3.6L rebuild options
 

OK, time to start firming up some ideas and direction for my next project. I had been looking for a high mileage 993 without luck, so when I ran across a deal on a 3.6, I jumped on it. The engine came out of a 97 C2S with 70k on it. I bought it as a long block with extras. It came with varioram, fuel rails, full exhaust (- one muffler) and a couple of flywheels and plates and two boxes of misc.
I want to tear it all the way down and build it back, tweaking where I can. I have read everything I can find and it seems most don't consider going to 3.8 is cost effective. This engine will eventually end up in a 993 daily driver, maybe an occasional DE, so 3.8 would probably be overkill for me.
There just seems like there ought to be a sweet spot between stock and 3.8. I know you can get a lot of bang from a chip and sport muffler, but what else?ss cams? Can the varioram be ported any, sort of a mild approach to what 9m does?
I am basically hoping to get enough input to create a recipe for the motor.I will probably cross post because RL has the greatest 993 following, and Pelican has a higher number of engine rebuild participants.
Let's build an engine.SmileWavyhttp://forums.pelicanparts.com/uploa...1250958774.jpg

I bought a 93 3.6l motor that ended up having a broken piston ring. I wonder the same thing? Is there anything one do while rebuilding the motor to get a little more power, without braking the bank?

The only inexpensive things I have really seen so far is upgrading to Ti valve springs, chip, exhaust, RS pulley,

The 993 motor has a better designed crank that doesn't need a balancer, so your ahead of me there.

Someone is gonna say it so I will just say it right now. Twin turbo would get you plenty of Hp.

Check this out -----> http://forums.pelicanparts.com/porsche-911-used-parts-sale-wanted/492136-fs-brand-new-tt-converion-ttp-germany.html

Hey NoEardGoat,
that would be quite the setup. I think I am going to stick with the non turbo route.

I had a reply from Steve Weiner on another forum and he said...

"I can tell you without question that a properly built 3.6 with RS cams, RS intake valves, good software and exhaust will make 305-310 BHP (more with a race exhaust). With the RS LWF kit and close-ratio gears, that makes a VERY potent package. "

I think this is the path I am headed down. I think you are right in that I have it easier with the 993 engine, and I have the varioram. Are you thinking of varioram upgrade, or PMOs, or stock fuel injection? Good luck with it and keep me posted on your path.

Cheers,
Emerald

I would suggest going ITB's with standalone engine management and better cams (RS maybe) together with some exhaust mods. That will get you great power with absolutely best throttle response.

Unfortunately I have to keep costs to a minimum so I plan on leaving the bottom end alone, having the head redone, putting it back together, and just running the stock 964 injection. I need to have the heads done so I maybe upgrading some parts in there. I have some bad spots on the cams so they will need to be refreshed, but I live in CA so I don't think I can run RS profile cams and still have a shot a passing smog. For exhaust I have a set of 993 HE that I cut the flanges off to flip around. For now I need to work on wiring and fuel line setup so its ready to go when the motor gets done. Not really looking forward to it...

FWIW,..Ti is ONLY used for the valve spring retainers, NOT the springs (thankfully).

The RSR's used the stronger 964 crank as it has more rod bearing area for durability at high RPM. :) The 993 cranks are OK, but not the preferred item for engines that will see north of 7K.

If you want to gain hp, then changing injectors to bigger ones is A MUST on 964 as those are barely adequate even for stock power (250 hp).

And going programmable EFI on 964 is not as hard as it may look. Check this thread: http://forums.pelicanparts.com/porsche-911-used-parts-sale-wanted/488968-fs-vems-pnp-motronic-964-a.html

Do you have a suggestion for injectors? I still need to be able to throw the computer in a MAP that can pass CA smog req's. what about cam uprades?

It depends on the power goals you have. Roughly the required injector size in cc is the number of hp you want. Like if you want 300hp, then 300cc injectors are minimum. Stock 964 injectors are 220cc IIRC but 964 has higher base pressure than 3bar (it was 3,8 IIRC), that's why it gets away with these minuscule injectors, but it's barely adequate with stock power.

If you look for injectors, avoid ancient EV1-type crap (the ones that look like stock fat-type injectors) because the have poor response and atomization. Prefer newer, pencil-style injectors, they are directly swappable with the old ones.

They look like this:
http://www.injectorwhse.com/catalog/52-12167.jpg

With properly tuned standalone, modified cars pass smog tests easily assuming the cats are still present and sometimes even without it (depends on lot of things).

