1.6L GTI Motor

Started by Angle, September 19, 2007, 07:12:27 PM

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qta4

Using the appropriate block and crank, bore to 84mm,2100cc is doable
Skill is, sucessfully tightrope walking across the Niagra Falls.
Intelligence is, having the sense not to do it.

Angle

Quote from: BB on October 11, 2007, 08:15:29 AM
My 1.6 motor was apparently nearly 2l but had the original crank. I haven't heard of any stroked ones. Johnp will have some real answers no doubt as to the max boring and stroking.

Do you have the block or any of the original pistons still in your possession? I haven't been able to track down information on recommended bore sizes for the 1.6L block, so I'd like to know if your block was originally a 1.8L block, bored to 2.0L or the 1.6L block. And knowing the piston and bore size would be helpful as well.

I've sent an e-mail to Bildon to see what advice they offer. Greg Raven's book is on back order so I don't expect to see it for another month.

dubstar

I have the Raven book at home.  Would you like to borrow it?  Shoot me your address and I'll post it to you 
"I am so clever that sometimes I don't understand a single word of what I am saying."

Angle

#23
Quote from: vwrally on September 20, 2007, 12:51:45 PM
What do yopu want to do with the car you can make a very good motor using the 1.6 with standard valves and near standard ports.

Just bump the compression and tidy the first 50mm behind the valve face, everything does need to be balanced etc to get the most from them but they make a very good motor. They love compression and in full race trim run as much as 14:1 I would settle for 11:1 and you should still be able to use pump gas if everything is done well.

I do have some stuff on these motors somewhere but they are a bit hard to get bits for now especially true high performance parts. I will tyry to find my bits and pieces to send to you

I would consider putting the motor in a box in the corner and doing the 2ltr conversion, much cheaper and easier to get bits for.

Can you elaborate on your comment "they make a very good motor"?

johnp

Quote from: AngleBox on October 10, 2007, 10:48:59 PM
Thank you. That was question was aimed more towards understanding how big an over-bore the block will take. Can the 1.6L motor be stroked as well?

It is not the block to use for over boring.
82.5mm is the max you can go, but NOT reccomended as the walls get very thin.
Use a later 1.8 block, then you will have no problems.
You can use the crank from the 1.7, it is 86.4mm and has the same big end journal and rod size as the 1.6 GTI engine.
I do not know how you would get on with pistons tho, I presume you are wanting to stick with the Heron head?
I do not know of any pistons out there that would work with the stroke and Heron head combo.
If you used the GTI pistons you could machine the top of them to compensate for the increase in stroke, but your compression ratio would be VERY high, to high for any pump gas.

Angle

#25
That is the feedback I got from Bildon, now coupled with your comments, I understand his point. Essentially he said he didn't know of a piston that would work with a stroked motor, but as I was inquiring re: stroking and over-boring I missed his point in his response.

Assumming the use of 80.5mm forged piston (raising CR to 11.6:1), with an appropriate overbore to match, balanced and blueprinted engine, and replace with lightened rods, could I expect to be able to safely raise the max RPM, or would that require replacedment of the crank as well? (making a further assummption that BB's head will flow sufficiently). The main attraction for me to the Heron engine is solely on the basis of being able to have an engine which happily revs its guts out and is smooth, two things which I understand are characteristics of the Heron motor.

And the more pivotal question: Is there likely to be any HP benefit in using a Heron Head & 'heavy' Heron Piston with an overbored 1.7L block or is your opinion that the decision is more fundamental; use 1.6L 'as is' or move on? It may be feasible to have someone make an appropriate piston, but that may not be worth exploring.

vwrally

Quote from: AngleBox on October 11, 2007, 01:55:46 PM
Can you elaborate on your comment "they make a very good motor"?

We have a production racing 1.6 motor that has very light head work but is fully balanced and blue printed.

For a 1600 sohc non crossflow std cam motor it is very impressive, heaps of torque and on the track not a lot slower than our 1.8 high hp motor (much better torque). This has high compression thanks to using stad Audi 5 cylinder pistons machined down to suit.

The 1.8 high hp motor uses a diesel crank and a heron head ported to maximum possible in places and using 40.5 and 35mm Valves and a 1.6 block

Angle

#27
Quote from: vwrally on October 12, 2007, 09:49:06 AM
We have a production racing 1.6 motor that has very light head work but is fully balanced and blue printed.

For a 1600 sohc non crossflow std cam motor it is very impressive, heaps of torque and on the track not a lot slower than our 1.8 high hp motor (much better torque). This has high compression thanks to using stad Audi 5 cylinder pistons machined down to suit.

The 1.8 high hp motor uses a diesel crank and a heron head ported to maximum possible in places and using 40.5 and 35mm Valves and a 1.6 block

What compression are you at with the 1.8? And your comment 'much better torque' applies to the 1.6? What cam's are available for the Heron head, and from where? I feel like a school kid asking all these questions.

