3.6 964 Project Engine - ideas wanted

[billjam]

I started out with this on the 964/993 forum but I think they are all asleep over there! Let's see if real engine builders are a bit livelier

A partly dismantled, mostly complete 1992 3.6 964 engine (type M64/01) has found its way into my garage and is about to become my next project.
I have modified and rebuilt several 3.2s and 3.3 turbos (engines and cars) but the 3.6 is new to me so I am looking for some ideas for modifying it. So far, I’m comforted by the fact that the engine itself is pretty much the same as earlier models, but where I am in new territory is with engine management, intake and fuel systems.
At present, I haven't decided what car it will end up in - that's next year's project, but I am considering a 914 (lot's of work and a bit of a challenge) or a nice mid 80's Carrera (more likely, and obviously much easier).

My aim at present is to rebuild this engine with a bit more power than standard (of course!) so that it will be suitable for street use and occasional club events. That means no over-the-top internal mods, but I am prepared to look at engine management, EFI and headers.

I am looking for ideas or best-practice directions in the following areas …
Heads
Ports look reasonably large. Is there much to be gained by porting them? This is a zero cost item because I always do this myself.
I took the heads off last night and was surprised to see that they were installed directly onto the barrels without gaskets (just like previous models). I thought there were some issues with heads on these early 964 engines leaking and it was fixed with gaskets. Maybe I wasn’t paying attention that day! Should I be looking at doing anything more than lightly remachining the head and barrel faces?

Camshafts
Which camshafts are practical alternatives to the standard 964 cams for good road performance?

Inlet manifold and blocks
The size of the phenolic blocks on 930 motors is a real constraint to inlet porting. At least the 964 blocks are larger, but there’s still not much wall thickness available for boring them out larger. What’s the usual way around this?
The manifold itself is a bit of a monstrosity. I have the aluminium version. I am prepared to consider other options if there is a reasonable benefit.

Oil cooler
This engine doesn’t have the crankcase-mounted oil cooler that I am familiar with on earlier engines but the crankcase looks like it could be drilled to accept one. Is this the case? If I fit a cooler here, I guess I would also need to modify the air ducting over the engine as well?

Exhaust
I’m open to suggestions here. I don’t know how effective the standard system is and whether there is much to be gained by using after-market headers. Ideas, opinions?

Clutch
I have the standard 964 flywheel only with its loose starter ring gear; no clutch or pressure plate. What are my options for mating up to a 915 box? Use a 3.2 clutch and flywheel complete?

Engine management and fuel injection
I don't have injectors, ECU or engine harness. A few other intake and fuel injection parts might also be missing, so even if I keep it stock I will need to spend money in that area regardless. Therefore, it might be an option to go to a new EFI system. The twin distributor looks like it has been full of water for a while and may need a bit of work and one of the fuel rails is bent, although most of the fuel hoses look OK.
Therefore, I am prepared to look at other alternatives as far as engine management and fuel injection are concerned. Are there some options that are proven to be easy to set up and tune for this engine?
I could also scrap the ugly inlet manifold and the phenolic blocks and go with ITBs with some kind of injection system. Is this done? I know it is a leap backwards as far as technology goes, but even a couple of Webers might be entertained (look good and sound nice!).

I know there’s lot’s of separate little subjects here, but each time I search on something, I get bogged down for hours reading about all sorts of interesting stuff which doesn’t actually answer my questions. I would really appreciate some responses from others who may have been faced with similar decisions in the past so I can form a general direction for this rebuild and start shopping for parts.

This is how it arrived home (in the back of son's Suzy).

[911jettat]

Rennlist has huge 964 forum, did a quick search and found these threads:

Racecar Project - Race Engine #2
Racecar Project - Race Engine #2 - Rennlist Discussion Forums

9m 4.0 litre 964/993 engine in development

http://forums.rennlist.com/rennforums/showthread.php?t=252445&referrerid=19642

964 engine upgrades
http://forums.rennlist.com/rennforums/showthread.php?t=247242&referrerid=19642

[scotsman60]

Hi Bill,


I've got the same motor.and the same basic need for ideas.

