3.2 top end rebuild progressing to a 3.4 - basic questions.

[Peter M]

Originally Posted by Cloggie

Cloggie,
Will the standard Carrera 3.2 AC compressor fit or do you have to use the possibly shorter compressor fitted to 964/993's to provide sufficient clearance between the end of the compressor and the intake manifold?

[Cloggie]

Originally Posted by Peter M

Cloggie,
Will the standard Carrera 3.2 AC compressor fit or do you have to use the shorter compressor fitted to 964/993's to provide sufficient clearance between the end of the compressor and the intake manifold?

It is an awfully small space and have not bought the AC compressor yet. I had been looking at the Sanden 505 - baby brother of the commonly used 507 - as it is shorter and I really do not need AC all that much, so if has less capacity that's OK.

I am also prepared to redo the fuel lines, probably putting in a banjo there which will gain a little space.

That will get done this winter, right now the priority is getting the engine in the car, running and tuned.

D.

[PeteKz]

I'm not an AC guru, however, I'll condense what I've read here and my moderate experience with AC in other cars:

The compressor does not usually limit AC performance. That appears to be the case with 911's too. Instead, what limits AC performance is the condenser. That's why most 911 AC systems have 2 of them. The evaporator also limits performance, but there is almost no room to change that in the 911, unless you change to the Classic Retrofit electric AC setup.

[Cloggie]

Originally Posted by PeteKz

I'm not an AC guru, however, I'll condense what I've read here and my moderate experience with AC in other cars:

The compressor does not usually limit AC performance. That appears to be the case with 911's too. Instead, what limits AC performance is the condenser. That's why most 911 AC systems have 2 of them. The evaporator also limits performance, but there is almost no room to change that in the 911, unless you change to the Classic Retrofit electric AC setup.

I agree with your assessment and it has formed the basis of what was done for this issue in addition to an upgraded evaporator and fan courtesy of Griffiths.



Its a 993 condenser and 964 lines.....besides getting all the condenser crap out of the engine compartment and helping with the engine cooling a little bit, it also moves a bit of weight forward.


...but back to engines, just finished the last piece of wiring yesterday, busy today but I think tomorrow the engine comes off of the stand and gets mated to the transmission. Sorta scared about that as I am terrified of dropping the thing and all I have are the wives to assist....and both are under 50kg.....

D.

[brighton911]

Re getting it off the stand, best have an overhead sling and winch fully supporting the engine weight. If it gets away from your team, really bad things can/will happen.

[Cloggie]

Originally Posted by brighton911

Re getting it off the stand, best have an overhead sling and winch fully supporting the engine weight. If it gets away from your team, really bad things can/will happen.

I have a 1 ton chain hoist with a strong mount on a big roof beam - about 1 m tall and 30 cm wide, so I ought to be OK....just nervous is all, as falling is a bad thing for sure...

D.

[Henry Schmidt]

Originally Posted by Cloggie

I have a 1 ton chain hoist with a strong mount on a big roof beam - about 1 m tall and 30 cm wide, so I ought to be OK....just nervous is all, as falling is a bad thing for sure...

D.

Way back when, I was moving a 911 engine on a 3 legged stand when one wheel caught on the concrete causing the engine to tip over. Instinctively a stuck my leg under the engine to break the fall. I never did that again. Caution is the key.

[Cloggie]

Originally Posted by Henry Schmidt

Way back when, I was moving a 911 engine on a 3 legged stand when one wheel caught on the concrete causing the engine to tip over. Instinctively a stuck my leg under the engine to break the fall. I never did that again. Caution is the key.

Holy merde! Did you sacrifice your leg to protect the engine and was the engine damaged? I can only imagine what would happen if I dropped the thing.....scary thought.

....and yes, I will be hoisting a few inches, make sure its stable, remove the stand. Then get the jack with the neat little engine carrier our host sells under it asap and get it lowered to ground level as soon as possible.

I have a very high lift AC Hydraulic jack andn that little carrier seems to be pretty well fitting and makes the whole thing stable.

I am pretty sure I will be OK.....

https://www.pelicanparts.com/More_Info/PW011000002.htm?pn=PW-01-100-0002&bc=c&SVSVSI=0602

[85RedCarrera]

Following this thread with great interest.