BB

Yea if gets pretty frothy in here when these old mk1 masters start really filling you in on all the gospel. I love it.
My motor had a 1.6 audi 80 block(Did, Now is simply a standard gti 1.6 block), heron head, big inlet valves, Cam with vernier pully, otternger as the car had a sticker on the back.
It was bored block to max, I couldn't get it oversized again.
And it had a standard crank and rods but Ross racing pistons. Which were rooted, it had been in the hands of idiots had a broken rad outlet that was fixed with a beer can and had a totally cooked and smeared motor. Must have almost seized. A few times. I fixed the head gasket at first and put a Rad in it new plugs and oil and it started with a blur of revs and horrendous mechanical noise from the head . I thought oh my god ::) But it setteled into a nice lumpy idle and warmed up and kept running with oil light out and getting smoother as it warmed up ;D I drove it for years and it didnt blow smoke, i really only took it apart because i thought i didnt wanna wreak it but it already was.
Went amazingly, for a year and the noise is just a high lift cam banging away on worn old valve giudes and stuff but yea i was impressed.
I stoopidly threw the pistons as they were worthless ............except to mesure. But surely if you ring Ross racing they will tell you what they sell.
The end is nigh, but the end of what is the question?

vwrally

Quote from: AngleBox on October 12, 2007, 10:22:18 AM
What compression are you at with the 1.8? And your comment 'much better torque' applies to the 1.6? What cam's are available for the Heron head, and from where? I feel like a school kid asking all these questions.

No idea what the compression is sorry.
Any mechanical head cam for an 1800 will also work in the heron head, you do need to make sre there is enough room for the cam to rotate without hitting the head, I jest clearance the head with the mighty Dremel. The good head we have uses  Alfa cam buckets instead of std. they have the advantage that the shim is under the bucket and therefore cant be flung out. This can happen if you have an agressive cam


Angle

Thanks for the heads up on the cam. I was concerned that as an interference engine, the cam choice may have been limited. Also, is there any need to slightly overbore the engine to allow for greater gap between the piston and cylinder wall?

BB - Is the original cam still in your head?

BB

Its still got the ottenger cam. The head is the good, and fully recoed except no new valves. bit now the block is just a good 1.6 standard block pistons and crank, but new rings and bearings honed and new gaskets and oil seals. Goes good, only problem was one valve the clearence closed up so i got the shim ground down, seems fine now but somebody said the valve might be mushrooming inside out and the head could drop off :P So i would get that valve replaced, maybe four new exhaust valves or whatever it needs, it was the valve closest to the cam sproket end on no 1 piston, exhaust eh.
The end is nigh, but the end of what is the question?

Angle

I hear valves are hard to come by. I'll get back to you on that... I read somewhere you can fit nissan (?) valves but you've got to machine them.

qta4

Quote from: vwrally on October 12, 2007, 09:49:06 AM

The 1.8 high hp motor uses a diesel crank and a heron head ported to maximum possible in places and using 40.5 and 35mm Valves and a 1.6 block

How did you fit the 40.5mm inlet and 35mm valves in a Heron head, my measurements including overlapping valve inserts runs out of room?
Skill is, sucessfully tightrope walking across the Niagra Falls.
Intelligence is, having the sense not to do it.

Angle

This excerpt from a German DIESEL book, is contrary to what I had understood re: diesel vs gas crank in the VW 1.6L engine:

The 1.5l 50 BHP Diesel and the 1.6l 110 BHP spark ignition engine use the same internal engine components (crankshaft, pistons, conrods and bearings).

Another text indicated the crank is forged in the GTI motor.

Angle

Quote from: qta4 on October 12, 2007, 09:13:05 PM
How did you fit the 40.5mm inlet and 35mm valves in a Heron head, my measurements including overlapping valve inserts runs out of room?

I want your books! I have found the investigation of the Heron head engine very frustrating. In comparison, finding out everything you want to know about Ford's crossflow motor is straightforward.

Angle

Another question. Is this principal relevant to the gas engine?

quench is the space between the top of the piston and those flat portions of the head which overhang the cylinder bore and correspond to flat sections of the piston crown. The TD head is essentially flat over the bore, except where the valves intrude. Likewise, the top of the piston is essentially flat except for the "swirl pots". Ideally, these corresponding flat sections would have very little (less than 10-thou) clearance between them at TDC. By very nearly closing they force the air that would normally be trapped out on the edges of the piston and head to squirt violently into the swirl pots, creating turbulence and adding oxygen to the mix. The result is more power and torque, along with reduced smoke and other emissions. The precise top of the pistons determines which gasket to use to ensure proper static and dynamic quench (normal practice is to provide about 40-thou of static quench -- the rod and piston grow about 30-thou under high RPMs, producing the proper 10-thou of "dynamic" quench).

qta4

#37
The combustion chamber shape is a science re-gasoline engines.
The squish area of a cylinder will have many experts give many and varied examples of works and does not.
Many years ago we build a V6 ford engine with almost no combustion chamber and technically poor but large squish area.
The engine performed amazingly well .but power was apparent only after we advanced dynamic ignition advance over 33 deg.
The combustion chamber regulates the area and time fuel has to burn.
large squish area (unconfined area) requires more time for fuel to complete combustion , hence large ignition advance to produce power.
Not the ideal.
The Heron head was essentially a head with squish area only in the piston,works better with really high compression,because of a smaller squish area.

I dont know of any modern engine manufacturer that uses heron type heads, maybe nothing to do with performance, probably emmisions
Skill is, sucessfully tightrope walking across the Niagra Falls.
Intelligence is, having the sense not to do it.

Angle

Don't you mean larger squish area? Wouldn't any area not contained within the 'bowl' or 'swirl pot' of the piston be disignated squish, requiring a high compression in order to force the 'fluid' into the combustion chamber contained in the piston? Wherease with a concave head, the squish area is reduced as a result of the combustion chamber occupying nearly the full cylinder bore, meaning efficient combustion can be had utilising lower compression?

My logic is pieced together, but that's how I see it at the moment.

Angle

More random internet "knowledge". Care to validate?

The Heron Head 1.6l 8v...110hp in stock form with 180hp in race version.