1.6 Into 1.9

[mrfirepro 127 1 Cars]

I have recently acquired a fully stripped and prepared 1.6 engine with lots of new parts and a really clean head and block. My source could not tell me the history except he got it with a car that he bought for the shell only.

 

I understand that many parts are the same, as these items are either new or perfect I would like to build them into my 1.9 engine rebuild, rebuild, can I use the following parts...

 

1.The Block - Is spotless has been cleaned and painted and has zero internal corrosion

2. The head - this again is spotless with no carbon or any other deposits anywhere(very shiney), the exhaust valve head size is 35.12 and the intlet is 41.55 (both more than either 1.6 or 1.9 spec )

3. Pistons - Brand new still in box made by Kolbenschmidt with brand new rings and pins (part number 90 382 970)

4. Conrods - Old conrods but with new bolts

5. Crank - Looks very clean

6. Cam - again looks very clean, have measured the cam lobes against a 1.9 and the 1.9 lobes are slightly bigger)

7. Liners - Brand new

 

I have not tested and measured any thing with any great details, if the above parts can be used I would then take them to the machine shop for testing/checking

 

thanks

[welshpug 1,662]

1&2, block and head are identical for 115 bhp 1.6 and 128 bhp 1.9 engines, as well as 122 bhp motronic 1.9's afaik.

 

3, 1.6 pistons can be used in a 1.9, this will give a very decent increase in compression, probably far too much for a standard camshaft however, but ideal for a healthy cam upgrade, however the wilder you go the more you need to spend on the valvetrain to withstand the RPM of the rev range and ramp angle of a wilder cam.

 

4. conrods, NO, they are longer on a 1.6.

5, crank, NO, shorter stroke on a 1.6.

6, cam, best to use whichever cam matches the capacity of the engine, they are different specs.

 

7, liners are the same.

[mrfirepro 127 1 Cars]

thanks WP.

 

have a few more questions if that's OK.

 

1&2 so, OK to use the cam from my 1.9 in the 1.6 head??

 

Pistons - Have done a search on the part number and think it could be a 1.9 as it's got a recessed head (am I correct that this is the difference between 1.6 & 1.9?)

 

My measurement of the exhaust valve head are only rough but it is bigger than spec, will this cause any problems??

Edited July 7, 2014 by mrfirepro

[welshpug 1,662]

yes, cam will swap fine, it will need re-shimming, the shims are under the bucket tappets, fit cam, check clearances, remove cam measure shims and fit different shims of appropriate thickness.

 

the dish in the piston is indeed the difference between them, 1.6 does have a dish but not as large as the 1.9, you need to make sure which variant of the 1.9 they are for if so, as some were flat topped to work with a much larger chamber in the head.

 

valve clearance is generous on these, so you wont have issues.

[mrfirepro 127 1 Cars]

excellent WP...as usual..

[pug_ham 244 3 Cars]

A 1.9 cam in a 1.6 engine isn't a good mix imo, I along with a few others on here have run this mix & the 1.6 engine looses a little of its zesty rev happy feeling with one fitted.

 

g

[mrfirepro 127 1 Cars]

Hi Graham,

 

Thanks for the pointer, this is my plan, was it this sort of arrangement that gave problems?

 

Hopefully if I get it right it will be a 1.9 engine as will transplant all the usable parts from the 1.6 into the 1.9 engine. My most important item is the block, I now have got through 7 blocks (mainly bad corrosion) and this one looks like it's never been used, it's that clean with no corrosion.

 

So after the plan is...

 

existing 1.9 crank (ground and balanced)

new pistons and rings (happen to be 1.9 strangely enough)

Existing 1.9 con rods

1.6 head with 1.9 cam (again strange sizing of valves, dont match 1.6 or 1.9)

1.6 block

New liners

 

Now taken all the parts to the machine shop so they can check and measure all the items, once done they will fit the con-rods to the pistons, prepare the head and block & regrind the crank.

