Porsche 914/6 911T engine rebuild

[stv951]

Hello all,

I am rebuilding a 914/6 911T engine to install on a 914.4

I am considering changing the oil pump. What would you guys suggest as an upgrade ? Should I go for a 964 pump or 911 3,2 or stock ?

Other nice mods on valves cams exhaust in order to get a little more power ?
I dont want something radical, as the car is for daily street driving and occassional mountain roads.

Suggestions would be greatly appreciated.

Thanx
Steve

[Carbster09]

Hi,

I have a 6, modded by the previous owner. It runs pretty well. So, one question, how much money do you want to spend. It gets pricey!

I have:

- 2.7 crank
- 2.2 barrels and heads
- Cam? - Web Cam, between an E and a S .. I think
- Webers, of course
- Ported heads
- Performance vlv springs w Ti retainers

Its a nice engine but no killer. Still suits your needs and its somewhat basic.

[stv951]

Thanks.

which oil pump do you use ?

[The cap'n]

Originally Posted by stv951

Hello all,

I am rebuilding a 914/6 911T engine to install on a 914.4

I am considering changing the oil pump. What would you guys suggest as an upgrade ? Should I go for a 964 pump or 911 3,2 or stock ?

Other nice mods on valves cams exhaust in order to get a little more power ?
I dont want something radical, as the car is for daily street driving and occassional mountain roads.

Suggestions would be greatly appreciated.

Thanx
Steve

911 oil pumps rarely need replacement. What evidence leads you to believe yours needs replacement? 911T cams are suited to the engine. More aggressive camshafts require a higher compression ratio to take advantage of their characteristics. Think of the engine as a package deal. Generally, any change you make is gonna require other changes to get the desired results.

The Cap'n

The Cap'n

[stv951]

Main reason to change this is that it is 45 years old and that i dont really trust it.

Should one go for a 3,2 Carrera or later 964 oil pump ?

I am planning to change the intermediate shaft as well

[The cap'n]

Not a very good reason, and not fact based. The oil pump in my engine is nearly 50 years old and is just fine. I can think of a lot better ways to spend a grand, and that doesn't include the new sump plate or the intermediate shaft.

The Cap'n

[stv951]

Still havent got a response on which oil pump to use.

Any ideas ?

[Dave at Pelican Parts]

The Cap'n's suggestion is:

Use the stock one!

There's a tech question in the most recent issue of Panorama about a 3.2 oil pump in an early 911 engine. The expert's response is "I've never bothered, and am not sure what hassles you might run into because of the different layout of the sump and pickup and drain. If you want to, try it and see how it does!"

In other words: The stock pump is quite sufficient. No need to "upgrade" to the later parts.

Also note that with some combinations of pump/pickup/sump/drain, you wind up with a pump that sucks more air than oil, leading to engine failure pretty quickly.

--DD

[Steam Driver]

If you want to keep it simple (your overhaul) keep it stock as possible. Any changes in cams, compression ratio, etc. will affect the carburetion then you can have fun sorting out the carburetion (jets, emulsion tubes, etc.). I went this route with a 914-6 engine long ago. Jerry Woods mildest cams, 911E pistons & barrels, factory sport muffler. Sounds(good on paper but it took awhile to get the carburetion sorted and because of the shift I. Power band wasn't as much fun to drive as before.

Would have been worse than that ( drive ability) if I hadn't changed the gearbox at the same time to be like an early 911. (A, M, S, E, X or something like that). Shorter ratios.

[porschetub]

Originally Posted by stv951

Still havent got a response on which oil pump to use.

Any ideas ?

Hold up and listen to what you are being told ,these replies are based on expert advise on what you NEED to do,these pumps are robust and have had filtered oil run thru them for years,best not to over- complicate what works.
The only reason to change a pump is a known engine failure or poor oil pressure when warm.
Good luck with your project,cheers.

