What Can You Do To The 1.6 8v Engine

[jonD6B 0]

So without sounding completely dense what benefits are there to having a 1.6 16V engine over the 1.9 16V engine? How do you overcome the difference in size between 1.6 bores and the 1.9 head?

[mbayley77 0]

I want maximum power in lowest class to start out in rallying which is helped by the 1.6

[jonD6B 0]

I want maximum power in lowest class to start out in rallying which is helped by the 1.6

 

 

Gotcha. Which group are you aiming at?

[mbayley77 0]

Sounds really lame but not sure. I dont have a clue about the classings to be honest.

Bit of confusion here, so has this been done before or is this guinea pig time?

By the way i would be putting them on twin webers if i done this engine build so no management involved.

[Dom9 2]

It's been done a few times before...

 

In theory it is a simple as bolting the Mi16 head to the 1.6 block... But then you would have stupidly low compression and any number of problems...

 

You need to look at what pistons you are going to use, whether Mi16 pistons fit the 1.6 rod (they don't, I believe) so whether you can find some that do fit, or machine flat top pistons like 405 SRi ones to fit...

 

Also, 1.9 camshgaft profiles are not good for a 1.6 engien apparently... It would be nice to see someone build one on here there and find the problems and solve them as they went along, I'm sure we could all pitch in with ideas and advice and you may be able to get something running pretty cheap, it just may not be that great to start with!

 

If you want something with more power that will work out of the box, just buy that 8v XU10 head and get it fettled by Mattsav at QEP and £400 - £500 total should see you with healthy power and still in the 1.6 class with a nice cam and big valves...

[mbayley77 0]

Well if i can lay my hands on the parts to start off this little project then i am more than willing to give it a go. An MI16 head coupled to a 1.6V bottom end.

 

Oh god what am I letting myself in for? Think the works tool room is gonna get some extra work coming there way!

 

Right then. First stage is to find a bottom end of a 1.6GTI then. Hopefully shouldnt be too much trouble to find one for a couple of quid on ebay.

[Tidy_Andy 0]

dave walker wrote about doing some mapping for a guy running a 1600 mi16 in his 206 hot rod in ppc a while ago. it made loads of power with lairy cams will try and find the copy

Edited February 16, 2006 by Tidy_Andy

[mbayley77 0]

That would be great.

What sort of power by the way was it getting?

[DrSeuss 0]

Why not just get a saxo vts engine. Much more capable engine out of the box then a crazy 1.6ltr mi hybrid

[mbayley77 0]

wheres the fun in that?

[205wrc 16]

Here's the car that was doing the Welsh Tarmac Championship with the de-stroked MI16 engine that was allowing it to run in the 1.6 class. I had a long chat with him on one event after we both broke down (different cars). Apparently, the engine was built by Ravic and it cost a small fortune. The car has now been sold and he's building another. If you see the car at a tarmac rally, go over and have a look at it, the engine bay is a work of art.

 

Aled

 

http://www.devilgas.com/r2k3_tour_epynt/viewimg.php?img=31a

[mbayley77 0]

By destroked do you mean the crank was altered in order to decrease the CC of the engine?

[Pierre_b 2]

Hello,

 

By destroked do you mean the crank was altered in order to decrease the CC of the engine?

 

I have read about one XU 1600 16 engine. They start from a XU9J4, fit a 1600 crankshaft and rod. The small end is bushed, to fit the 16s piston pin.

 

That's the only modification reported. I supposed the deck heigt must be checked of course.

 

Pierre

[taffycrook 2]

The ravic built 1.6 mi16 is on std cams as the crank wont last a rally if the cams designed for the job are used.

It has the ability to rev and breathe to 8500-9000 rpm. Power then equals 220-240 bhp.

Std 1.6 crank whilest good isnt much use above 7500 rpm.

All steel btm end required. Along with custom forged pistons.

Uprated valve gear, oil pump(dry sump)

Cost you about £7K

 

Still fancy it?

[mbayley77 0]

Right then.

How about a build for £50 and whats lying in the garage and see if it will last a couple of hard runs ha ha. the seven grand can keep on whistling

 

Still gonna do something along these lines. Never had a bottom end go. Does it go with a bang

[Baz 421]

Good on ya chap! only just spotted this post! Thought i'd read somewhere that the Mi head doesn't match up with 8v blocks 'cos of water and/or oilways, as i did a bit of research while back as wanted to use my s16 head on 1.9 8v alloy block. -otherwise would've thought we'd see it alot more often, altho i could be getting confused with s16 to Mi16 compatability! Keep up that optimism tho! Very interested to find out how it all goes, keep us all posted won't you!!

[taffycrook 2]

Right then.

How about a build for £50 and whats lying in the garage and see if it will last a couple of hard runs ha ha. the seven grand can keep on whistling

 

Still gonna do something along these lines. Never had a bottom end go. Does it go with a bang

 

 

£50 wont buy you the gaskets to put a mi16 back together.