 

I hope this all sounds workable???

Edited July 8, 2014 by mrfirepro

[jackherer 543]

If the valves are smaller it might be a pre 1987 1.6 which only had 105 BHP as opposed to 115.

[mrfirepro 127 1 Cars]

Good point..

 

The valves were not removed so could not be 100% accurate but the inlet is about on spec for a 1.9 (41.6) and I measure the inlet valve at 41.55. It's the exhaust that seems much bigger haynes says XU5 of 32.95 and XU9 of 34.5 and I measure 35.12.

 

I was wondering if it was the other way round and someone was putting a 1.9 head onto a 1.6 block??? (is this ever done??)

 

BTW I found the dished washer for the struts if you want them (been plated)

Edited July 8, 2014 by mrfirepro

[jackherer 543]

From launch in 1984 the 205 GTI 1.6 had relatively small valves until 1987 when the 1.9 was released, from that point both 1.6 and 1.9 had identical sized valves. Assuming that measurement from Haynes is correct I'm not sure what head you have, do the ports look standard/factory finished? There was a phase a few years ago when people were fitting XU10 heads which apparently have larger valves but I don't know how you identify them.

 

The dished washers would be handy, thanks, I'd be happy to cover postage or whatever and I still owe you one for the other bits!

[mrfirepro 127 1 Cars]

The smaller valves have a small reccess in the centre which I have not seen on any of the other heads I've taken off.

 

are you going to pugfest? can bring them with me or wait until I'm next in Witham

[Stu 18]

Im very interested in this topic, as i too have a good 1600 engine that i'd like to transplant some bits into from a 1900 that has believed to have seized (i didnt drive the car prior to it dying, nor have i investigated).

 

Sorry to gatecrash, but would i be right in thinking that if i take the complete 1600 and swap the crank and rods from the 1900 i'll have a high compression 1900 engine?

 

WIth the sump spacer and such obviously.

 

Ill be watching with interest, be good to see what the final proposal build consists of, and how it goes together

Edited July 9, 2014 by Stu

[welshpug 1,662]

You only get increased compression from the smaller dish In the 1.6 pistons, so those need using if you have that in mind.

 

It will work without the stiffening piece, but worth fitting it if you have one.

[Stu 18]

Well given that the 1900 could well have overheated or whatever i'd planned on using the 1600 pistons mainly for this reason, but the increase in CR is a secondary bonus

 

Anyhoo.. Back to topic

[jackherer 543]

are you going to pugfest? can bring them with me or wait until I'm next in Witham

I'm not going to make Pugfest now unfortunately

[Anthony 1,003]

There was a phase a few years ago when people were fitting XU10 heads which apparently have larger valves but I don't know how you identify them.

Easiest way to differentiate the heads at a glance is to look at the spark plugs / HT leads - on XU5/7/9 heads the plugs are vertical whereas on a XU10 they come out at an angle. The inlet port shape is different too - roundish on an XU10 and squarish on an XU5/7/9, but obviously you can't see that with the manifold fitted.

[mrfirepro 127 1 Cars]

Easiest way to differentiate the heads at a glance is to look at the spark plugs / HT leads - on XU5/7/9 heads the plugs are vertical whereas on a XU10 they come out at an angle. The inlet port shape is different too - roundish on an XU10 and squarish on an XU5/7/9, but obviously you can't see that with the manifold fitted.

Anthony,

 

Nice info, will check when I get the head back.

 

Stu,

 

Don't forget you will need the sump spacer as well. Mine should be done in the next couple of weeks I'll let you know how I get on.

[pug_ham 244 3 Cars]

Hi Graham,

 

Thanks for the pointer, this is my plan, was it this sort of arrangement that gave problems?

 

Hopefully if I get it right it will be a 1.9 engine as will transplant all the usable parts from the 1.6 into the 1.9 engine. My most important item is the block, I now have got through 7 blocks (mainly bad corrosion) and this one looks like it's never been used, it's that clean with no corrosion.

