Hello. I am planning on enlarging my engine and would appreciate your opinion regarding my plans.

I have a 1.7 liter that has a big bore kit enlarging it to 1.9 liter. It is in need of rebuilding. My car will be used as a daily driver. I want all the power to be concentrated at the low RPM range. I want it to be easy to use for casual driving.

Rods: I will use 71mm rods from the 2.0-liter engine.

Crankshaft: I understand the crankshaft must also be machined to accommodate the 71mm rods. Am I correct on this?

Piston/cylinders: I plan to use a 104mm kit from AA Performance that would increase the displacement to 2.4 liter. I understand I will need to machine work the case and heads to accommodate the larger cylinders. These are not forged pistons which have piston slap. Forged is great for racing where the engine is driven hard and frequently rebuilt. This engine will see light duty. Comments?

Camshaft: I plan to use a Web cam from AA Performance. It is WC-00-152. This is described on the website as “Good overall performance for carbureted mechanical street engines. The perfect street cam! RPM range 2500-5500. .423/.423 Lift, 270°/270° Duration, 234°/234° Duration .@ .050 Grind #86”. I very much would appreciate comments on this? What is meant by “mechanical” street engines? Is this referring to solid lifters? There are camshafts listed on Pelican Parts but there is no verbal description for them. For all I know, I could be ordering a stock cam with no overlap.

Lifters: I plan to use stock solid lifters.

Camshaft gear: Is a new camshaft gear needed? Why are they aluminum? Are they intended to wear instead of the crankshaft gear?

Distributor: I do not know what distributor I will be using, but I want one with vacuum advance and a solid-state circuit. I know of a Pertronics distributor advertised for the Type 4 engine. Comments?

Clutch: I have a stock clutch and plan to continue using it. A heavy clutch makes a daily driver uncomfortable.

Starter: My current starter is a high RPM gear reduction starter. I plan to continue using it.

Carburetors: I currently have 44IDF carburetors and plan to continue to use them. Should I consider changing to 48IDF carburetors sometime after the rebuild?

I know these are a lot of questions but any comments would be appreciated.

Thank you.

Send a PM to Mark Henry and do what ever he says.......

Budget? Won't be cheap. Read this site thoroughly and go in eyes wide open.

Also look at Raby site and digest what he's doing, why, and how much those engines cost to deliver reliability at those displacments.

Budget in case machine work. The stock heat exchangers may not support the displacement, so you may need to go to headers. What do you plan to use for heads? Do your homework before you leap.

One of the largest problems when you go larger is fuel control if you stay injected. So the details can add up quickly.

I've got a 2316 with carbs, and it's fast as hell, but I wouldn't say it's "easy" to drive. I'd love to set it up with FI to add some easiness.

A top 911 engine builder told me it’s more important to build a good engine than to build a big engine.

I agree. That is why I would like to hear from others, especially those who have done this. I can stay at 1.9 liter and the adding of a cam made for carburetors and vacuum advance distributor may be the best choice.
Since I will be mostly going on casual drives in the countryside, the stress on the engine will only be occasional. What size are most people's cars?

Does it have a racing cam? They tend to have low power at low rpm and then the power suddenly comes on at a higher rpm.

What carbs do you have on it?

See post #2 so this thread won’t drag on.......

You are not going to want the cast iron cylinders for a displacement that large. You will heat soak very quickly and have cooling issues. Not a problem if you are only doing short drives, but will make long trips no fun or make for a short lived engine. Nikkis. ARP bolts. Talk to people that KNOW T4 heads about your plans and bring money.

Bigger engines need a lot more then stock/2056 motors to keep them cool. Hot engines don't last long.

I love BIG engine builds. But I have also seen big engine builds that make less power then a well built 2056 or 2270 (96mm pistons, stoker crank). And I've seen big engines that make a ot of power and are also grenades. To do it right takes money and and a good amount of planning. I don't see you being happy with the cast AA cylinders - and changing the cylinders forces other expensive changes. And plan on most of your money going into heads.

Zach

Budget?
You can make reliable HP, but it costs a lot to make it reliable.
With an engine that has to be depended on as a daily driver you have to focus on the reliable point.

