Front Engined, Rear Wheel Drive N/A C1j Build

[Os8472]

With my GTT pretty much finished I find myself with not alot to do, so I've taken on a little side project, basically my brother is restoring a 1972 Triumph Spitfire 1500, he is handling the body work and I've been tasked with building the engine.

Now the standard spitfire engine is a 4pot 8 OHV 1500cc engine, with a 3 main bearing crank, 75bhp and revs to 4000rpm before it eats itself, even the best race built engines didn't rev beyond 4500rpm, the engine is an iron block and iron head and weights in at a ton or near enough, no joke the block with nothing in it weights about the same as a complete C1J bottom end so weight is a big factor aswell as reliability and power.

My brother had an R5 as his first car, just GTL nothing special but he bought it to last 4, 5 months, it lasted 5 years and reached 150,000miles before he decided it was time for a change and the engine still ran sweat as a nut so we both know in N/A form the C1J will go forever. To that end its a C1J thats going in the spitfire, now it won't bolt straight in but I don't think it'll take much hammering to make it fit.

I'll be building this engine with a N/A C1J block, pistons, cam and flywheel but I will be using a GTT head for the bigger valves. Fuel will be fed through a pair of SU carbs and I'll have to make a custom tubular exhaust manifold to meet up with the rest of the exhaust system.

I plan on port and polishing the head and raising the compression ratio abit, I won't be messing with the ignition much just yet so I'll be using the C1J flywheel and renix unit to control the spark, maybe I'll knock the tdc sensor foward abit for some advance but that can be done anytime.

Now I've started by getting my spare GTT block out of the shed along with a flywheel, a spitfire gearbox and mounting plate so I can begin measuring up what needs doing to mate the C1J block to the spitfire gearbox, fortunatly triumph used a plate to mount the box to the engine so I just need to get this redrilled to suit the C1J bolt pattern which shouldn't be to diffecult.




However I have 1 problem, in an R5 the engine tilts backward abit but the spitfire engine doesn't, there is room in the engine bay for it to tilt but is there any reason why it should tilt?

You'll see from the pics below I've placed the plate on the engine in the 2 postions, the first with the plate if the engine was tilted and second with the engine in a vertical positon, what you'll notice with the engine vertical the front webbing on the block overlaps the hole in the plate for the starter motor but it doesn't with the engine tilted.




Come on peeps, tilted or not? for and against please

[Lewis]

Why not use a n/a gordini head? Even better still

[TNT ANDY]

Come on peeps, tilted or not? for and against please[/QUOTE]

Tilted, so that you can get the starter motor in easily - but why this engine in this car??? Is the spitfire a weighty item?

I wouldn't think the incline would have a major impact on the running of the engine as the oil pick up is at the mid / front???

[Os8472]

Why not use a n/a gordini head? Even better still

I've tried to get 1 but they go for silly money and there's no point unless you get the 10.1 comp pistons aswell which cost nearly 400quid

[Os8472]

Come on peeps, tilted or not? for and against please

Tilted, so that you can get the starter motor in easily - but why this engine in this car??? Is the spitfire a weighty item?

I wouldn't think the incline would have a major impact on the running of the engine as the oil pick up is at the mid / front???[/QUOTE]

The spitfire engine is bloody heavy and a piece of ****, makes a c1j look advanced.

The main reasons are the c1j is a better engine, more reliable, will make more power, better economy, lighter but looks almost identical

[TrixNFlix]

I thought the angle was for oil drainage from the head.

[michael tierney]

c1j is a derivative of the r12 and r18 ect.which were vertical.the main reason its tilted is to put more weight behind the front axil for handling ect,sump and inlet manifold are only angled because of the lean back angle of the engine!...mount it vertical

[MFaulks]

This sounds great Os

SU carbs are good, and will work well. Try and keep the heat soak down, as you'll have the issues of the non-cross flow head.

