or will i need to swap the 1.6 pistons to the 1.9 rods?

will i need a machine shop to do this or will i be able to press the pins out/in myself?

is there a chance of damaging the pistons while doing this?

[DamirGTI 342]

No , you'll need to press the 1.6 rods out and press in the 1.9 rods on the 1.6 piston - not so easy job as you've said i wouldn't recommend doing this on a DIY basis especially if it's your first time ... there's special tool for this job and special procedure , will try to dig a few links with this tool so that you can see how it looks like ..

 

Anyway , the best option is using 1.9 DFZ pistons - complete assembly plug and play option piston+conrods .. as this the 1.9 DFZ piston (crown) is the same shape as 1.6 item (same compression height same dish cc volume) but with OE fitted 1.9 length conrod -> perfect choice .. otherwise pack the both set of pistons and take them to the engine recon workshop and let them do the conrod swap job for you , really it'll be the best ..

 

Damir

 

EDIT :

http://forum.205gtidrivers.com/index.php?s...553&hl=tool

http://forum.205gtidrivers.com/index.php?s...624&hl=tool

Edited February 9, 2010 by DamirGTI