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#300
by
935racer
on 02 Aug, 2006 15:14
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I imagine any more than you are talking about would be disastrous to the compression ratio.
why? Its on the other side of closed valves....
No the modification I was mentioning is on the deck surface.
X@V, this technique does work, but will drop the compression ratio quite a bit, If you perform this modification you MUST blueprint the displacement you have added and balance them across the cylinders. Blueprint the head stock, than try this method on a core head before doing it on your good one. If you do not have too much porting experience on your hands than you can try the same shape but let it wander no further than approximately 5mm from the valve seat, I would still reccomend beveling the edge just outside the valve seat, do the complete circumference of the circle and don't let the bevel stray more than 1-2mm. Whatever measurement you decide to take off keep it the same all the way around.
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#301
by
X@V
on 02 Aug, 2006 20:21
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I understand...
Before this operation, my compression was 390, 520, 520 and 420 :?
I changed the rings and one exhaust valve (it was leaking on the 390psi cylinder). A difference of 10-20PSI between two cylinders would not make a big difference, if I compare to before.
I will do it on a old 1.6TD's head tomorrow and I will shot you the result.
Where could I send my next head to have a good job, ans maybe pre-cup coating?
Thanks
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#302
by
RabbitJockey
on 02 Aug, 2006 20:29
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935racer: look at this:
What do you think about it?
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#303
by
935racer
on 02 Aug, 2006 21:59
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I understand...
Before this operation, my compression was 390, 520, 520 and 420 :?
I changed the rings and one exhaust valve (it was leaking on the 390psi cylinder). A difference of 10-20PSI between two cylinders would not make a big difference, if I compare to before.
I will do it on a old 1.6TD's head tomorrow and I will shot you the result.
Where could I send my next head to have a good job, ans maybe pre-cup coating?
Thanks
X@V, that is really poor compression test! Obviously you want to keep it as even as possible across all 4 cylinders, just as you would with your injectors, and just as you SHOULD with the airflow, although the VW factory seems to think otherwise... Worst intake manifolds ever. Speaking of which I should have my base model intake manifolds for the 1.6td ready in a few weeks, would you be intersteed in trying one?
As far as the head go's, I can do whatever you like, however you like it, but I would reccomend staying away from coated pre chambers.
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#304
by
X@V
on 03 Aug, 2006 09:41
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For the manifold, I can't use your's because I have a VNT17 (GT1749VA) turbo.
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#305
by
veeman
on 03 Aug, 2006 13:48
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935Racer:
What sort of intakes are you guys building? I'd be interested in seeing what you've got. The stock 1.6TD intake does fine for being in limited space as it is, but you're right, it's really limited. Got any sneak-peaks?
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#306
by
935racer
on 05 Aug, 2006 22:11
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I will post some pictures on the manifolds as soon as I get my next order of head flanges in, ETA 3 weeks unfortunately. They are tubular manifolds, the economy version, which is still far better than the stocker is just a single plenum with 4 runners, pretty basic but it is miles better than the stock manifold. The race one, well I am gonna let the pictures do the talking there, but if you think the "lehman" dual plenum manifolds used by audi rally teams are something special you are in for a real treat.
All the intake manifolds will require the turbo and manifold to be mounted upside down, its the only way to get super effecient airflow to the valves. This of course is no problem with my new tubular exhaust manifolds, which feature a narrow angle merge collector, pulsed firing order, and completely equal length runners.
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#307
by
X@V
on 06 Aug, 2006 19:56
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Would you do the head porting of my 1.9TD's head if I ship it to you?
I have two 1.9TD's head here.
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#308
by
935racer
on 06 Aug, 2006 21:56
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Yes I can do the porting for you. Porting isnt cheap though, and as much as I push headporting for vw diesel, the best bang for your buck is different manifolds. Oh and if some one gives me a cad of a vnt turbo inlet I will make some vnt manifolds, I'll get some flanges cut and make some vnt only collectors.
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#309
by
X@V
on 07 Aug, 2006 09:46
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Would you like to have the VNT17 flange pictures with all the informations?
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#310
by
935racer
on 07 Aug, 2006 10:07
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Yes very much so! I'd really like to make some vnt manifolds.
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#311
by
X@V
on 07 Aug, 2006 19:03
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If you do a manifold for my turbo, I will buy one!
I will send you the informations probably wednesday (I'll be working tomorrow from 7h30am to 10h00pm)
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#312
by
935racer
on 07 Aug, 2006 21:43
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No problem, I will most definately build you a manifold
I am still waiting for some head flanges to get cut, but the sooner you get me the turbo inlet flange the less time I have to wait for those ones too.
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#313
by
theman53
on 06 Aug, 2012 14:03
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There is some interesting info here.
THIS POST IS 6 years old, so don't think I didnt know, I just wanted the young ones here to see what has been played with before.
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#314
by
RabbitJockey
on 06 Aug, 2012 19:19
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I wonder what this car would have done on a real dyno I would bet he was close to or already matching what Dave did down the road with basically the same engine but with a bigger turbo. Honestly it was absolutely huge turbo 50 trim to4e. I have one but I don't think it will ever find its way on to any of my vw diesels