3.2L Motronic advice sought, possible 3.4L

[Rockafella]

I am looking at a "light rebuild" of my 3.2L w/86k. It runs fine but is leaking at cyls 1-3 & 6. Yes, I know these cars hate to sit.....

This is a street car that needs to be Cali emissions "passable" every two years. I has a SW chip for exhaust and muffler and I will be running headers w/2 in 2 out.

I figured while I was in there, I would consider the following:

1. Fix top end and put back together
2. Fix top end, add cams (964 or 20/21)
3. Go to 3.4L
4. Go to 3.4L, add cams

I did a search, but I am not able to tell what is best in this situation.

I am trying for the biggest bang for the buck which leads me to option 2.

For just a little more, I was thinking JEs and bore/sleeve my current pistons. This may be in lieu or in conjunction with the cams.

I am looking at this from an incremental parts cost perspective and any guidance or experience is welcome. I know a bunch of board members have done this and I hope you can share the hindsight.

Thanks in advance!

[cnavarro]

Cams - do a search for Camgrinder.

If you do any changes, you'll want to get a chip from another Pelican member, Steve W - 911chips.com. You might want to get one anyways - I just did for my bone stock 964.

Cylinders. You have MANY choices listed from least expensive to most for 98s.

Bore and replate original cylinders
QSC cylinders

(The two above are about the same price)

Perfect Bore (sold by JE)

Mahle Motorsports
LN Engineering Nickies
JB Racing

(The above three are about the same price, although the Mahle stuff fluctuates as much as the exchange rate for the dollar does)

That should give you a starting point for where to direct you choices. Browsing through the Pelican catalog online should also help, since many of the above are in the catalog.

[asphaltgambler]

This is a very, very slipery slope. But here's my opinion.

If you plan on removing the engine assy to re-do the top end go ahead and split the cases and finish it off by at least upgrading the rod bolts.

To me the top end is 75% of the engine assy. Split the case and do it right because if you want more power that means you'll want to turn it up at higher rpm's. The stock rod bolts are the weak spot.

Most likely the layshaft bearings will have seen better days as well. By building a strong foundation first you can ensure the rest of the build will last many miles which ever way you go.

[JeremyD]

In the "been there done that club" I'll second what asphaltgambler said.

probably the 20/21 cam will be the biggest cam you can go and still be emission compatible.

Search for ralph's 3.5 upgrade - that should lead you in the right direction.

[cnavarro]

Yeah, sorry forgot to mention those options too - you can open up the case for machine-in cylinders and go with 100s or 102s, but you really should twin plug at the same time if you do take the engine that far. Not sure how far you want to go.

[Rockafella]

I guess I can go anywhere from here...that's what made all the searching inconclusive at best.

My goal is to build reliability within and admittedly aggressive budget. I am thinking 3.6 conversion if I want more power so I don't intend on building a wild motor. If potential costs get too out of hand, I will just jump to that.

There have been some great points made. I was hoping to avoid splitting the case. Am I being extremely shortsighted by not doing the rod bolts if this car is daily driven and autocrossed at most?

My planned setup right now is top end, 20/21 or equivalent, SW chip, triad 1 3/4 in headers and dual in/out sport muffler. I know the headers are big, but they are what I have in the garage.

This all started as a 7:31 r&p/LSD project......and I thought I was good when I passed the Carrera valve guide test.

[JeremyD]

OK - you asked so here it is...

What I would do if I was you - Since you are in Kali emission territority - I'd recommend that do the following:

964 regrind on your cams. (camgrinder can do this for minimal $$)
top end - valve guides.
Get your rockers reconditioned (camgrinder can do these too)

If you have a good history on the engine (ie consistent oil changes) then leave the bottom end alone.

I'll bet you $500 that your layshaft bearings are showing wear - but you will probably be OK for another 80,000 miles.

leave the headers off -

buy a steve wong chip = put on a euro premuffler and sport muffler (with quality stainless hardware), tuck your catalytic converter away for inspections.

Now, go drive your car.

============================

Probably not as sexy as twin plugging and bore increase - but a hell of alot less expensive.

[Walt Fricke]

R'fella

My 2 cents: If you are going to pull the heads off (and I guess the leakdown showed it was the valves doing the leaking?), why not pull the Ps and Cs as well (not that much extra work at that point) and replace the rod bolts with ARP or Raceware or the equivalent? If splitting the case worries you, you don't have to do that to change rod bolts. You can't use the stretch gauge method of tightening the nuts that way, but for your purposes the torque methods should be fine. It calls for some dexterity, and is not as easy as working on the crank with it on the workbench by itself, but it can be done. I think you'd want an engine stand for this, but you really want one for head removal anyway.

