1200 pistons in 1300engines

[Andy]

What are the advantages of this? And the combination of parts? heard a few people say about doing this.Basically im thinking of getting a sport engine with the 40's off my mate and was going to build a higher powered engine over the winter and read about this.Also what other things produce good results on the little 1300?
Thinking of building a stripped out featherweight b road blaster for next year
Any help/advice is always appreciated:thumb:

[Damo]

I think it makes them a lazy engine iirc andy but can get some good power gains from this combo too with headwork and the 40s etc.

[Andy]

How do you mean lazy??
Yeah ive heard/seen some interesting power outputs from these little engines

[Novasport]

Unless you need to keep the 1300 block you may aswell use a 1400 block with the 1300 head. It is virtually the same engine & will only be a couple of CC different.

[Novasport]

How can it make it any more lazy than a 1300, its the same crank & rods. It will be less revvy than a 1200 as that has a shorter stroke.

[Andy]

Unless you need to keep the 1300 block you may aswell use a 1400 block with the 1300 head. It is virtually the same engine & will only be a couple of CC different.
14 block with 14 pistons yeah?
Have folk just done the 12 into 13's to stay within regs of motorsport or would it produce more power than a 14block 13head on 40's?

[Novasport]

Its only to gain an extra couple of CC which may be the difference between winning & losing on a rally car but makes no real difference on a road car. It takes you closer to the maximum in the upto 1400cc class.
Yes, just use a standard 1400 bottom end. Earlier carb bottom ends may be stronger but not sure.

My next engine will be a 1300 block with 1200 pistons as I need it to look original externally

[Andy]

Earlier carb bottom ends may be stronger but not sure.
Yeah ive read that on the spec thread in sportzone.Looking for around 100bhp from it,obviously that would require some headwork also.

[Novasport]

The 1300 head would only be of benefit with 40's but a 1400 or 1600 MPi head may be better as standard if you can get the manifold. Not 100% on this, other peeps may know better.

[Sloth]

andy, why not a 1600 on t40's?

[Andy]

Yeah it would be on 40's,been offered a sport engine with manifold,40's irmscher air box and all the bits,unsure if its got the optional cam though,on an f13cr and just wanted to make a decent motor/setup out of it.

[Andy]

andy, why not a 1600 on t40's?
1600's are pretty hard to get these days as they in grassers,and the sport lump is local and a good price;) and keeps in theme with my change of direction for my car

[Edd]

I think if you put a mpi head on a 1300 it will lower th c/r tho

This is one route is could go down when I build up my 1300 turbo

100bhp should be achievable from a 1300 with 40's, cam and head work more I would think

[Sloth]

what bout getting the sport lump and fitting its head etc to a .6 bottom end?

[Novasport]

AST2 cam will be a better option. Prob a very slim chance it will have the Irmscher 108 cam fitted, it was an expensive option new and would prob have been replaced by now. If you are very lucky it may be in there, there should be markings on the end stating X17 or R0258.

[Edd]

1600's are pretty hard to get these days as they in grassers,and the sport lump is local and a good price;) and keeps in theme with my change of direction for my car
Go for it I say

My 1300 has Irmscher injection kit, Kent ast2 cam, enlarged inlet and exhaust valves by 1mm, I hoping that's over 100bhp.

I much prefer a tuned 1300 over any nasty front end heavy XE/LET

[Andy]

what bout getting the sport lump and fitting its head etc to a .6 bottom end?
is that supposed to say 1.6 rob?

[Novasport]

Would an X14XE, C16XE or X16XE not be better?
Its small block and has more scope for power, probably more tuning parts available if you want to go for mental power.

[Sloth]

Yeah Andy.

[Andy]

Would an X14XE, C16XE or X16XE not be better?
Its small block and has more scope for power, probably more tuning parts available if you want to go for mental power.
i did think of those but prefer the idea of the little 8v,not after massive power,just a mildly tuned 8v

[Edd]

Smallblock xe's are quite heavy as well

[mk1nova_rich]

The 1200 pistons bring it up to 1396cc but very high comp, in the region of 11:1 so machining the pistons is advised to bring it down a bit. Mowgli did this conversion so will be able to tell you more

[mk1nova_rich]

It has the potential with the right headwork and cam to be a very torquey motor. Mowgli said he gained around 90bhp on a 1.2 cam and carb IIRC

[Andy]

sounds good,thanks for all the replies

[mk1nova_rich]

im planning on doing it for my road rally Nova, but will most likely keep the high comp, then some nice headwork and manifold to port matching along with a decent carb and lairy cam

[craig green]

You cant put the 1200 pistons in a 1300 block, not without a large re-bore.

You need a 1300 crank & conrods, with 1200 pistons in a 1200 block.