My '90 Carerra 2 is in bad shape and I'm starting to plan a substantial refurb including a complete paint job and serious ovehaul of the motor.

The motor is original, but was rebuilt by the PO to address cylinder head oil leaks. It has a couple of broken head studs right now and is leaking oil (they didnlt upgrade the heads/cylinders to address the root cause of theleak - just rebuilt as per original).

So while I'm addressing the repair issues I figured I'd see whay modest improvemnts I could make. Mostly for day to day road work but if I can ever get ANY free time I'd really like to get back onto the track too.


So basically, this message isn't of ANY use to you at all - but I will be following it, looking for ideas and sharing any ideas that I might come up with.




Doug

[e3photo]

Hey Bill,

I am in a sort of related situation. I am working on a 3.6 rebuild as well, although mine is out of a 97 993. I did a lot of reading and thinking (always dangerous) and came up with the path I am now taking. I wanted to get a little more out of the engine, without going up to 3.8.
I decided to go with RS intake valves, and RS cams and sport exhaust. I will chip the ECU and be running RS clutch with LWF.
I hope this helps in some way. The consensus from what I could find was that the larger valves and RS cams were the best bang for the buck.

Cheers,
Emerald

[camgrinder]

Originally Posted by billjam

Camshafts
Which camshafts are practical alternatives to the standard 964 cams for good road performance?

I do a version of the 993 super cup profile on the stock 964 cams. Works very well for a street driven engine. Basically I take the standard super cup profile and widen the lobe centers to 114 degrees. Its working better than the DC-20 profile in 3.6 litre engines.

[billjam]

Progress so far ...

Inlet manifold and blocks
I have decided to go with ITBs to replace the original inlet manifold. I am currently looking at using throttle bodies from Suzuki GSX1300, BMW K1200, Kawasaki ZX12 or Truimph 675 Daytona. These are crazy cheap on theebay. I will make up manifolds, linkages and filters to suit my final selection. None of this is going to happen overnight, but I'll document it and post as I go.

Heads
I hadn't considered changing valve size as Emerald has done. Might look at that, but sounds pricey. Rather spend $$ on engine management (I don't have an ECU to start with).
Haven't really formed an opinion on which way to go with head sealing. Some say stick with cylinder-to-head (as original), others want to machine haed/cylinder to use a gasket. This won't be a racing engine , so I am leaning towards just re-facing top of barrels and head face a couple of thou.
Are the head stud problems of earlier years resolved in this 1992 engine, or should I be adding Racewear studs to my shopping cart?

Camshafts
Thanks for your input John. I'll PM you for more info.

Oil cooler
I haven't been able to confirm that I can mount an earlier model oil cooler on the crankcase. It looks like it's just a matter of drilling holes in the right place and fitting a thermostat. Can someone confirm?

Exhaust
Still open to suggestions here. Don’t know how much there is to be gained by using after-market headers on this engine. To some extent, I guess it depends on what happens to induction and cams.

Engine management and fuel injection
I have found some really interesting and useful info on coil packs (coil-on-plug) systems and I am going to do this after a bit more research. Pulled one from my Toyota last night just to get a feel for how it looks/feels. This has to be the way to go
I am shopping for an engine management system that will support this, so if you have one on your shelf that you don't need anymore ...

[DW SD]

Bill,
Did you do any reading on the megasquirt pages? www.msefi.com
That computer will run your engine and more, including the Coil On Plugs (COP) ignition. I think the Porsche flywheel teeth and position sensor would have to be profiled for use in megasquirt, if you wanted to use those crank positioning inputs?