This subject comes up time and time again, there is no easy/cheep cure for the CR problem that lets you run the cams to make the power which due to capacity can only come from increased rpm.

eg 1.9 std makes 160bhp thats equal to 134 bhp at the same rpm from the 1.6. Going by the % difference in capacity.

So to make 160 it needs to turn at about 7700 rpm. This is above the std crank safe limit.

Now the above isnt perfect as I know that you get more from the 1.6 at 7700 with carbs or T/Bs.

And a well sorted 1.9 mi16 can make as much as 185 bhp at 6850. So a similar 1.6 would make 155 bhp.

185 bhp from a 1.6 requires close to 8200 rpm using the above theory. The truth is more than likely to be below this but not much.

[Pierre_b 2]

Hello,

 

£50 wont buy you the gaskets to put a mi16 back together.

This subject comes up time and time again, there is no easy/cheep cure for the CR problem that lets you run the cams to make the power which due to capacity can only come from increased rpm.

 

Sorry for my bad english, but you say that the cams are too "big" for the CR you have ? You are speaking of an engine with 16s piston with XU5 crank/rod or with XU5 piston ?

 

eg 1.9 std makes 160bhp thats equal to 134 bhp at the same rpm from the 1.6. Going by the % difference in capacity.

So to make 160 it needs to turn at about 7700 rpm. This is above the std crank safe limit.

Now the above isnt perfect as I know that you get more from the 1.6 at 7700 with carbs or T/Bs.

And a well sorted 1.9 mi16 can make as much as 185 bhp at 6850. So a similar 1.6 would make 155 bhp.

185 bhp from a 1.6 requires close to 8200 rpm using the above theory. The truth is more than likely to be below this but not much.

 

I agree with your theory. The real question is that in a 1600 class, what engine do you choose, a TU5J4 with ~130 hp stock, of a XU5J4 (miam) with ~130 hp "stock"?

What's the pb with the XU5 crank over 7000 rpm ?

[mbayley77 0]

£50 wont buy you the gaskets to put a mi16 back together.

 

Please re-read my post "and whats lying in the garage" now if you know that i dont have gaskets then what the hell you doing in my garage?

[mrknighty1 0]

I've got a 1.6 Gti with:- twin 45's, Ported head, Piper BP300 cam, flywheel lightened by 25% fully balanced with the mega jolt mappable ignition + c\r boxs

 

It loads of fun to drive and luvs to be reved. I used a G-tech meter to time the 0-60 before the gearbox and ignition was fitted and got 6.8sec.

[taffycrook 2]

Hello,

Sorry for my bad english, but you say that the cams are too "big" for the CR you have ? You are speaking of an engine with 16s piston with XU5 crank/rod or with XU5 piston ?

I agree with your theory. The real question is that in a 1600 class, what engine do you choose, a TU5J4 with ~130 hp stock, of a XU5J4 (miam) with ~130 hp "stock"?

What's the pb with the XU5 crank over 7000 rpm ?

 

Cam size is measured in lift and duration, and both of these effect how much piston crown can enter the combustion chamber.

Crank isnt safe over 7000 rpm without work and upper limit is near 7500 rpm. I am unwilling to try this in practice and therefore reason a steel crank and rods along with forged pistons is the answer.

This isnt to say that they will let go at those speeds but if you go there too often it will.

Tu engine has a lot going for it, but isnt in the same leauge as a mi16. In terms of gas flow out of the box, plus its btm end is made of chocolate. So both engines require expensive parts to turn out big power.

But for road use I would plumb for a TU if it has to be 1.6 and 16v.

[Dom9 2]

What is the stroke of the XU7 1.8 16v crank? I'm assuming it has the same bore as the 2.0 XU engines? If so, the bore of the 1.9 engines is smaller, so if the 1.8 crank was used in a 1.9 block, assuming it fits, which I'm guessing it should, I wonder what capacity that would bring the engine to?

 

May not be as low as 1.6, but it might be around 1.7, which is one of the class breaks in sprinting, is it not?

[pug_ham 240 3 Cars]

What is the stroke of the XU7 1.8 16v crank? I'm assuming it has the same bore as the 2.0 XU engines?

The XU7 stroke is 81mm but bore is same size as XU5 & XU9.

 

Its basically the same engine, alloy block wet liner design.

 

Graham.

[Dom9 2]

Bugger...

[205_19_T 0]

Good on ya chap! only just spotted this post! Thought i'd read somewhere that the Mi head doesn't match up with 8v blocks 'cos of water and/or oilways, as i did a bit of research while back as wanted to use my s16 head on 1.9 8v alloy block. -otherwise would've thought we'd see it alot more often, altho i could be getting confused with s16 to Mi16 compatability! Keep up that optimism tho! Very interested to find out how it all goes, keep us all posted won't you!!

 

Quite sure the mi16 head will go on without a problem. In fact all XU 16v heads should work fine. I used a 2.0 16v head for my car. And as far as the wetliners are concerned I don't think of it to be a problem as long as the rotating parts are decently balanced. I make loads of horsepower with the redline at 7000 rpm (although I don't get there really often) with a wetliner 16v engine.