Just a thought - I know you have your sights set on a motor project --- but! The Varioram in stock configuration produced 282 hp. If you have a brain than can change a chip or have your dme re flashed then in stock configuration 300 hp is not a difficult task. If the engine does not need a rebuild - then do not do it. PMO's, ITB - RSR intakes - anthing else that you plan in your project will quickly turn it into mega bucks and the slippery slope begins. You have enough dollars to spend just to put your engine back into a complete form. Do you have a 97 or 98 brain? How much of your Varioram is missing? - Prices for PMO's are not cheap, and then you need crankfire ignition or some other method to fire your twin plug engine. Jim

Great advice from Jim D,...:) :)

Beyond an ECU upgrade, I'd spend the money on close-ratio gears,........:)

Thanks for the great input Jim. I do not have a brain yet:eek:, as I only have the engine. I guess I could wait till I find a car, and maybe look for a specific year. I am going to do a leak down per Steve's suggestion, and then go from there. I do not know the history of the engine except it has 70k and is relatively clean. I just want to make sure that once it is put in a car, it will be a reliable daily driver. I am not sure, but I think I have a pretty complete Varioram. I am missing the distributor and alternator/fan assembly.
Thanks again for the input.It is always good to have a different perspective.

Cheers,
Emerald

Steve,
When the factory used the 964 crank, did they run a special harmonic balancer? Or leave it off? Patrick Motorsports claims no reported crank breakages with the use of their crankpulley for eliminating the harmonic balancer.

Emerald,
I'd keep things very simple and advocate not spending additional $ where they may be unnecessary. Chip and exhaust should put things into a nice power range.

You could consider use of the earlier 964 cams along with a cam upgrade, which wouldn't be terribly expensive. I use a 993 supersport grind which has a nice flat curve, but seems to offer improvment. Maybe the solid lifter can follow a more aggressive profile than the hydraulic lifter?

Email me and I'll send you back the dyno #s for my setup (3.6, '95 non vram intake and engine management).

Doug

Doug,

The factory used a simple pulley; plain sheave and later, multi-ribbed for durability.

No additional balancer was used. The Patrick pulleys are OK, but a bit small so we make a larger one that maintains fan speed and cooling.

Well I did my first leak down test. Did it several times, because it is not that intuitive. I used the tester from harbor freight. I think I have 10% on 1 and about 20% on the rest. I can hear the air escaping past the valves. intake on 3 - exhaust on 4,5 & 2 and intake and exhaust on 1 & 3. Does this sound about right? Anybody have a set routine they like when using the harbor freight gauges?

Cheers,
Emerald

I also did not hear any air escaping thru the oil filler, which is good. I guess next I will start breaking it down, and send the heads to Steve for some work. I guess next will be inspecting P/C's and rings and such.

Cheers,
Emerald

I say toss a mountain of money at it :cool:

Get ITB's, and then mount the vario ram plenum on top of them.....I suppose you could use the stock DME and have a chip burned to suit...

so many different paths..

well that's my plan for an engine I'm building right now... but smaller displacement..

Sorry for the dust in your face, but did OP get that motor built? I ask cuz I'm looking at '95 3.6L with 120k miles as a candidate for rebuild....

Are the 1995 brains flashable at all or will I need a later model ECU that's programmable?

Thanks,
Rick C.

The '95s have a user replaceable chip

Thanks Bill!

If the holes are within spec I'd look at honing them and replacing all bearings and these upgrades:

High Comp Pistons
hotter cams
ported heads with new valves, seals, springs & seats
larger injectors
race exhaust...no emissions testing here in FL:D
new chip

Will this cost a fortune or is it a worthwhile project? Please let me know whattcha think the resulting Hp & Torque I could expect with these mods.

Thanks,
RC

JE offers 11.5:1 & 12.5:1 slugs for $1100

274636 Product Detail Information - JE Pistons

Is there any good reason(s) not to go with 12.5 for a mostly street build if it will run on 93 octane pump gas?

I found them on Pelican: http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=JE-274636&catalog_description=JE%20Pistons%2C%20Set%2 0of%206%2C%203.6L%2C%20100mm%20bore%2C%2012.5%3A1% 20comp%2C%20%20911%20%281990-98%29

OS Valves

Looks like RS valves are 51.5mm or 1.5mm larger then stock which are 50mm and cutting a bigger hole should be a big deal since new seats are needed anyways:
Pelican Parts - Product Information: 993-105-409-42-M154

Cams

Looks like Webcams has RS profile cams for < $1000 per set. The euro spec is with hydraulic lifters. What are the advantages of hydraulic lifters over mechanical in these motors?