Doug

[billjam]

Thanks Doug. Yes, Megasquirt is on my list to check out, however I'm concentrating on sourcing throttle bodies and researching coil packs at present.
Only so many hours in a day!

Looked at a Triumph 675 Daytona today in a local workshop to confirm throttle bodies are sized OK and suitable. Then pulled the pin on two near new throttle bodies today on theebay (total $275 shipped to Aus!). Can't go wrong at that price, even if I change my mind when they turn up.
If I can't get injectors to suit, I'll plug or resize holes in TB and fab my own injector mounts and fuel rail.

[0396]

Pinned for some 964 / 993 education…. thanks

[Walt Fricke]

Bill

Why not keep the 964's oiling system: mount a good oil cooler up front in the center of the valence, where it will get a good flow of air (maybe purchase an aftermarket spoiler set up for this). Figure out an adapter to get oil from your tank to the engine.

But if you get desperate, I can get up off my d*** a** and measure the bolt spacing on the older style cooler. Though you are right - you'd have to backdate your engine cover. And maybe the engine oil thermostat also? Does the 964 even have one of those? I can measure the OD of the older style easily enough, as I have several spares.

Chances are pretty good that the earlier cooler will fit, since guys put the oil filter piece from 964 and 993 motors onto their earlier cased 911 race motors.

Walt Fricke

[petevb]

Originally Posted by camgrinder

I do a version of the 993 super cup profile on the stock 964 cams. Works very well for a street driven engine. Basically I take the standard super cup profile and widen the lobe centers to 114 degrees. Its working better than the DC-20 profile in 3.6 litre engines.

John's cup solid lifter cams worked very well on my 993 motor, though I think we did 113 degrees and clearanced the pistons a little.
With RS valves, VRam and 7500 rpm redline we ended with 330 hp (300 at the wheels dynojet) on race gas with an extremely wide torque curve- over 275 ft lbs from 3200 through 6200. ITBs would let you go with a bigger cam for more top end power, but piston clearance and streetability become issues.

I do like the ITB idea- VRam is very good for low end torque but a bit heavy, or there are things to recommend the '95 993 plastic intake if low end torque isn't a big deal and the ITBs prove difficult.

I'd also suggest bigger RS sized valves if budget allows- the stock 964 valves will cut power.

Exhaust- the 993 was very good, the 964 not as much. You should find a bit of power with good headers.

I'd consider building the motor to rev to 7500+. It's difficult to do on the cheap, but area under the curve is significantly improved.

[Steve@Rennsport]

Some thoughts,.....

1) Its REALLY nice to have that factory pressure-side filter mounted on the engine for protection. I've seen a lot of motor issues saved by that thing.

2) If you wish to run the engine safely to 7K+ RPM, you need better rods, rod bearings, valve springs & retainers, and a host of oiling modifications for durability.

Sounds like a fun project; good luck,.....

[billjam]

Originally Posted by Walt Fricke

Bill

Why not keep the 964's oiling system: mount a good oil cooler up front in the center of the valence, where it will get a good flow of air (maybe purchase an aftermarket spoiler set up for this). Figure out an adapter to get oil from your tank to the engine.

But if you get desperate, I can get up off my d*** a** and measure the bolt spacing on the older style cooler. Though you are right - you'd have to backdate your engine cover. And maybe the engine oil thermostat also? Does the 964 even have one of those? I can measure the OD of the older style easily enough, as I have several spares.

Chances are pretty good that the earlier cooler will fit, since guys put the oil filter piece from 964 and 993 motors onto their earlier cased 911 race motors.

Walt Fricke

Walt,
I found a couple of threads related to this. Searched "oil cooler 964 retrofit".
It seems that it is quite easy to fit an earlier 911 engine-mounted cooler and thermostat. Just need to drill a few holes. I'll also need to play with ducting airflow to the cooler, but that will involve modifying the 964 shroud rather than using the 911 version.
Because I am just building an engine at present, (with no specific car in mind) I don't want to restrict my options or be forced down the track of having to fit a front valence cooler and valance. I can still do that if I want/need to. I think the engine cooler is simple to do and not money wasted at this stage.
I have actually committed to buy a cooler from another Pelican today.