I won't build an engine with bigger than 96mm iron cylinders, for bigger you need the Benjamin's to pony up for Nickies. For 96mm I like the KB pistons from EMW.

#86 is a smaller cam, originally for budgets that can't afford a lot of headwork. Close to a Scat c-25 but a bit better.
Type one 26mm pump and steel cover.
New gear is needed as it's clearanced and modified for the bolt on cam.
Get a 123 or find a Mallory dizzy, with big carbs/cam just get a manual advance.
The 44mm Webers you have are a bit big for a 2056cc but can work OK.






If this is your first build I'd focus on a smaller 2056 (71X96mm) engine.

The 2056 is a great package,with the right cam and some headwork they will drive well and make power,as mentioned 44mm carbs are too big but could be "choked "back with smaller vents ,I cant remember off hand but think the smallest ones for them are 32mm.
Good luck.

Thanks a lot for the help. I did not know what EMW stood for so I did a search and discovered it stands for European Motor Works. I remember a friend of mine referring to them. Since I am in the same general area (Palmdale, CA) I will probably get my parts from them and rely on their advice. I have rebuilt three engines before (Corvair and Opel GT) but none have been Type 4.

Thanks for all the help guys. I will probably go with the 2056. It will still be an increase in displacement over the 1910, the cam upgrade will help too, and the rebuild will be much simpler.

Thanks again to everyone.

So again - why are you going to tear down the 1911? If the 1911 makes good compression and does not have leakdown issues, you probably just need to tune it. A 914 with a 1911 engine should SCOOT! Even a mild 1911 should make 110-115HP. It should be more rev-happy then a 2056, but should still have a better bottom end power then a stock motor. It should be more then acceptable for the driving you are describing.

If you just crack open the case and change the crank to a 2.0 crank (and that's all you need to do to get the engine to a 2056 in terms of displacement) you're going to be unhappy that the results are not that different then the 1911. For a basic build, the difference in power between the 2 engines is less then 10HP. Unless your engine is actually worn out, I suspect your issues are carb tuning and can be fixed without a rebuild. The 44IDF carbs you are using are way too big for it and will push all the power into the top end of the engine.

Before you go any further, please do the following:
1) basic tuneup (valve adjustment, timing/dwell adjustment)
2) compression test (hot engine, all plugs out, throttle wide open). POST YOUR NUMBERS
3) Leakdown test (not as important as the compression test - but a engine making decent compression can still have poor leakdown - mine did) Again POST YOUR NUMBERS

You need to do these tasks with the new engine anyway, so getting your baseline now will only help you. Plus you will have a baseline to judge improvement. And maybe you find you just need some tuning.

If those three tests are promising your issue with drivability is tuning.
1) If you are going to stay with carbs, change your 44IDFs for a set of 40IDF or 40Dellortos. The carbs are too big and you are not going to get power until the top end of your rev range. Even if you go to a 2056, you are going to want the smaller carbs. I know this from experience. With my 2056, all of my power was 4000 rpm and above until I went down to the 40s. It was a fun, push you back in your seat a bit of a rush, but a street engine with all the power so far up the power band isn't fun to drive.

I just hate to see you spend $5K+ for 10hp when what you needed was a smaller pair of carbs and a valve adjustment.

Zach

32mm venturi and appropriate jetting.

I am not rebuilding the engine for more power. It already has very good power. I am doing this because it has a mechanical noise coming from it while running. Also, when it is cranked, sometimes there is one or two very loud bang noises from the engine. I am afraid what will be found when opened.

But since it must be torn down, the most important change, besides the repair, is installing a mild cam made for carbs, with some valve overlap.

I am doing the displacement enlargement only because it is has to be torn down anyway. Otherwise I would not be making displacement changes.

P. S. As a side note, I put the BMW brake calipers on it and it is true: they do make a very good improvement in stopping power.

Air cooled engines are very noisy compared to WC engines, lots of valve train clatter.
Do a valve adjustment before anything else.

If you use KB pistons they rattle till they get some heat into them. About 2-4 minutes or miles.

Having driven both engines in a 914...I'd take the shorter stroke for the trade off.

My quess is that the rings are done from overfueled or wrong size idle jets or mains along with a stock cam.

I'd rebuild it and use L-jet for fuel. One of the quickest 914 I've driven was a 1911 injected engine.