Web Cam Inc. - Performance and Racing Camshafts

JMHO,

12.5:1 is FAR too high for any street car, even with knock sensors. That requires 110 octane fuel, especially in hot weather. Remember now, you are balancing compression ratio, ignition advance and minimal octane. Add summer weather, and those detonation margins evaporate.

52mm RS valves can be installed without new seats.

RS cams are excellent, especially with the RS intake valves. Custom software is needed for this, as you might know. :) Stick with hydraulics and leave the mechanical rockers for the race engines that see 7K+.

Thanks Steve!

This is gonna be FUN!

Hydraulic lifters will eliminate the need for valve adjustments. With mechanical, you need to do that.

That's good to know cuz pulling the the engine to do a valve clearence check would be a pain...

Hey Rick,

I am the OP, and I have not gotten the motor done yet, but it is under way.:D

I sent my heads to Steve, and he reworked them, and added RS intake valves. I bought a set of RS cams from him. He now has my pistons, and will be enlarging the intake pockets on them to allow for the larger RS intake valves. I will be getting Steve to make a chip for me when the build is complete.
Good luck with yours.

Emerald

Nice progress and please post up pics of the heads when Steve is done unshrowding the intake valves
you'll have a torque monster when you're done:)

Here you go Captain, a peak at the heads after Steve worked his magic . I'll post a few pics of the pistons when they return.http://forums.pelicanparts.com/uploa...1278894548.jpg

Lookin good and pls keep the pics comin:)

Well, the last half of the year did not go as planned, but I am finally able to get back to my engine build. I had gotten my heads back from Steve in the last post, and sent him the pistons to have the intake pockets enlarged. They came back looking great, and I managed to get them bolted up. I will try and find my photo of the pistons, as it has gone missing.
I got the cam housings and cam installed, and reassembled the timing chain assembly. I hit a snag when it was time to check the parallelity of the chain sprokets. I was able to get the left on within tollerance with 4 shims, but the right is off by +1mm, and there are no shims to remove. I am currently stumped and scratching my head. I have checked all measurements 5 times, and still end up at the same conclusion. When I took the engine apart, it had 1 shim on the left, and 3 on the right. I changed to a set of RS cams, so maybe this has thrown something out. I can not go forward till I figure it out.http://forums.pelicanparts.com/suppo...s/a_frusty.gif



http://forums.pelicanparts.com/uploa...1293159035.jpg
http://forums.pelicanparts.com/uploa...1293159064.jpg
http://forums.pelicanparts.com/uploa...1293159122.jpg

Happy Holidays to all.

Emerald

Doh..... Well it turned out to be a stupid mistake, as opposed to all of those smart mistakes. I had the right camshaft sprocket on backwards. I need to order a few shims from the dealer, but the measurements now work out, and everything lines up.
I am now looking forward to finishing up when the new shims get here, and then I can start setting the cam timing....

Emerald

Emerald:

Hang in there....and continue on your present course.
You'll be happy in the end.

Rothsport (and Steve Weiner) built me a 3.6 RS Vram motor last winter, and it's a beast.
310 hp w/ 271 ft-lbs of torque.
I have RS cams and intakes, racing springs w/ Ti retainers, Vram induction w/ reflashed ECU.
993 heat exchangers and sport exhaust.

The end result will be worth it.
Great around town drivability coupled with incredibly strong acceleration when you call on it.
Enjoy! :D

Doug,

Thanks for the encouragement. It is a fun project, and it feels good to be getting back into it. I am looking forward to the final result. It sounds like you have the engine I am building. My next hurdle will be setting the timing. I can't say enough about Steve Weiner and his knowledge and dedication to our community. I sent my heads to him because of his great reputation, and then was amazed at his friendliness. He is a true gentleman.

What do you have your engine in?

Emerald

Hi Emerald,

How did you figure out you had a sprocket on backwards? Is the parallel measurement the only way? I have asked this questions before but has not been answered: are there any markings on the sprockets to identify which way they go?

Thanks, and keep up the good work. :)

Good question. I actually stumbled upon it, but the answer was there all along. The easiest answer would be to read Wayne's book on rebuilding Porsche engines. (page 158 figure 6.7) He gives a photo of the sprockets. It is the same sprocket for either side, it is just that one is flipped. I was using the 993 shop manual, and it states to make sure the right side sprocket is facing forward, and forward would be toward the front of the car, not towards the builder. I made the mistake after a long day, and it simply perplexed me, because yes, if the sprockets are backwards, the chains will be out of line and will be off the guide rails.