I am building a single-plug, smogged 3.2 to 3.4 to run on 91 octane right now, and I'm getting close to closing up my case. Using Mahle Max Moritz style crowns (crown volume: 35.8cc) 98mm 10.1:1 pistons. Dougherty has re-ground my cams to 964 specs. I will probably retain the stock HE's with an aftermarket pre-muffler & exhaust. Steve Wong chip also. Supertec head studs and ARP rod bolts.

I just got my heads back from the machine shop- a slight chamfer was machined into the combustion chamber circumference for the 98mm pistons. My old burette broke, so another is on its way- I still need to measure chamber volumes and measure deck heights to compute my static CR.

I have found some erroneous info on the web regarding the 3.2 to 3.4L Mahle piston kits- the 3.0 to 3.2 Mahle piston/cyl kit is offered as a 9.8:1 CR with a 35.4cc crown volume. The 3.2 to 3.4 Mahle piston/cyl kits offered are- 11:1 (43.2 crown volume) or a 10.1:1 (35.8cc crown volume). (Mahle pistons for the L&N Nikies cyl's might be something different...IDK)

It is interesting to note that (per Mahle) the 11:1 piston's CR is based upon running a twin-plug head with a 92cc chamber volume (presumably, the extra plug hole increases chamber vol by ~2cc ?). I am also guessing that this piston is NOT a Max Moritz style piston, as it is also designed for higher lift cams.

My heads were fly-cut, chamfered, and all of the valve seats were re-ground. All valves were serviceable, so re-used & re-ground. Shifting valve heights/re-surfacing the heads and the chamfer will all affect the chamber volume, and I am curious to see what it is all going to add up to vs. the supposed 90cc factory chamber volume. I am guessing that the sinking of the valves will produce the largest change to the chamber volumes.

I am hoping that the CR will come in at something lower than 10:1, so that I don't need to pull out too much ign timing. I don't think I will be needing cylinder base shims (would prefer not to), but we'll see.

I will post my individual chamber volumes here, along with my deck height(s), once I have them.

Mahle 98mm 10.1:1 piston/Cyl kit specs:

[silverlock]

The 964 cam is very mild: good for CIS builds where you can’t have much overlap (sensor plate reverb) but leaves a lot on the table for EFI/Motronic.

A more aggressive cam would also avoid you having to overthink your CR, as your dynamic CR — which is what matters — will be lower. Shimming your cylinders to further lower the CR is just throwing power away.

10.2:1 single plug here + 993SS cams on a 3.2SS = ~7.78:1 dynamic CR.

[85RedCarrera]

Originally Posted by silverlock

The 964 cam is very mild: good for CIS builds where you can’t have much overlap (sensor plate reverb) but leaves a lot on the table for EFI/Motronic.

A more aggressive cam would also avoid you having to overthink your CR, as your dynamic CR — which is what matters — will be lower. Shimming your cylinders to further lower the CR is just throwing power away.

10.2:1 single plug here + 993SS cams on a 3.2SS = ~7.78:1 dynamic CR.

Understood. The reason I am going with a 964 cam is the same reason that I am not going with twin plug heads- At the moment, the engine has to pass visual and tailpipe emissions tests... I would have loved to have gone with something like the DC cam, but I could not find any data regarding owners having success with it during a smog check. I do not want to have to pull the cams out if it doesn't pass emissions, so I chose not to roll the dice and left those hp gains on the table....

The 964 cam was chosen as a compromise between performance and passing emissions. The stock 3.2 cam, is very mild- the 964 does have something to offer in comparison... that said, I am not expecting much from the 964 cams- my 3.2 cams needed to be re-ground, and so rather than go with stock I decided to bump it up just a little.

If I was in another state, many things about this build would definitely change!

[fallingat120mph]

Sorry gents...I guess I wasn't subscribed to my own thread or it never took when created. Glad this morphed into something that has helped some people.

In the end, I went with Mahle 98mm P/C (11:1), 993 cams, twin plug set up as basics.

Steve W. just finished my DME/ECU conversion for the project. I will be running the 993/964 ignition set up w/ CR at 10:5 on 91 octane.


Only have a brief photo as I am on the road for a few weeks...