Sure, getting the wrist pin clips out and back in can be a hassle if you haven't done it much, and if you get hasty you can damage a ring on reassembly. But pulling the heads off individually seems like it is more then 50% of the work of a total teardown, so this isn't that much more work.

You say this is a daily driver, but it will be autocrossed. And you want more power than Porsche built into the engine (already more than anyone needs for commuting and sightseeing). I'd say now is the time to fix the 3.2s known weakness, as I suspect you will find occasions to get a return on your power investment more often than not.

Walt Fricke

[Rockafella]

Good point on the rod bolts, since we are potentially swapping pistons/cylinders anyway.

Actually, your comments reminded me of something. This engine has excellent compression and leakdown (175-180 and 3-5% across the board).

It is merely leaking/seeping oil at the cylinder bases. Anything I do is purely preventative. It does not leak at the cam towers, pulley, or rear main seal.

Basically, my mechanic says it is leaking "oddly" since it does not have any of the typical ones.

However, it does have higher than normal play on one of the valve guides. But it is not burning oil excessively and does not smoke at startup or decel.

Part of me wants to retorque the heads and put it back in the car as-is and deal with it when I have a problem......

Am I chasing a perceived rather than a real problem?

[Walt Fricke]

"Part of me wants to retorque the heads and put it back in the car as-is and deal with it when I have a problem......"

That's what I'd do, and save the time and effort for the next project. But I am lazy, and your engine numbers sound pretty good to me.

I've never had a cylinder base leak, at least not enough to motivate me to do something drastic to fix it. Maybe I have had small ones, masked by larger leaks elsewhere (rocker shafts, for instance). Not to the level of drips. But there must be threads on that subject.

By the pictures, you must have cleaned it up really well.

Walt

[Steve W]

Originally posted by Rockafella


For just a little more . . . .

LOLs, that phrase has cost me lots of money through the years. The 3.4 conversion is nice and provides a nice power boost throughout the rpm range of the car, but do it only if you want the extra power, accept the additional costs, plan on keeping the car for at least a few years, and don't look back on what you spent.

[Rockafella]

Steve, I assume I should send my chip back for reprogramming?

So I tentatively decided to go with 98mm QSC cylinders and JE pistons for the 3.4. Here's another phrase that has cost: It's just money.

I am buying them from a source I have never dealt with before. If the are off (as in slightly mismatched), can they be machined to be right?

I am planning on sending the new P&Cs and heads to the machine shop at the same time.

The car is a keeper...I've tried to sell her in the past and she's always conveniently started running bad for the PPI, etc. When I get her home, all is well. It's almost like the car knows and is protesting!

I am hoping I feel the 3.4L power increase at least 5k worth .

[JeremyD]

This sounds like something you "want" to do more than need to do. So I say go for it. If you are going that far - then yes to new ARP rod bolts, yes to to main and layshaft bearings - I'd probably talk to camgrinder about the best cam you can go with and still be emission compliant and I'd look at Extrude Hone to even up our intake runners and I'd also ream out your TB a few extra MM.

While are at it, figure in replacing the carrera fuel line, CHT, and reference sensors.

here's my dyno chart.


Ralph's 3.5 in Red, my 3.4 (with 993ss cams) in Blue, stock 3.2 in green.

[Steve W]

Normally yes, what's ideal for a 3.2 is not for a 3.4, if with all else being equal, 3.4s require 6% more fuel, and if more mods are done, such as cams, headers, Extrude hone, such as in Jeremy's case, then the upper rpm ranges require even more fuel, or the engine will run too lean.

[Rockafella]

Is this considered leaking? And is it enough that you would tear down a motor?



Steve, for reprogramming, would I contact you direct and let you know the final specs?

All, thanks for your insight so far!

[JeremyD]

does it drip and leave a puddle?

[Rockafella]

No drip, no puddle. Garage floor is clean and oil consumption is normal. Oil pressure looks good.

[JeremyD]

I wouldn't touch it. Not yet.

I would start collecting your pennies for a future rebuild, maybe even start collecting parts to offset the sting... I would look at your spark plugs at least every six months.

Monitor your oil consumption.

Go drive it.

[Rockafella]

Re-torquing the heads, buttoning it back up, then going for a drive.....

[Jeff Alton]

I am with Jeremy on this as well, drive it!! When it gives you problems in the future you can decide what to do then.

Cheers