Thanks a lot!! I have Wayne's book and will study it.

Well, the new year is off to a good start, as I just finished timing the cams. Thanks to Steve Weiner for input and guidance, Wayne's book, and Anthony (Axl911 on Rennlist)

I used Anthony's write up because he condensed it into easy to follow steps. I installed a mechanical lifter on #1 and gapped it to .1mm. I then installed a Z block from Pellican, and installed a digital dial gauge and pre loaded it, then zeroed it. I did not have enough shaft to preload a full 10mm, but figured it was the initial few mm's that were important. When the digital dial is zeroed, it will show the deflection of the intake valve as a negative, which makes sense. I then proceeded to follow these steps...

To set timing for Cylinder 1.
1. Rotate the pulley so Z1 mark is lined up with the case parting line.
2. Install cylinder 1 intake rocker.
3. Make sure both cams have the dots pointed straight UP. Draw a line from the dot through the center of the cam will make it easier to see the dot is pointed straight up.
4. Put the pin into the cam sprocket where the holes line up. Do this for both sides. You can put the cam sprocket bolt in or not. Leaving it out makes it easier to see how the dot moves.
5. Adjust the cylinder #1 intake valve clearance to .1mm like you normally do in valve adjustment.
6. Mount your dial gauge on cylinder #1 intake. And set it to zero value.
7. Rotate the crank pulley clockwise almost 360 degrees. As you approach the Z1 again you will notice the dial begin to move.
8. Continue to rotate clockwise until the gauge moved 1.26mm or .05 inch. STOP.
9. Is the Z1 mark lined up with the case parting line? If not, use a small screw to remove the pin on the left side cam. Rotate the crank pulley until the Z1 mark is lined up with the case parting line.
10. Now put the pin back into the cam sprocket where the holes line up.
11. Double check by rotating the crank pulley 720 degrees. By the time the Z1 comes around for the second time, when the Z1 is lined up with the crank pulley, your dial gauge should have moved 1.26mm or .05 inch.
12. You are done with cylinder #1. Don’t move anything.
13. If it takes more than 360 degrees to get the dial gauge to move 1.26mm, then you either don’t have the cam dot pointed straight up at the beginning or you did not adjust your cylinder 1 valve clearance properly.

Now to set timing for Cylinder 4.
1. After completing the last step in setting timing for cylinder 1, the dot on the right cam should be pointed straight DOWN.
2. Install cylinder 4 intake rocker.
3. Adjust the cylinder 4 intake valve clearance to .1mm like you normally do in valve adjustment.
4. Mount your dial gauge on cylinder 4 intake. And set it to zero value.
5. Rotate the crank pulley clockwise almost 360 degrees. As you approach the Z1 again you will notice the dial begin to move.
6. Continue to rotate clockwise until the gauge moved 1.26mm or .05 inch. STOP.
7. Is the Z1 mark lined up with the case parting line? If not, use a small screw to remove the pin on the RIGHT side cam. Rotate the crank pulley until the Z1 mark is lined up with the case parting line.
8. Put the pin back into the cam sprocket where the holes line up.
9. Double check by rotating the crank pulley 720 degrees. By the time the Z1 comes around for the second time, when the Z1 is lined up with the crank pulley, your dial gauge should have moved 1.26mm or .05 inch.
10. You are done!!!
11. If it takes more than 360 degrees to get the dial gauge to move 1.26mm, then you either don’t have the cam dot pointed straight up at the beginning or you did not adjust your cylinder 4 valve properly.

I used a Stomski top dead center tool to verify my Z1. I also found that when I determined which way the pin needed to be moved, I had to turn the crank so the valve closes, otherwise when the pin is removed, the valve spring will cause the cam to rotate.:mad:
I also used two Z blocks and two dial gauges so I could verify both sides.

I can now start at Z1, turn the crank 360, and the gauge on #1 reads 1.25, and the one on #4 is 0. I turn it another 360, and the gauge on #4 reads 1.23, and #1 is 0. I can repeat this continualy and read the value from 1 then 4.

Here are a couple of photos, and am I missing anything? I had heard that the cam timing was one of the trickiest steps, so now that I have done it, I am a bit paranoid that I missed something.:p

http://forums.pelicanparts.com/uploa...1293992813.jpg
http://forums.pelicanparts.com/uploa...1293992839.jpg

Emerald