Keeping the heat with 41mm OD SSI exchangers and an M/K 2in2out exhaust.

This has been my first attempt at what was going to be a top end rebuild to moving up to a 3.4 build. Between Bruce Anderson's books, my mechanic and the forums been quite an adventure. Still a lot to learn and claim zero expertise but I understand so much more and can't believe how this has made ownership so much better and more personal.

I am so impressed with those of you who do this on your own and have the time and knowledge.

I really wanted to have a real go at it (at least a basic top end), but with my wife and I's lifestyle and 2 moves in the past few years had to over the shoulder a lot of this with my mechanic and his shop - which I am very grateful.

Still a ways to go, but I am very happy with where I have ended up.

When I get home I will try and post some photos of the progress as it was happening this spring/summer.

Erik

[fallingat120mph]

...and, thank you to everyone posting here.

I am not going to say "the while you are in there" is not a real thing but when you really start to compare things, I will say, a lot of the upgrades do make sense -and it pains me to say that

It has definitely cost more, but this car is going to the grave with me and yes, a 3.6 probably would have been 'better' or other options for more HP, in the end I felt most confident with this path, with my knowledge base, expense and time.


Erik

[fallingat120mph]

Originally Posted by Cloggie

Henry, your suggestion was spot on. Bought the swiveled socket just like your picture - I did not know such things existed and the nuts went on quite easily.

Air cleaner now fitted, probably will cut down the snorkel a bit, although Grok tells me there is no material difference in air flow between the 57 mm diameter as it is versus the 77mm diameter I want to cut it down to.





D.

Nicely done!

[PeteKz]

Erik, I've often considered that I should have just bought a complete 3.6 engine 5 years ago for $15K or so and sold my 3.0 as a core. Oh well, "next time."

[fallingat120mph]

Originally Posted by PeteKz

Erik, I've often considered that I should have just bought a complete 3.6 engine 5 years ago for $15K or so and sold my 3.0 as a core. Oh well, "next time."

"oh, well, maybe next time..."

I have said that to my mechanic a many times over the past few months

[Cloggie]

Originally Posted by fallingat120mph

Sorry gents...I guess I wasn't subscribed to my own thread or it never took when created. Glad this morphed into something that has helped some people.

In the end, I went with Mahle 98mm P/C (11:1), 993 cams, twin plug set up as basics.

Steve W. just finished my DME/ECU conversion for the project. I will be running the 993/964 ignition set up w/ CR at 10:5 on 91 octane.


Only have a brief photo as I am on the road for a few weeks...






Keeping the heat with 41mm OD SSI exchangers and an M/K 2in2out exhaust.

This has been my first attempt at what was going to be a top end rebuild to moving up to a 3.4 build. Between Bruce Anderson's books, my mechanic and the forums been quite an adventure. Still a lot to learn and claim zero expertise but I understand so much more and can't believe how this has made ownership so much better and more personal.

I am so impressed with those of you who do this on your own and have the time and knowledge.

I really wanted to have a real go at it (at least a basic top end), but with my wife and I's lifestyle and 2 moves in the past few years had to over the shoulder a lot of this with my mechanic and his shop - which I am very grateful.

Still a ways to go, but I am very happy with where I have ended up.

When I get home I will try and post some photos of the progress as it was happening this spring/summer.

Erik

Looking awfully fine...nice job and ain't it fun!!

D.

[Glenfield]

Cloggie, motor is coming together very well. Love the early airbox.

Have you had a chance to test fit it in your engine bay? My 3.4L on PMOs (long manifolds) with an early air filter is an extremely tight fit. Had to shim engine to lower it and it's still marginal and will need to find a way to lower further. Just a heads up since you're very nearly there on your build.

[85RedCarrera]

I just finished measuring my rebuilt cyl head combustion chamber volumes with my burette & plexi cover plate. Here's what they came in at:

cc's

90.5
92.5
91.25
91.8
92.6
92.0

This seems like a rather wide variance to me....

This will give me various static CR's from 9.7:1 to 10:1.

I am curious as to what should be considered as "acceptable" variations? I assumed that the chamber would have their volumes equalized much closer than this.

What do you think?

[brighton911]

Good thing you measured them Dave, that's quite the variation. I would say not a good thing, it's time to even them out.