Yet Another Turbo Project

[allanallen 528 2 Cars]

evening, any one know how an xm turbo engine gets its low comp ie, is it in the pistons or the head, i'm assuming its the rgx engine.

 

I have a very high milage engine and am guessing the bores will be fooked so was curious about swapping the bottom end for a standard 1.9 or 1.6 bottom end.

 

ive read through loads of stuff on turboing the low comp cat engine (like henry uses) but cant seem to find any info on this swap? help me cheers al

[M@tt 77]

have you pulled the engine out yet? if not get your finger out and get it out and the head off it

[allanallen 528 2 Cars]

have you pulled the engine out yet? if not get your finger out and get it out and the head off it

 

car should be in the garage on sunday hopefully now back on topic mathew

[sonofsam 5]

XM will be RGY (140ishBHP)

Pistons I think.

 

Iron block for Turboing- Thems the rules

[allanallen 528 2 Cars]

XM will be RGY (140ishBHP)

Pistons I think.

 

Iron block for Turboing- Thems the rules

 

rules are there to be broken

 

can anyone confirm its in the pistons, then i'll give up with my stupid cheap skate ideas

[whizzer71 0]

Yep the low comp is in the dish in the piston (somewhat deeper compared to a std XU10 8v piston),I can post some pics tomorrow for you for comparison.

Never compared a XU10 N/A head along side a turbo one so cant comment on that one.

Take a look at the drivers web site projects,theres a alu engined one on there with XU10 turbo and components

 

[allanallen 528 2 Cars]

Yep the low comp is in the dish in the piston (somewhat deeper compared to a std XU10 8v piston),I can post some pics tomorrow for you for comparison.

Never compared a XU10 N/A head along side a turbo one so cant comment on that one.

Take a look at the drivers web site projects,theres a alu engined one on there with XU10 turbo and components

 

 

I'll take a look at that, cheers

 

right so, the rgy uses cut outs in the pistons to lower comp

 

does the rgx engine use the flat top pistons with bigger bowls in the head to lower compression then?

[whizzer71 0]

I'll take a look at that, cheers

 

right so, the rgy uses cut outs in the pistons to lower comp

 

does the rgx engine use the flat top pistons with bigger bowls in the head to lower compression then?

 

Not sure which way around it is,I'll get the code off my engine and post it along with a pic of a piston,This topic has been covered on here before with relevant comp ratios and piston types etc (Ie the difference between the RGY/X engine)

[Henry Yorke 269 3 Cars]

Take a look at the drivers web site projects,theres a alu engined one on there with XU10 turbo and components

Mine is one of these and you have seen how that flies Al!

 

I think the XU10 is in the pistons as has been said. The XU9 I use has its low comp in the head and a touch in the pistons.

 

Might have an outlet for any XM parts as my mate has one! Just had to buy a new exhaust centre section for it and returnofjim did the headgasket too It is my doner when he hydrospastic suspension goes as the engine and turbo are mint Just not sure what to put it in!

[28CRAIG 2]

The head is the same cc on all the xu10 heads 36cc i think but is 34cc on the xu5/9

[inferno 1]

The RGX is a higher compression engine than the RGY IIRC... heads could and probably will be the same.

[tom_m 0]

Yep the low comp is in the dish in the piston (somewhat deeper compared to a std XU10 8v piston),I can post some pics tomorrow for you for comparison.

 

nope the low comp engine uses the flat top pistons

 

I'll take a look at that, cheers

 

right so, the rgy uses cut outs in the pistons to lower comp

 

does the rgx engine use the flat top pistons with bigger bowls in the head to lower compression then?

 

no the rgy (low comp) has the flat top pistons and the RGX (high comp) has the dish

 

 

The RGX is a higher compression engine than the RGY IIRC

 

correct

[whizzer71 0]

So if the low comp has flat top pistons how does it achieve its lower compression,Dont mean to contradict just that normally to get lower compression you dish the pistons ?,I assume that the head volume (36cc) is the same on both engines ?

 

[whizzer71 0]

nope the low comp engine uses the flat top pistons

no the rgy (low comp) has the flat top pistons and the RGX (high comp) has the dish

correct

 

I was reffering to a comparison of the normal 2.0ltr N/A engine which also has marginally dished pistons just not as dished as the turbo ones not between RGY and RGX

[tom_m 0]

So if the low comp has flat top pistons how does it achieve its lower compression,Dont mean to contradict just that normally to get lower compression you dish the pistons ?,I assume that the head volume (36cc) is the same on both engines ?

 

 

 

I was reffering to a comparison of the normal 2.0ltr N/A engine which also has marginally dished pistons just not as dished as the turbo ones not between RGY and RGX

 

i've not measured anything, just reporting what i've seen when taking these engines apart.

 

i assume (yes the mother mother of all f*ck ups) that the dish is built up higher than the top of the flat tops to create more squish or whatever.

 

certainly the top of the flat top piston is still quite a way down the bore at TDC

[whizzer71 0]

Hey Tom just looking at your intended spec at the bottom of you sig,you got any pics or a link to pics that you may have ?

 

Cheers

 

Tris

Edited April 15, 2008 by whizzer71

[allanallen 528 2 Cars]

right, bit of an update. ive got the car home now and ive quickly done a compression test this afternoon, the results were

 

85-60-50-145psi

 

and the intertcooler pipes are full of oil. i'm now thinking this engine will be better left in the car and sent for scrap.

[inferno 1]

whip the head off and have a look, probably a head gasket and maybe turbo seals. certainly not worth scrapping without taking the head off though.

[tom_m 0]

Hey Tom just looking at your intended spec at the bottom of you sig,you got any pics or a link to pics that you may have ?

 

Cheers

 

Tris

 

There are some pictures here

[allanallen 528 2 Cars]

whip the head off and have a look, probably a head gasket and maybe turbo seals. certainly not worth scrapping without taking the head off though.

 

i'm on it this weekend

[returnofjim 0]

i'm on it this weekend

 

I recently did a head gasket change on an xm turbo and it had very deep dished pistons. Ive looked at internals on almost all xu engines and those turbo pistons were different to any others ive seen, whereas all the chambers in the heads looks very similar. Whatever you do dont scrap it, give it to me

[allanallen 528 2 Cars]

I recently did a head gasket change on an xm turbo and it had very deep dished pistons. Ive looked at internals on almost all xu engines and those turbo pistons were different to any others ive seen, whereas all the chambers in the heads looks very similar. Whatever you do dont scrap it, give it to me

 

 

be interesting to see whats inside then

 

not scrapping engine anymore regardless of condition, i'm gonna have a swap round with my engines now, so this ones destined for my 309 (albeit breathed on a bit) now and i'm gonna be finishin off the supercharged mi for in my white 205.

[Henry Yorke 269 3 Cars]

My brother has a low comp 1.9 engine if you want to make a super skip like mine!

[whizzer71 0]

Pics of pistons as promised Normal 2.0ltr 8v and Turbo 2.0ltr 8v

[allanallen 528 2 Cars]

ive had the head off mine now and it has flat top pistons, at tdc the pistons are about 10mm off the deck.

 

its also got some big ass ridges at the top of the bores