[billjam]

Originally Posted by petevb

John's cup solid lifter cams worked very well on my 993 motor, though I think we did 113 degrees and clearanced the pistons a little.
With RS valves, VRam and 7500 rpm redline we ended with 330 hp (300 at the wheels dynojet) on race gas with an extremely wide torque curve- over 275 ft lbs from 3200 through 6200. ITBs would let you go with a bigger cam for more top end power, but piston clearance and streetability become issues.

I do like the ITB idea- VRam is very good for low end torque but a bit heavy, or there are things to recommend the '95 993 plastic intake if low end torque isn't a big deal and the ITBs prove difficult.

I'd also suggest bigger RS sized valves if budget allows- the stock 964 valves will cut power.

Exhaust- the 993 was very good, the 964 not as much. You should find a bit of power with good headers.

I'd consider building the motor to rev to 7500+. It's difficult to do on the cheap, but area under the curve is significantly improved.

Pete, I am more interested in acheiving good street performance rather than outright power. And I don't want to end up with an unreasonable amout of $$ in this engine.
Headers are on my list of things to watch out for. I hadn't really given any consideration to larger valves. The standard ones looked pretty large to me!
I'd be interested in more info on the valves if you could steer me in the right direction. How much bigger are the RS valves?
I PM'd John regarding more info on his cams but he hasn't responded yet ...

[billjam]

Originally Posted by Steve@Rennsport

Some thoughts,.....

1) Its REALLY nice to have that factory pressure-side filter mounted on the engine for protection. I've seen a lot of motor issues saved by that thing.

2) If you wish to run the engine safely to 7K+ RPM, you need better rods, rod bearings, valve springs & retainers, and a host of oiling modifications for durability.

Sounds like a fun project; good luck,.....

1) Not sure what you're getting at Steve. Is the factory pressure-side filter mounted in place of the engine-mounted cooler? I don't have anything mounted there on this engine.

2) As far as building for extra revs are concerned, I am going to fit new bearings anyway - what should I be looking for in lieu of standard.
Are standard rods really that much of an issue - I thought that std rods with good bolts would be enough for up to 7500?
Oiling mods are something that I am interested in. I'll do a bit of a search on it, but if you have some pointers on most effective way to go, my ears are open.

You are right, it is a fun project. I am quite enjoying working through some of the challenges associated with ITBs and coil pack ignition at present.

[petevb]

Originally Posted by billjam

The standard ones looked pretty large to me!
I'd be interested in more info on the valves if you could steer me in the right direction. How much bigger are the RS valves?

I believe your 964 has 49mm intake and 41.5 exhaust valves. The 993 VRam got 50 and 43.5 (where some of the extra power came from) and the RS valves were 51.5 and 43.5, light weight and sodium filled I believe. I'd figure maybe 10-15 hp over what you have? Pelican sells them here, I expect you may need to pocket the 964 pistons for clearance if you go with a cup solid lifter cam (which I would highly recommend).

As Steve mentioned when I did this I paired the with springs, ti retainers, etc to get to 7500 rpm, but the fact that you're on a tight budget sounds like it rules out reving the motor that high- I agree you'd need rods, bolts, etc. Probably not worth it given what you're saying.

Originally Posted by billjam

Pete, I am more interested in acheiving good street performance rather than outright power.

Given that statement and the fact you'll be limited on revs you might consider adding a Vram intake- when you say "good street performance" that's what the VRam is designed for. If you went that way I'd guess you'd probably be up 50 ft/lbs between 3500 and 4500 rpm over the ITBs, though of course you'd loose throttle response.
I love ITBs but unless you do the pistons (for a big cam needing more clearance) and rev the motor to higher RPM I'm not sure ITBs will pay off on the street. On the other hand I'm also interested to see what you come up with for an ITB solution...

