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Engine Specific Info and Questions => IDI Engine => Topic started by: Dr. Diesel on March 11, 2005, 11:01:53 pm
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So i'm in the middle of another 1.9L experimental engine build. This time, among some other things, I'm paying closer attention to the head. I have to say, the exhaust ports simply suck! I'm confident saying that there isn't a VW head out there that's nearly as bad. Needless to say, I'll be spending some time working those ports. I guess the point of this is, if you're planning to hotrod a 1.9L, prepare to spend the $ for a good port & polish job.
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What would you say the biggest problem is, are the ports simply too small, or bad casting flash? The 1.9 should flow better than the 1.6, with the slimmer valves, right?
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Not all 1.9's have the skinny stems. Only late model engines (95 and up) have 7mm stems. I would guess that they would be marginally better for flow. I would install the old style 1.9 or 1.6 dual springs if you go this route though. The newer heads with 7mm stems have single springs that I'm told aren't as good, especially if you want to rev it.
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lots of steps, ridges and sharp corners... nothing that can't be dealt with, but definitely requiring work! You can neck down valves to improve airflow
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From reading parts catalogs, I was under the impression that the 1.9 engine uses the same head as the 1.6. I guess I'm wrong here. But can a 1.6 head work with a 1.9 block? Is there a reason not to combine these? I'm just finishing my first engine rebuild -- 1.6 n/a, totally stock. But on the next one, I intend to do lots of mods. Just trying to learn as much as posssible.
BTW, where do you guys get your engine parts?
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Yes, I believe the 1.9 and 1.6 heads are interchangeable. I'm pretty sure that either head will fit on either block. Just out of curiousity, is the parts catalog you're looking at from Parts Place, in Michigan?
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The hydraulic 1.9 and 1.6 heads are very similar. They will both bolt onto either block. The 1.9 has a couple of differences. The intake ports are a different shape. A 1.6 intake manifold will bolt up but the ports won't align properly. They can be made to work with some welding and grinding. The 1.9 uses a different valve cover, held by 3 bolts down the middle rather than 8 bolts around the outside, not a big deal. 95 and up 1.9TD's have smaller valve stems and single valve springs. Older models and 1.6TD's have 8mm stems and dual valve springs. The lifters are also a different part number, though I don't know exactly why.
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86AAZ: Yes, I'm talking about the Parts Place catalog. They seem to have good prices, and they have been pretty helpful and friendly to deal with. I'd just like to know what else is out there for engine parts. I guess I'm getting off topic by asking on this thread.
So a 1.6 head will work just as well on a 1.9 block as a 1.9 head? I have most of the 1.6 parts -- manifolds, etc. So on the next one, I'd like to go with a 1.9 td block, but stick with the 1.6 top end if it's just as good performance wise. BTW I intend to do whatever head porting and polishing, and manifold mods I could.
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So a 1.6 head will work just as well on a 1.9 block as a 1.9 head?
make sure it is a 1.6 HYD head...
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Sorry to hijack, but can anyone give me the phone number to parts place? They seem to be invisible to the internet... ;)
Thanks!
Brendan
84 Scirocco 8v
00 Camaro L36 M49
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Aren't the valves bigger on 1.9l heads too? Also on the 1.9l, aren't the swirl chambers larger in diameter, and also with a larger port between swirl chamber and main combustion chamber?
In the past I have put together a "side by side" comparison of 1.6l vs 1.9l head, that was very revealing to be able to compare the two side by side. I will see if I can locate it.
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Parts Place number is 248-373-2300.
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Parts Place number is 248-373-2300.
Thanks!
Brendan
84 Scirocco 8v
00 Camaro L36 M49
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I started working on the ports of this head last night. I'm still quite astounded at just how poor they are. Big gains to be found working in them.
If you're doing a port job, don't forget that the conventional piece of gasser wisdom about NOT mirror polishing the intake ports doesn't neccessarily apply to a diesel.
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DOn't be dissapointed if you don't get the gains you expected. I always thought tHe turbo helps make up for some poor flow because you're working with a pressurized air strream instead of a vacuum like a gasser. I'm really curious.........
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there are some unfortunate ridges inside the intake port's bowl area that I'm sure will benefit the cause if they were removed. Mirror polishing's bound to help a little. But, My main concern is in the exhaust ports. There are big gains to be had in there, no question!
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How 'bout some pics? ;)
Brendan
84 Scirocco 8v
00 Camaro L36 M49
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i was thinking about it... we'll see what happens.
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i was thinking about it... we'll see what happens.
Any updates? :)