Get some nice big inlet valves thrashed in the head, good seat and throat cuts and then you'll be able to DIY port no problem. I would put inserts in as well, lift the exhaust valve and get some strong blowdown and scavenge going on. Good cam and headers and it will fly.

I would ditch the Renix and graft on a simple 2D map prog ignition system, nice and cheap and very effective.

Sounds fun!

[Sparkie]

you need to find out what compression ratio the N/A engine you have there is running. i built a NA 1.4 for a mk1, using a 1.4 block and a 1.1 head, compression was about 11.2:1, but i ran a N/A piper 285, which is actually 288deg.

if money/time was tight, id use a twin choke weber on the standard manifold.

also the engine isnt canted over in the mk1, so having it upright will be fine.

[Andrew Cooke]

you'll want the sump and oil pump from a vertically mounted C series, and something to make the carb sit vertical.

[Andrew Cooke]

ooh, tell you what, if you fancy FI I have the original Twingo engine sat here

[Os8472]

I thought the angle was for oil drainage from the head.

Thats what I thought

[Os8472]

This sounds great Os

SU carbs are good, and will work well. Try and keep the heat soak down, as you'll have the issues of the non-cross flow head.

Get some nice big inlet valves thrashed in the head, good seat and throat cuts and then you'll be able to DIY port no problem. I would put inserts in as well, lift the exhaust valve and get some strong blowdown and scavenge going on. Good cam and headers and it will fly.

I would ditch the Renix and graft on a simple 2D map prog ignition system, nice and cheap and very effective.

Sounds fun!

Because I'll be making a tubular exhaust manifold that will drop straght down, heat shouldn't be as bad as on a GTT but I'll Be making a heat shield to sit between the manifolds anyway.

I'm gunna let my machine shop man do the head work as he knows his **** and has done a GTT head before.

I'm gunna stick with the renic to start with as its nice and simple, long term we will be thinking about a proper stand alone system with a coil pack to get the best out of it.

[Os8472]

you need to find out what compression ratio the N/A engine you have there is running. i built a NA 1.4 for a mk1, using a 1.4 block and a 1.1 head, compression was about 11.2:1, but i ran a N/A piper 285, which is actually 288deg.

if money/time was tight, id use a twin choke weber on the standard manifold.

also the engine isnt canted over in the mk1, so having it upright will be fine.

The N?A C1J engine is a 9:1 compression ratio apparantly, I was planning on skimming the block and liners abit to raise it a little but not to much and as I want to make this a rev happy engine.

I was going to stick with the stock cam for driveability, power isn't the main objective with this engine but thats not to say I won't get the most out of it.

The twin choke webber is what they used on the C2J which made 72bhp instead of 60bhp, as far as I know that was the only difference, We'll be using a pair of SU's so that should be plenty enough.

[Os8472]

you'll want the sump and oil pump from a vertically mounted C series, and something to make the carb sit vertical.

Don't happen to have them do ya?

ooh, tell you what, if you fancy FI I have the original Twingo engine sat here

what condition is it in? how much you want for it?

[markey b]

my old camparse had twin choke webber, with a 2part manifold like a gtt, think i got it off an auto back in the day

[Andrew Cooke]

Don't happen to have them do ya?



what condition is it in? how much you want for it?

sorry, I'm pretty sure I binned that lot.

it's running condition, but sat outside, I'm guessing it's the original 180,000km engine. You could just have the head, inlet, loom etc if you wanted as I'd keep the block and crank as spares, or take the lot if you'd rather. £50 and you can take as much or little as you fancy. I' think it has bigger valves than the GTT.

[Os8472]

sorry, I'm pretty sure I binned that lot.

it's running condition, but sat outside, I'm guessing it's the original 180,000km engine. You could just have the head, inlet, loom etc if you wanted as I'd keep the block and crank as spares, or take the lot if you'd rather. £50 and you can take as much or little as you fancy. I' think it has bigger valves than the GTT.

Sounds perfect, head, cam, push rods, cam followers, loom and rocker shaft would be nice, how long can you hold on to it for me?