 

So after the plan is...

 

existing 1.9 crank (ground and balanced)

new pistons and rings (happen to be 1.9 strangely enough)

Existing 1.9 con rods

1.6 head with 1.9 cam (again strange sizing of valves, dont match 1.6 or 1.9)

1.6 block

New liners

 

Now taken all the parts to the machine shop so they can check and measure all the items, once done they will fit the con-rods to the pistons, prepare the head and block & regrind the crank.

 

I hope this all sounds workable???

Hi Graham,

 

Thanks for the pointer, this is my plan, was it this sort of arrangement that gave problems?

 

Hopefully if I get it right it will be a 1.9 engine as will transplant all the usable parts from the 1.6 into the 1.9 engine. My most important item is the block, I now have got through 7 blocks (mainly bad corrosion) and this one looks like it's never been used, it's that clean with no corrosion.

 

So after the plan is...

 

existing 1.9 crank (ground and balanced)

new pistons and rings (happen to be 1.9 strangely enough)

Existing 1.9 con rods

1.6 head with 1.9 cam (again strange sizing of valves, dont match 1.6 or 1.9)

1.6 block

New liners

 

Now taken all the parts to the machine shop so they can check and measure all the items, once done they will fit the con-rods to the pistons, prepare the head and block & regrind the crank.

 

I hope this all sounds workable???

Sorry for the slow reply, I missed this topic on my last few visits.

 

That combination will be fine imo, I did that with my old track car (the black one) basically putting all 1.9 internals into the existing 1.6 block to keep the numbers correct.

 

Only difference I'd have considered would be using the 1.6 pistons but tbh if you have new 1.9 pistons you can achceive a similar gain with a head skim so it'll be fine.

 

g

[mrfirepro 127 1 Cars]

thanks G,

 

Machine shop have been terrible so got the parts back (only did pressure test)

 

Have had block and head vapour blasted, got them back today. Will take them to new machine shop tomorrow.

 

will build as above, so hopefully all will be OK.

[Mac Crash 78 1 Cars]

Paul,

 

If it isn't too late then I'd seriously consider after all the good work your doing buying a new fast road cam for your build, you'll see real, worthwhile gains from this with your increased CR, it'll be night and day to standard and still have decent road manners.

[mrfirepro 127 1 Cars]

any particular spec, make, part number, supplier....

 

What are the downsides of this, if any?

[welshpug 1,662]

depends very much on the ecu and inlet you're using, a mappable ecu you can go much further on the duration, quite a few of us have had decent results with a 272 ish cam on the std inlet, anything much further needs more compression and manners on a single throttle become a little poorer at lower rpm, its not an issue on itb's though.

[Mac Crash 78 1 Cars]

Piper 270, tried and tested, it was always the cam that gave the best results for stock/OE applications, I reckon what WP is saying is spot on because the tuner who built our first 1.9 GTi engine (20 odd years ago) wouldn't go any further than this as the car was road based, anything further is no longer really fast road and that's another ballpark, you'd start to lose/compromise bottom end response and torque which is what makes the 1.9 so good in the first place, there are no downsides to the 270, you'll love it, just wonder where the costs have come from these days as this cam kit with followers, lube etc was under £100 all those years ago, oh, and you'll need an adjustable fuel pressure regulator which is very important and will help you set it up properly... enjoy, you won't regret it.

[welshpug 1,662]

a 300 degree cam can be used daily, but needs good compression and itb's, itll have a LOT of grunt all the way through the rev range.

 

you never need an adjustable fpr.

Edited July 24, 2014 by welshpug

[Mac Crash 78 1 Cars]

for genuine road use? I know nothing about ITB's but we found the throttle response/urgency with an adjustable fpr was much improved. Our CR was around 11.5:1 but then we had 5 star fuel too.