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Can U Stroke a 74' 1.8 like a 2.0

I was asking alot of questions about the stroking of the 2.0 type 4 engine...I now have a 74' 1.8...complete with FI system,...and Iam guessing I can stroke it the same way,But ..are they Alum cases,..like the 2.0's..And,...also, you cant do much without changing the cam..bigger jug's....Etc correct ?? Thanks,... once again,....Frank
Old 08-06-2014, 07:34 PM
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Originally Posted by flmont View Post
I was asking alot of questions about the stroking of the 2.0 type 4 engine...I now have a 74' 1.8...complete with FI system,...and Iam guessing I can stroke it the same way,But ..are they Alum cases,..like the 2.0's..And,...also, you cant do much without changing the cam..bigger jug's....Etc correct ?? Thanks,... once again,....Frank
yes you can stroke your motor () ....but you need all the 2 litre parts to get what you need which can cost.
You could buy a 2 litre core but thats a can of worms when you open it up ????
I would personally change direction and go to a quality set of 96mm P&C's with your stock 66mm crank and you have around 1915cc and that work well in the limits of your injection system,depends on your budget afterall.
Your stock heads after a rebuild with 3 angle valve job can be cut to 96mm and will give a handy increase in power not too far from the GA spec 2 litre motor.
I don't have a lot of experience with k-jet T4 injection systems as most of my core motors are d-jet and only one k -jet (incomplete) 1.8.,apparently these are pretty much untouchable tuning wise.
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1985 944 2.7 motor,1989 VW Corrado 16v,57 project plastic speedster t4 power,1992 mk3 Golf,2005 a4 b7 qt avant 3.0 tdi,1987 mk2 Golf GTI,1973 914,2.2t to go in.
Past cars, 17 aircooled VW's and lots of BMW's
KP 13/3/1959-21/11/2014 RIP my best friend.
Old 08-07-2014, 12:42 AM
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The 914-4 cases are all the same, for all practical purposes. That means you can swap the 2.0 crank, rods, pistons, cylinders, and even heads onto your 1.8 case. The 1.8 heads will even bolt up to the 2.0 P&Cs if you want, though I'm not sure what effect that has on the compression ratio.

Note that the 2.0 crank, rods, and pistons all go together--you cannot mix and match between those and the other stock parts. The rod journals on the 2.0 crank are smaller, which means you need the 2.0 rods with a smaller big end, and the length (center of big-end bore to center of little-end bore) is different, meaning the wrist pin hole in the piston has to be a different height.

There are cranks with larger strokes available, though going much over 74mm requires a lot more work inside the case, usually including swapping over to a reduced base-circle cam among other things. With very careful work, strokes of 80mm are possible.

It is generally easier to go up on bore size, at least up to 96mm. As Mr. Tub said above, that on the stock 66mm stroke will give you a 1911cc motor, which is evidently a peppy little beast. Having 1.8 heads makes that swap easier, because you can fit decently-thick cylinder walls into the 1.8 heads--unlike the 1.7 heads, which have a smaller register where the cylinder fits into the head. The kits for the 1.7 get very thin and often have problems.

--DD
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Old 08-07-2014, 07:09 AM
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Kool,...I think I will build the 1.8 first,It seems easier or at least quicker,..is there any increase in cam size,..if I want to keep my 1.8 F.I. System,..and as always looking for more torque,..and the same FI can it be done ,...Thanks Guys,...I gotta get driving a sports car again,..Soon...!!!!
Old 08-07-2014, 04:03 PM
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Originally Posted by flmont View Post
Kool,...I think I will build the 1.8 first,It seems easier or at least quicker,..is there any increase in cam size,..if I want to keep my 1.8 F.I. System,..and as always looking for more torque,..and the same FI can it be done ,...Thanks Guys,...I gotta get driving a sports car again,..Soon...!!!!
not sure what you mean about cam size,if you don't split the case there is nothing to do, going to 96mm kit ?just make sure you get the heads done right,the heads reconditioned properly are an important issue as they are the weakest link and need to be done right.
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1985 944 2.7 motor,1989 VW Corrado 16v,57 project plastic speedster t4 power,1992 mk3 Golf,2005 a4 b7 qt avant 3.0 tdi,1987 mk2 Golf GTI,1973 914,2.2t to go in.
Past cars, 17 aircooled VW's and lots of BMW's
KP 13/3/1959-21/11/2014 RIP my best friend.