[Andrew Cooke]

Sounds perfect, head, cam, push rods, cam followers, loom and rocker shaft would be nice, how long can you hold on to it for me?

I suppose I could do with getting rid this year, it's turning into too much of an ornament

[Os8472]

I suppose I could do with getting rid this year, it's turning into too much of an ornament

I can come and pick it up early october, that ok with you?

[Andrew Cooke]

I can come and pick it up early october, that ok with you?

that would be ok

[Sparkie]

The N?A C1J engine is a 9:1 compression ratio apparantly, I was planning on skimming the block and liners abit to raise it a little but not to much and as I want to make this a rev happy engine.

if you put a more lairy cam it will be rev happy, as i think (although i maybe wrong here) the dynamic compression lowers due to the overlap/ valve duration.

[michael tierney]

hi oz! if u decide on su's give me a shout,i have a pair of manifolds for hif's

[Os8472]

hi oz! if u decide on su's give me a shout,i have a pair of manifolds for hif's

Sounds interesting, how much u want? Got any pics?

[Os8472]

if you put a more lairy cam it will be rev happy, as i think (although i maybe wrong here) the dynamic compression lowers due to the overlap/ valve duration.

Gunna use the stock cam to start with and change it latter on once we've got everything up and running right. Any advice on what cam to go for?

[allanr5gtt]

i dont know if this is any good for you?

http://cgi.ebay.co.uk/renault-5-gord...item2a08b4eb37

[michael tierney]

about £40 posted to uk

[Os8472]

i dont know if this is any good for you?

http://cgi.ebay.co.uk/renault-5-gord...item2a08b4eb37

Awesome, cheers for that fella, i hope no one else starts bidding

[Andrew Cooke]

Awesome, cheers for that fella, i hope no one else starts bidding

You'd be better holding out for a complete gordini engine, or even car. That way you'd get all the bits you need including the sump.

[JRP]

Ive got a whole engine can a c1j not be used with a gordini head.. a few changes needed>?

[Os8472]

Ive got a whole engine can a c1j not be used with a gordini head.. a few changes needed>?

Have you now, how much you want for it?

I think its been done before, the block is pretty much the same so I can't see why not

[JRP]

Have you now, how much you want for it?

I think its been done before, the block is pretty much the same so I can't see why not

Built up and ready to drop in... £8k?? sound fair? What car is this gonna go in again?

[Os8472]

Built up and ready to drop in... £8k?? sound fair? What car is this gonna go in again?

yikes ok maybe I'll keep looking, thanks anyway

[michael tierney]

pics posted above

[Os8472]

about £40 posted to uk

They look perfect, what are the threaded holes on the top of the runners for? 1 way valves?

I think your the chap that built my efi manifold, and these are anything like that they should work perfect

[Os8472]

just had a look at the carbs we've got and there the SU HS4 carburettors which have a different bolt pattern to the manifold than your adaptors, do you have any other inlets Michael?

[michael tierney]

the holes are m12 to adapt the one way valves,i think i still have them somewhere.i have no other inlets like those,like i said they're for the hif type...38 or 44mm,adaptors might be sourced on ebay though(from the 4 bolt type to the two!!)
your not going to efi it are u?

[Os8472]

the holes are m12 to adapt the one way valves,i think i still have them somewhere.i have no other inlets like those,like i said they're for the hif type...38 or 44mm,adaptors might be sourced on ebay though(from the 4 bolt type to the two!!)
your not going to efi it are u?

Ok cool i'll have a look.

Nah the efi manifold is on my r5, works a treat, had to mod it abit to suite my setup but it cured all the problems i was having with the old 1

[michael tierney]

that great to hear...any power runs yet or mpg figures?i'll have 2 different types of injection manifold available in about 2 months(hopefully)

[Os8472]

that great to hear...any power runs yet or mpg figures?i'll have 2 different types of injection manifold available in about 2 months(hopefully)

Ain't got any power figures yet but it does 45mpg

[TNT ANDY]

that great to hear...any power runs yet or mpg figures?i'll have 2 different types of injection manifold available in about 2 months(hopefully)

Mines on and just waiting for a mapping sesh, will keep you posted. Looks the biz

[allanr5gtt]

Mines on and just waiting for a mapping sesh, will keep you posted. Looks the biz

any pic's andy?

