CG10 pistons inside a CG13 engine

C

Chrismo

In Holland a tuner told me to fit 1.0 pistons inside my CG13 engine to raise the compression. The things I wonder are: The cr changes but what about the total cilinder volume? Now it's 1300 cc, but what will this become after mounting the CG10 pistons?

I also wonder about the valves. Won't they hit the pistons? Because I also want to get bigger cams, the risk of this will be bigger........

There is very little info about this, and I realy like to know. The tuner I get the pistons from in also not 100% sure of this.




Please help me




gr Chrismo (Holland)
 
No changes should need to be made, and also the CC of the engine will remain the same. as your not changing the bore or stroke.
 
the only way of telling is to take the head off a spare cg13 engine.... get yourself a cg10 piston, have it fitted to the cg13 con-rod, slip it in cylinder number one, cover the top of the piston in thick grease, replace the head and turn the engine over by hand.

if you cant turn it over, that might be your first clue. if you can turn it over... do so a few times then take the head off again and inspect the piston. if there is no marks in the grease, slap 3 more pistons in and off you go...lol


as for the CC's. its the stroke on the cg13 that changes the capacity, the bore is the same.


incidentaly the1275 micra engine is the same bore and stroke as a 1275 mini engine as is the 998cc mini engine and CG10...... some food for thought.


ED beat me to it..
 
chris, the valves wont be any closer, because the 1st point of contact is on the very edge of the piston (nowhere near the dish) :)
 
Hope you're right! Any knowledge about the maximum lift for the cams I want to get?

The CR will get around 10.2:1 , what cams will be best for this ratio?





gr Chrismo
 
chris, the maximum lift i have tried is 10mm, the duration is up to you :)
and the duration will only affect the c/r at low rpm
 
The type of cams I need.......I meen lift and duration. This best suitable for the 10,2:1 cr, big exhaust header, custom intake manifold with 50mm TB and perhaps bigger injectors (this only if a AFR and SACF won't be enough).

Somebody told me there is a sort of calculation to get the best cams suitable for the custom engine, but I don't know where!
Myself I'm thinking to get the Matthew H. cams.





gr Chrismo

frank said:
chris, the maximum lift i have tried is 10mm, the duration is up to you :)
and the duration will only affect the c/r at low rpm
Click to expand...

More duration is less power in lower rpm?
 
chris, i think a formula would only be a rough guide, really the duration is your choice, ie where do you want the powerband, i chose a fairly wild inlet cam which closes the inlet valve @ 60deg after bottom dead centre (so at low revs it,s only compressing for 2/3 of the stroke, and spitting 1/3 of the charge back up the inlet manifold) but once the airspeed picks up the blowback stops and the engine pulls strongly from about 2500rpm.
so if you dont want an on/off switch powerband, go for less agressive cams :)
 
This you tell me I know. But agressive and what's not?

Another thing is I also like to use the car for DAILY use (work home/holiday).
I'm thinking to get some cams from Matthew H, because I know he does many Micra tuning and is known with these engine types!

Only thing is they have two sorts of cams: 254 duration (in and out) 8,43mm lift and 34 degrees overlap. And the Rally cam: 264 duration (in and out) 9,09mm lift and 52 degrees overlap.

This last ones are not VERY big, as I've seen 300 duration cams in a CG13!

Can you tell me what you expect my engine will run with both of these cams? And what cams you would advice me?





gr Chrismo
 
incidentaly the1275 micra engine is the same bore and stroke as a 1275 mini engine as is the 998cc mini engine and CG10...... some food for thought.


ED beat me to it..[/QUOTE]



So will the A series pistons fit
 
they very well may do. i dont think anyone has tried yet.
im sure on the mini forum someone tried fitting a micra head to an a-series block...
 
The 998cc bore on the A series is 65mm, where as the bore on the micra is 71mm.

But the 1275's are an exact match bore wise. The A series has 0.5mm more stroke length. Dunno how much of a difference that makes.

That's with the specs I have. Dunno if the A series ones are right. I'd assume so.

Wrighty, I'd assume you'd want to do it the other way round. I've never worked on an A series, but my friend who does claims at the end of the day, we just have glorified A series engines in our cars?
 
i was sure that the bore on a 998 a series was the same as the 1275 only with a shorter stroke?

what do i know?..lol
 
I have alot of experiance with the a series but have moved on to better things ie japthe a series is a good engine very tunable the last one i built was several years ago it was based round a A+ block using the a EN40 B cooper s crank and matching rods with hepolite powermax pistons a very comprehensive build using the best parts avaliable saw a 1293 produing 124 bhp and 118 ib ft of torque (flywheel power) n/a the only problem was getting a gearbox/diff to hold together .
What i was wondering is can the metro turbo pistons be used in a cg13 im in the process of budinga turbo engine for the micra and know how good the pistons are they are also easily avaliable.
 
its all a case of measuring it, i think the gudgeon pins are gonna be the achilies heal as they are rather small on a micra conrod.

give it a go, i mean nobody else has done it before so your breaking new ground.
 
I ordered some new CG10DE pistons, pistonrings and all gaskets. Also after a long search and a lot of reading I ordered a pair of cams at Matthew Humpries. I bought the Challenge cams, because I need the car for work and all daily needs. Together with the CG10 pistons Matt told me I'd get close to the specs of a original Micra Challenge.

Only thing is how to take off the CG13 pistons, and mount the CG10 ones without damaging them. Is this a job to do yourself, or do I need a engine specialist for the job?
I am a mechanic and fix diesel-engines, so working with these parts is not completely new for me. Only there engines have 2 clips inside the piston to remove the pistonpen, and this CG13 piston-pens are shrinked inside the rods.





gr Chrismo
 
For someone who repairs diesel-engines I'd have thought it would be a piece of cake for you to press out the gudgeon pins and then fit the new pistons.
 
Pugboxter said:
For someone who repairs diesel-engines I'd have thought it would be a piece of cake for you to press out the gudgeon pins and then fit the new pistons.
Click to expand...

These pistonpens are always secured by 2 clips, and can removed realy simpel....even a child can do it!
The pistonpens from the CG13 is something different, and as I am a mechanic, I know how easy it is to damage these things!

Chris

frank said:
i believe matt can do them chris, i think you have to heat the rod to 200deg and use a flypress :)
Click to expand...

I don't have a doubt he can, but in my own country I also have some engine-repair shops who can do the job for me. Also asked this shop the price if he would do some light work on the cilinderhead.

gr Chris
 
Chrismo said:
I ordered some new CG10DE pistons, pistonrings and all gaskets. Also after a long search and a lot of reading I ordered a pair of cams at Matthew Humpries. I bought the Challenge cams, because I need the car for work and all daily needs. Together with the CG10 pistons Matt told me I'd get close to the specs of a original Micra Challenge.

Only thing is how to take off the CG13 pistons, and mount the CG10 ones without damaging them. Is this a job to do yourself, or do I need a engine specialist for the job?
I am a mechanic and fix diesel-engines, so working with these parts is not completely new for me. Only there engines have 2 clips inside the piston to remove the pistonpen, and this CG13 piston-pens are shrinked inside the rods.





gr Chrismo
Click to expand...
Any idea on power output using 254 cams with 1275 pistons?
 

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