[draper]

Smallblock xe's are quite heavy as well

not that much over an 8v tho - largely irrelevant imo

the tuning potential more than offsets a few kg in weight tho

[craig green]

I dunno, after lifting numerous 8v's about & into cars, My 1.6 XE's were fecking heavy in comparison with a 1600 GSi motor.

[mk1nova_rich]

It is better to overbore the 1.3 (75mm to 77.8mm) rather than fitting a longer stroke in a 1.2 as the bore will be worn to the piston travel of the shorter stroke crank.

[Novasport]

im planning on doing it for my road rally Nova, but will most likely keep the high comp, then some nice headwork and manifold to port matching along with a decent carb and lairy cam

Whats the piston to valve clearance like though?

[mk1nova_rich]

that will need checking and may require some pocketing. But unless the 1.2 pistons vary from the 1.3 in terms of height and crown design then clearance shouldnt be an issue

[Novasport]

I take it the increased CR is due to increased swept volume with the same combustion area/volume?

[mk1nova_rich]

good point to which i could usually give the correct response but my brain switched off hours ago lol but yeh there must be some difference in the actual pistons as a simple answer

[Edd]

Just stick with a standard 1300 bottom end, for all the hassle of it all your not going to gain that much if anything IMO

[mk1nova_rich]

As said before, with the right cam and headwork etc it has a lot of potential, hopefully Mowgli will see this thread and add his bit

[Novasport]

Pistons should be virtually the same in height. The increase in piston diameter would increase the swept volume & the compressed volume but not as much though. This would increase the volume of air/fuel compressed into the similar amount of space hence increasing the CR.

Works in my head, I think?!? Possibly a load of bo-locks buts sounds good to me lol

[mowgli]

put simply, the piston heights are the same, & the valve cutouts are too. the top of the 1200 piston has a smaller bowl.
the main reason i did it was simple... the 1400 was too new at the time (1990), and 1300 engines were everywhere & crazy cheap, i got 2 with an astra mk1 for £20 and the astra got mot'd and used too

all the people who reckon it isn't work the work have never driven one. the 1200/1300 was a way better engine cos it had none of the low emissions & cheap fuel stuff. my 1400 simply had tons more torque than the 1300, and it made for a very quick little car for going cross country with.

[Sloth]

i still think 1600 t40 with thew 1300 head and carbs would be good, anyone know what the cr would be like?

also x16xe motors, fully dressed with an f13 weigh 15 kg less than a fully dressed xe and f20. when i did my mates corsa we weighed the car before and after. its the height and physical size that affects the handling etc.

[Stuart]

i still think 1600 t40 with thew 1300 head and carbs would be good, anyone know what the cr would be like?



err rather ****e.....

Take the GREAT 1.6 8v head off, and replace with smaller valves, poorer flowing ports and mental Cr. I know I'd sooner keep the 1.6 head lol

[mowgli]

would sticking the c14se head on the 1600 bottom end raise the cr much??

[Stuart]

needs measuring... but odds on the heads arent that different etc, so it must be in the pistons

[mowgli]

i will take a look at my big boring piston book & report back later

[garyc]

A decent class 2 autograss 1300 engine does nearly 80BHP at the wheels, that on a std cam, unported head, +40 pistons, balanced bottom end, skimmed head and block. Thats all breathing through a 32mm restricotr plate too. So on a "standard" rebuilt 1300 with twin 40's I think you would almost be at 100BHP.

[Sloth]

between the 1400 and 1600 it is the pistons, basically the 1400 has a raised area in the top the 1600 a dish.

if i was the o.pid buy the 1300, rip the carbs and stuff off it, flog th3e block and bolt it to an mpi 1600....

[Stuart]

and sell the 1.3 inlet to get a proper mpi T40 inlet ;)

[Sloth]

yar, i forgotted that bit lol

[Andy]

Well,some interesting reading here,thanks to everyones input.Certainly gave me some interesting ideas.
I 20xe'd my nova and was not impressed at all,quick in a straight line but unreliable motoring and unpredictable on handling,it just didnt feel good.My old sr 1300 felt much better to drive enthusiastically round here.I wouldnt mind a 1600 on webers,although it would start getting expensive after the manifold and dizzy etc was bought,that money i feel would maybe be better spent on the 1300 on headwork etc?? And ultimately the engine is local,ive not seen a local 1600 for long enough..........

[Sloth]

plenty of 1600's at upullit mate. get a complete one for 100, if you need a hand you know where i am

[SR-Rally]

I have a 1300 engine with 1200st pistons. I built it few months ago and is in the rally car. 100bhp is easy :) mine has lightened crank and flywheel, 1200st pistons, arp rod bolts, worked head, larery cam, 4branch and webber 32/34 carb and I had no problem with bhp, although would like to fit irmscher injection.

[stevie78]

when i first bought my nova years ago it had a 13 sb block 12 pistons a standard 16 head with a kent ast1 cam with 40s had lots of power and that was with the carbs not set still got the block lying in garage if your looking for one