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big bore on a 1.7?

Hey everyone.. looking for some opinions on whether to have a big bore kit put onto a 1.7 vs. looking for a larger motor.

what kind of HP would I be looking at with a big bore kit with a nice cam and heads?

up to what size could I reliable go from the stock 1.7?

thanks a ton.
rp

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Old 01-18-2016, 03:09 AM
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There are tons of people here that have the experience and know a lot more than me, but I'll start the responses based on what I know and have read (I'm slowly gathering the info to do it myself once I'm done hacking and welding):

Starting with the case (1.7L is just as good if not better than 2.0 for this) you've got many options. It's all about the cost, reliability, and desired use/performance. If you're looking for something reliable (not that many of us want to see many thousands of dollars and hours of work go up in smoke) then two of the most popular options are:

1. 2056 - (96mm bore/71mm stroke). This has been done many times and is proven reliable. Done correctly, this seems to be a great option that can easily get you to 125 or even 140 HP. Almost doubling your stock HP without too much risk of blowing up is attractive.

2. 2270 - (96mm bore/78.4 mm stroke). I believe this is a bit more challenging to put together to make it reliable, but will easily get you to 140+ HP.

There are other options / combinations you can find, but these are well documented/proven and apparently REALLY make a 914 come alive. Go here (Type 4 Store Engine Kits) and start saving your pennies and dimes. That's what I'm hoping to do in the not-too-distant future.

Keep in mind, however, you'll also have to give additional thought to things like additional oil cooling depending what you do and how this is set up as well as decide how you want to feed it (FI or carb). The stock D-Jet can be tuned to work with the 2056, but lots of people go carbs. At 2270 you're either going carbs or some after-market CIS.

Given that - decide how much you want to spend, how much you want to learn, and whether it makes more sense to find an option where someone's done the work for you (and hopefully done it well).

The "old pros" here can correct me if I've steered you wrong anywhere.

Last edited by beatnavy; 01-18-2016 at 05:52 AM..
Old 01-18-2016, 05:22 AM
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I think the 2056 is the way to go. Good bump in HP while remaining dependable and bullet proof without generating a ton of heat to deal with. Best bang for the buck and should you decide to sell at some point, not an engine most buyers would back away from.
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Old 01-18-2016, 05:47 AM
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Putting a 96mm P&C kit on a 1.7 (or 1.8) makes 1910cc. It can be a rev-happy little beast, if supported with the right cam and head work.

Note that the 96mm kit for the 1.7 uses cylinders that are quite thin (2mm or less) at the top. I usually recommend that people use the kit made for 1.8s, and have the heads fly-cut to fit them. The cylinders for the 1.8 have a larger outer diameter, and they are decently thick even when bored out to 96mm.

Just putting 96es on a 1.7 would probably bump the power up by ~5-10 HP and a good amount of torque, and the D-jet could be tweaked to deal with that. Going with a hotter cam means no D-jet, so you switch to carbs or an aftermarket FI system. At that point, you should be able to hit 100 HP pretty easily, and more if you put more money into the heads and get a real tuned header style exhaust.

Lots of things can influence what power level you get, though, and some of them can be fairly small details. Like a few cc of space in the combustion chambers can change your compression ratio, affecting the power level (and how likely you are to get detonation, which can blow holes in important parts). If you want significant amounts of power, you will probably have to invest some real money in the heads.

--DD
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Old 01-18-2016, 09:29 AM
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thanks everyone for your suggestions.

Dave, if I was looking to hit 140 - 150hp +, how much would nice cam/heads help out?

would you recommend starting with my existing 1.7 or trying to find a pre-built 2.x engine?

I'm looking to stay around 6 - 7k.. plus, if I can get a 5 lug conversion/brake upgrade for a little more, that would be great.

EDIT: I was being conservative at 6-7k.. but would like to max out at 10k including lug conv, brakes, and making sure electrical is all working.
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Last edited by robphelan; 01-19-2016 at 12:29 PM..
Old 01-18-2016, 05:16 PM
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I used a 96 mm piston kit on my 1.7 with fly cut heads, a cam and 40mm Webers. The engine was built at a VW shop who specialized in aircooled VW engines, mostly Type 1. (When the Porsche name isn't on the door of the shop the price goes way down.) He charged me $1700 for the job including the pistons, cam, and a 9.3:1 compression ratio set up. I've seen those ++2.0 litre engines blow up. The shop took all winter to do it. He wouldn't touch the tin but I didn't mind doing that. The result was something like 105 to 110 HP. and it had good torque and revved very quickly. Great fun.

Break it in using 15W-40 diesel engine oil plus some extra ZDDP and go for it.

Larry Steckel
Former 914 owner.

Old 01-19-2016, 05:05 AM
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