[billjam]

Camshafts
Have decided to go with John's DC21 grind. Should give extra power to 6500-ish.
Decided not to go for a higher power band as costs just become exponential to build in reliability over 7K. That's not what this engine is about.

Heads
They are in the shop for new guides at present.
Decided to stick with standard valves. RS valves are each 5% larger than std 964 valves but I think the $550 + shipping + seat machining costs could be better applied to headers where gain might be a bit more than 5%, especially with higher lift camshaft (+4% inlet lift and +9% exhaust lift). If my valves needed replacing, RS valves would be first on the shopping list - unfortunately they are good! My logic may be flawed, but it makes sense to me!
One problem I see with the exhaust ports is that there is very little room for enlargement due to the gasket ring groove. Is this groove normally welded up when bigger headers are fitted?

Head Studs
A question I asked earlier - Are the head stud problems of earlier years resolved in this 1992 engine, or should I be adding Racewear studs to my shopping cart?
Any comments?

Coil Pack Ingition
No decision here yet. Still open to practical suggestions. Currently being discussed separately at thread Audi/VW coil packs question
I still like the idea of separate coil packs (coil on plug) but open to other ideas.

Oil Cooler
A standard 911 cooler and thermostat is on its way from another Pelican.
I'll need to modify the 964 engine shroud in the region of the cooler, so I'll post some results of that modification later.

ITBs and Inlet Manifold
Still waiting for ITBs to turn up, but work has started on their manifolds.
ITBs are 44mm and manifold and ports will be same size right into head.

Clutch and Flywheel
Still looking for best way to go here.
Considering that engine will most likely be attached to a 915 box, I presume that a complete higher spec 3.2/915 clutch setup would be the easiest fit. Yes?

Engine Management
Megasquirt II seems like the only way to go!

The weekend approaches ... more parts cleaning ,

[Walt Fricke]

Bill

Have you confirmed that the engine oil thermostat from the pre-964 cars will fit and work in your later case? If I have this right, for your case Porsche dispensed with this thermostat so the pressurized oil always flowed through the filter. Since you are putting a filter on, it would benefit from the protection the thermostat gives it against overpressure when the oil is cold.

In pictures, the 964 appears to have just a cover plate with some sensors over that hole. When running an RSR system (filter, not cooler, for earlier cases) you have to install a special plug into the thermostat hole to be sure the oil always flows through the filter, and that the cold oil short cut hole is always blocked. Does the 964 case have this short cut passage permanently blocked/not cast/drilled?

Walt

[billjam]

Originally Posted by Walt Fricke

Bill

Have you confirmed that the engine oil thermostat from the pre-964 cars will fit and work in your later case? If I have this right, for your case Porsche dispensed with this thermostat so the pressurized oil always flowed through the filter. Since you are putting a filter on (BJ: I think you mean "cooler"), it would benefit from the protection the thermostat gives it against overpressure when the oil is cold.

In pictures, the 964 appears to have just a cover plate with some sensors over that hole. When running an RSR system (filter, not cooler, for earlier cases) you have to install a special plug into the thermostat hole to be sure the oil always flows through the filter, and that the cold oil short cut hole is always blocked. Does the 964 case have this short cut passage permanently blocked/not cast/drilled?

Walt

Thanks for the heads up on this. It seems that retrofitting a cooler isn't difficult - others here have done it - so I am sure I can make it work.
I don't have access to the crankcase at present to check the oil passages, however I recall noting that the casting looked the same as earlier engines but some of the passageways for the cooler and the thermostat weren't drilled through.
When I do this mod, I will document exactly what needs to be changed and post here.

[Walt Fricke]

BJ - right, cooler.

Odd how we can mistype our thoughts. Good that we can usually deduce what someone meant when they do that.

Walt