[Jack Stands]

About the only advice may be to add piston squirters to lower the piston temps. Also, be sure to measure the piston's ring lands and cylinders carefully as they are getting old and may need replacement ($$$$). You may also want to check the information in Bruce Anderson's book on any other options for a short stroke engine.

Let us know how your rebuild proceeds as you don't hear much about 2.0 liter rebuilds these days.

[Dave at Pelican Parts]

A displacement bump could be nice. I don't recall which combinations fit easily in the 2.0 case, but I would be surprised if you couldn't get up to 2.2 liters pretty easily. Yeah, a quick look at Mr. Google says that the stroke was left at 66mm, and the bore upped from 80mm to 84mm when they went to the 2.2 engine.

"E" cams have always been a popular choice for small-displacement engines. They give more power than the "T" cams but were not as "peaky" as the "S" cams. Of course, you have to make sure the valve sizes and ports and such all work with your choice of cam... But you could do worse than to match the 2.2 E specs.

You can go larger, but more work is involved. At the very least, the crank and rods would need to be swapped out. And of course, more power means more heat to deal with.

Alternately, you can store the original engine and swap in something later and larger. If I were able to snap my fingers and have the work all done for me, I'd give serious consideration to swapping a 3.2L (complete with Motronic FI!) into my car.

--DD

[puffinator]

I have a 914-6 with original case, with '72 steel cylinders bored out to 85mm, Solex cams, JE pistons, '75 heads oil squirters, etc and love it.

[stv951]

Dear All,

I would first of like like to thank you for your responses and suggestions. Its been very helpful to read these as always.

I am building a 914/6 engine that was given to me in pieces and in really bad condition.
I am installing brand new 2,0 T pistons and cylinders into it and wouldnt want to risk having inadequate lubrication.

I am gonna change the oil pump anyway because I dont want to risk using the old one that was left for many years outside in the rain.

My initial question was if it would be better (since I will spend money on it) to buy the stock one or a 3,2 or 3,6 and then modify the IMS.

I have already ordered a new one (2.0T) after reading this thread.

That engine will go on a 914/4 that I am converting to GT look and 6 cyl.
If anyone is interested i can post pix later

Thanks again to all of you

[The cap'n]

"I dont want to risk using the old one that was left for many years outside in the rain"? Yet another case of revealing important information late in the discussion. Why didn't you tell us this before? Is the pump corroded? Is it rusty inside? If so, then maybe a good used pump from a trusted source might be in order. I sure wouldn't spend the money on a newer pump with all the bother of mods, known or as yet unknown.

The Cap'n

[Steam Driver]

Just out of curiosity since I used to own a 914-6, what is the engine number on that case?

[Peterfrans]

if you upgrade to a later pump, you probably also need to do the oil-bypass modification on your case. I don't see why you would need to modify the IMS, unless you are just refering to the shorter shaft that goes between the bigger pumps and the IMS.

The 77 and later oilpumps, identified by four ribs at the side are considered an upgrade. You can go bigger, but then also the bearing webs in the case need to be machined to accept the pump. Using a pump with a dish (carrera) instead of a pickup pipe will necessitate a different sump plate. There are nice aftermarket plates for that.

I used a 996 pump on my 1973t, probably overkill and if asked why, my answer is "because I can"

[Matt Monson]

Get a blueprinted oil pump from Ollie's along with the oil bypass mod.

[larrym]

Originally Posted by Peterfrans

if you upgrade to a later pump, you probably also need to do the oil-bypass modification on your case.

The 77 and later oilpumps, identified by four ribs at the side are considered an upgrade.

X2 - Bruce Anderson's book should be on your bench - this is exactly his recommendation

.

[porschetub]

Originally Posted by Steam Driver

Just out of curiosity since I used to own a 914-6, what is the engine number on that case?

Bingo,no answer not sure about this one ,it worries me that a motor stored outside with water damage would be worth even using sorry but not the only one thinking this, shame cause this engine maybe parts only @ best.