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ute54m

The Start Of A New Project

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It's been a long time since I played around with a Datto.... something like 15 years. But it's time to look into the dream project, a 1200 coupe running full S15 running gear.

I've already got the front end (steering, brakes and suspension stuff pretty much worked out (in my head anyway). It'll just be other issues involved in the conversion. I've heard issues with fouling the trans tunnel (this'll be a new one) and possibly the brake booster.

If anyone's got any ideas, I'd love some help.

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welcome mate, sounds like a great project. As for the fouling on the transmission tunnell, you may have to re weld in a new tunnel. Maddat sell tunnels you can weld in. www.maddat.com.au

Check with an engineer whether you can get a 2 litre turbo engine engineered in a 1200 coupe. I had a 1200 ute with an SR20det, so it can be done, but double check. As for the brake booster you can run remote brake booster so that will not foul.

Looking forward to seeing the project begin.

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Spoke to the engineer...

2 Litre turbo can't be done thanks to the little Datto coupe not weighing enough from factory....

I might just have to de-stroke and modify the s@#t out of the engine instead....

SR20 block and manifolds

SR16VE Heads

custom ground crank resulting from comparisons between SR16 and SR20 standard cranks to result in 1800cc capacity

This is going to be a headache!!!

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Can a 2ltr non turbo be registered? If so, why not go the

Autech s15 sr20de

yeah pete the 1200s are engineerable with sr20de. i got one in my sedan. spewin that the dont allow 2 litre turbo in a 1200

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Can a 2ltr non turbo be registered? If so, why not go the

Autech s15 sr20de

yeah pete the 1200s are engineerable with sr20de. i got one in my sedan. spewin that the dont allow 2 litre turbo in a 1200

Imagine how stupid fun it would be if they did :D:devil:

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SR20VE Datto 1200 for the win!!!

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I've already looked into these...

The problem is...

All of the Neo based SR engines are FWD based engines and blocks.... the manifolds and mountings ARE different. I'd have more headaches putting it in than getting it past the engineer.

So far it's looking like a completely custom engine... $$$ Ouch!!!

So far from what I've been thinking...

As SR20 and SR16 both have the same bore size (not sure if the cranks will be interchangeable between blocks)... SR18 and SR20 have the same stroke... looking at a custom ground crank to bring the capacity down to under 1800cc... I've heard shorter stroke engines improve torque as well :-)

So if I've got my info right... maybe

S15 SR20 block and manifolds

SR16 or SR20 VE heads

custom crank getting it under 1800cc

If I go a custom crank, then I may as well go all out... It'll pump out way more than the stock S15 series SR20, but I just can't see it getting done any other way.

Now to find someone that can do the crank...

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I would have thought a custom crank would cost way more than fabricating an aftermarket manifold and extractors.

The whole 16ve bottom end internals go straight into a DE or DET block, so I'd assume an SR18 would be the same.

Anyway I'm pretty sure even if you use a SR20 block, regardless of the capacity you make I haven't heard of the motor being able to be measured for capacity by any engineer? Not saying it's not possible but I would have thought they would just got off the engine number/model of motor to measure it.

VE head conversions aren't difficult, don't know why they aren't more common.

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SR18 has smaller bore size... stroke is the same (therefore cranks would probably be the same). Putting a sleeve into the bore could potentially be a failing issue on the bottom end.

The mechanic that works on my XR8 said you should always be careful playing around with custom inlet manifolds and plenums on injected motors, especially when they are performance based engines. Think of it like comparing standard headers versus extractors... flow improves performance, but we're talking about what goes into the engine, not going out, you want to be careful. Whilst they may not sound overly difficult, plenum capacity and internal surface finish (how smooth the internal walls of the plenum and intake as well as how good the welds are) can have drastic effects on how well the engine performs. One of the reasons for sticking with the standard S15 SR20 inlet manifold - with better heads it should work a lot better at 1800cc as opposed to 1600cc, well in theory at least.

Think about how hard it would be to see the quality of a custom plenum as opposed to a custom crank... well that's my thought.

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As deeznuts said, if you use a 2l block then its a 2l as far as the rta is concerned.

Even though everyone has them, and thats because its easy and legal, a CA18DET will do anything your s15 SR will do.

It doesnt take much to get an 800kg car going

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i always thought a shorter stroke ment more revs and less torque, like a F1 engine silly short stroke no torque at low revs but can redline up to 20 000 rpm!!

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From my understanding (of how it was once explained to me), because there will always be some small elements of friction even though we use oil in the engine, increasing the stroke will disperse the friction heat better allowing for a much larger rev range and increasing top end power. By decreasing the stroke, the torque increases as the maximum revving capability is much lower.

It's always a balance... Torque Vs Power.... Which one do you really want???

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Don't take this the wrong way, but I'd be getting advice from other people. I don't mean this post to sound harsh, but you are really going the long way around to solve a pretty simple problem.

The "torque" argument is way off - there are plenty more factors that come into it than dispersion of friction heat. Stuff like rod angle, even basics like the amount of leverage the rod can impart of the crank will have a much more dramatic effect on torque.

As mentioned, even if you sleeve it down or fit a shorter throw crank to an SR20, the RTA will consider it 2 litre. Realistically, how are you going to prove it to them ? Strip the motor down at the RTA workshop so they can measure the bore and stroke ?? Then strip it down again whenever required after that (ie if its defected for some reason) ?? I'm sure you don't want to do this, and I'm also sure the RTA will just tell you to go away if you try to do this.

Custom plenum affecting performance ? Maybe - but have you considered how reducing capacity by 10% will effect airflow through the standard plenum ? They are designed to work perfectly with a 2 litre engine, but who knows how well they will work with a 1.8l ? You mention that plenum size is important, but one reason it is important is becasue it is tied to engine capacity. Even the heads, saying the 2 litre heads will perform well on a smaller capacity engine is guesswork. Admittedly, its an educated guess, but you really have no way of being sure.

As for "Think about how hard it would be to see the quality of a custom plenum as opposed to a custom crank" - how are you going to see how hard or tough the crank is, whether there are any microscopic cracks or other defects in the crank, etc, etc. Yes, you could have the crank tested, but you could also have the custom plenum tested way easier and cheaper (a borescope inspection of its internals for instance).

I just think you are way over-analysing it. As mentioned, a few mods to an SR16's ancilliaries, bolt it in and away you go.

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Sounds like a lot of work building a custom engine. I know every man and his dog has a CA conversion in a 1200, but it is easy, and you can make good power from them.

If you have the dollars to spend i would go something like this little beauty

0706_sccp_1z+performance_buyers_guide+motor.jpg

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Engineer has said go to the de-stroked SR20 with turbo... woohoo...

crank setup will be around $3500

Do you think I'd have any luck finding a Neo head anywhere??? - Preferably SR16 - N1 spec (apparently they have the most aggressive cam/valve setups.)

Rear suspension setup is organised (whenever the guy finishes the current stuff that he's working on)

So it looks like I'll probably be starting on the outside bodywork... now for another headache... anybody know if there is a way to lose the front quarter window for a 1 piece unit?

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