[Os8472]

Right been a while since I did anything about this, so here's a quick update.

My boss's kid does gokart racing and he brought a load of spares into the office on monday, I spotted 1 of the carbs and thought that it could be of use, well when I say 1 I mean 4.





Its only 60mm long, has a 20mm butterfly, seeing as a GTT only has 1x25mm carb I figure 4x20mm carbs will be plenty of air flow for an N/A 1.4 on a custom inlent manifold and even if the jets can't flow enough fuel they could easly be blocked and a set of injector bosses fitted to the inlet to allow for efi.

I think these could even work on a GTT as they are air tight combined with injectors in a manifold, stand alone management and bingo you've got throttle bodies and efi for a GTT.

[TNT ANDY]

[michael tierney]

if u give 1 cylinder a 20mm carb it will be too small....i found this out by putting 2x32dis carbs on the gt turbo and producing the same power but more torque.the size of the cylinder(350cc)determines the carb size.airflow at optimum rpm

[Andrew Cooke]

I can come and pick it up early october, that ok with you?

it's early October

[Os8472]

Andrew Cooke reminded me it was october so I took a trip to his place on sunday, yay I love a 2 1/2 hour each way motorway drive in the 5 with hard suspension anyway once there we pulled apart the old C series engine that was in his twingo before the 172 engine snuck its way in (awesome car by the way, top work Andrew).

I've had a chance to give the head a good going over and found some interesting differences to my spare ph1 GTT head, I figured someone might be interested, proberbly not and I'm proberbly talking to myself again

First off the 2 heads next to each other, the GTT head is the bottom one.


First major difference to the ph1 GTT head is the valve spring base, on the ph1 head he valve springs sit ontop


Where as on the Twingo they sit in a sort cup to prevent sideways movement, this is also found on the ph2 GTT heads


Next the inlet ports, on the ph1 GTT head they are 26.93mm across and more square shape


And on the twingo they are 28.06mm across but are a circular shape


This GTT head is 73.29mm thick with only 1 skim


The twingo head is 71.61mm thick with as far as we know, no skims


The GTT combustion chamber


The twingo combustion chamber, very different in shape, one side tapers towards the exhaust valve and the side the spark plug comes in is has a triangular shape


The GTT exhaust valve is 28.54mm


And the twingo exhaust valve is 29.94mm


The GTT inlet valve is 33.73mm


The twingo inlet valve is 32.98mm


Its obvious renault continued to work on the C series design right up until they stopped producing it, the twingo head is very much designed for N/A applications and would be to high a compression to use on a GTT but for the engine I'm building it should be perfect.

Did abit of research in the twingo aswell and found out that its 1200c engine produced 60bhp using single point injection and a Cat the N/A C1J found in an R5 GTL produced 60bhp and that had a single throat carb, 1400cc and no CAT, renault sure did something different with the twingo engine. Looking over the one out of Andrews car it still used a dizzy and the cam according to Andrew is mild so having a better head and single point injection must have made alot of difference, I bet on a 1400c bottom end with a pair of SU Carbs and abit of porting and polishing should make plenty of power, maybe in the long run with EFi and a coil pack it'll make even more, can't wait to find out.

[Andrew Cooke]

looks like I made a mess of measuring that exhaust valve

I guess it's a pity I didn't pull it off earlier and flow test the head, still, I have to leave some work for you to do

I think the cam had 5mm lobe lift, to compare that:
PH1? GTT 5.13mm
PH2? GTT 5.6mm
C3J 5.07mm

https://www.rtoc.org/cam/?cam=std+GTT...vance=0&vc=0.2