Last edited by porschetub; 08-12-2014 at 08:20 PM..
Old 08-12-2014, 08:04 PM
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the wrong cam can make the injection work poorly. If you get too aggressive in cam, the vacuum signal wont be right for the injection. I am D-jet guy, however I know that L-jet is very sensitive to vacuum leaks, and hence I assume it is sensitive to cam changes.

do not pop in a cam that is made for a carbed motor, it may not work with the injection.

I suggest you contact Elgin Cams, they are knowledgeable about this subject and may have a cam that will work. they sold me a performance cam that works well in my D-jet, but told me not to go any more aggressive if I plan on using D-jet. they should have the advice you need on cam selection for L jet.
Old 08-13-2014, 09:32 AM
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Cabinetmaker,...what is the diffrance between L-jet and D-jet,..I have a 74'1.8 but I dont know what system it is,..can you stroke the bottem end (larger crank rods and 96 MM juggs ),..bigger valves ,(A cam for FI) and still use the FI system...or does all the bottem end stuff require the Carb's,...Thanks FM
Old 08-14-2014, 07:24 PM
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The differance in the 2 systems mean little in your case but many on here have suggested mods to the d-jet that work and it appears they do, your system however is differant in the respect you have next to no tuning mods for it,the 96mm kit is a straight fit in job no mods to do ,if you want to you can split the case and go to a higher lift cam but YOUR system limits that and I don't really know of a cam for these ,maybe they are out there as cabinetmaker has suggested.....Google and then Google again,have never looked myself.
If you are changing to 96mm barrels and pistons it's pointless not to tidy up the heads,a good recon job on those will work with the bigger bore and way cheaper than splitting the case for a cam which will be limited by your injection.
A stock head can be given a good going over and realize 15% more flow without huge expense,new tapered exhaust guides and valves and you can go to 40mm inlet valves without changing seats when cut to suit.
My take on the K-jet is to get more air in and more exhaust out you need to have the throttle body bored ,heads ported or cleaned up with a better than average valve job and a good exhaust header,but thats expensive but I have no idea of your project cost outlay.
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1985 944 2.7 motor,1989 VW Corrado 16v,57 project plastic speedster t4 power,1992 mk3 Golf,2005 a4 b7 qt avant 3.0 tdi,1987 mk2 Golf GTI,1973 914,2.2t to go in.
Past cars, 17 aircooled VW's and lots of BMW's
KP 13/3/1959-21/11/2014 RIP my best friend.
Old 08-14-2014, 09:35 PM
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The 914 used two early electronic fuel injection systems. The first was called D-jetronic, which we usually shorten to D-jet. The D stands for "Druck", which is German for "Pressure". It used the pressure of the air in the manifold to figure out how much air the engine was pulling in; higher pressure means more air, and lower pressure means less air.

The device that measured this pressure is the MPS, the Manifold Pressure Sensor. It's a silvery hand-grenade looking thing on the right side of the engine bay, which has one vacuum hose and a four-wire bundle plugged into it.

D-jet was used on the 1.7 and 2.0 914s.

The other type was L-jetronic, which we shorten to L-jet. L stands for "Luft", which is German for air. This actually measured the amount of air that was getting sucked into the engine. There was an Air Flow Meter (AFM) between the air filter box and the throttle. This meter had a spring-loaded flap that was pushed open by air going into the intake. The further open it was pushed, the more air was going in. In many ways, it was a simpler system.

The 1974 1.8 liter 914 was the first car in the world to be delivered with L-jet. It went on to form the basis of most modern fuel injection systems.

Both systems were controlled by analog computers.

Both were somewhat sensitive to the cam grind. There were a number of assumptions "baked in" to the D-jet system in particular, about the relationship of manifold air pressure to engine load. Changing the cam changed that relationship in ways that were often difficult to compensate for.

An aggressive cam could actually make the flap in the L-jet meter wobble back and forth, messing up its measurement pretty thoroughly. The wobble would smooth out at higher RPMs, but getting a decent idle with a lumpy cam and L-jet was evidently very challenging.

--DD
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Old 08-14-2014, 10:57 PM
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A BIG thanks..to everyone for the info,...I think Ill just go for the Big Juggs and head work ??? the FI system should work ok with that set up right ?? Frank
Old 08-15-2014, 06:00 PM
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