3.6 Engine Breakdown/Rebuild.

tocobill · 10-20-2013, 05:44 AM

So I got around to tearing down my 95 3.6 engine. Turns out the PO had spun a bearing ... that was the unusual sound he heard when he shut it down during a DE.

Got the rods off the crank. Here is the damage. I have seen worse. Journal is rough but uniform. There was still part of the bearing left on the rod ... not much. If it can be polished the crank will also be cross drilled. Not really looking forward to a new crank.

Doesn't look like the FOD did much damage to the rest of the engine. The other journals and bearings look good. Used but good. There wasnt much material in the sump that I found. I plan on cleaning all the oil passages out and replacing the plugs. Looks like some of the skirts got affected. Some scratches are noticeable but I can feel them others I can feel with my finger nail. Cams and housing journals look good .. no damage. Going to be going to the machinist this week to get their opinion.

tocobill · 10-20-2013, 05:47 AM

Here are pics of the heads and P&Cs. I can still see the cross hatched pattern on all the cylinders. There isnt much carbon build up on the pistons and heads either. Again my 2.4 years ago looked worse. Here are some pics ... they are a very good representation of the group.

Thoughts ?

earossi · 10-20-2013, 06:25 AM

Some one with more experience will have to chime in on the crank journal. The pictures don't show it to be not that bad. A machinist should be able to comment. Worst case, you might have to have the rod journals turned undersized. You're going to need to recondition the rods anyway, so I think that the spun rod should clean up nicely along with the rest of the rods.

Not sure how many miles are on your motor, but if it is around 100k you will probably find that the IMS bearings are getting a little tired, which probably justifies the need to split the case anyway. At least when you get done, you'll have a fully rebuilt motor.

earossi · 10-20-2013, 07:19 AM

Have your cylinders checked for taper and out-of-roundness by your machinest. If they are OK, then do not have them touched by any honing process! Simply use Scotchbrite and Dawn liquid washing detergent to remove the glaze that accumulates. Doing a good job with this will insure that the new rings seat in rapidly.

If there are any vertical scores in the cylinders that can be felt with a finger nail, you may have to have the cylinder reconditioned. There are several outfits that do this and match them up with your piston that matches the cylinder.

tocobill · 10-20-2013, 08:55 AM

Thanks. A full rebuild was the plan from the get go. Especially after a bearing failure. There is minor glazing on the upper area of the cylinders. They should clean up. No marring on then. Just the pistons. It looks alot worse in the pictures then it feels by hand. I was turned on to Burtonsville Performance Machine just outside Baltimore by some others. I've been told they are an excellent machine shop and are very familiar with porche engine. I guess they build Indy engine and specialize in cup engines too. Well see what they say about my crank.

964Play · 964Play's Garage

What is the verdict on the crank and pistons? Going through the same situation now, not sure whether to buy a new crank or have it reconditioned.

tocobill · 11-05-2013, 02:43 PM

Crank is away to Marine Crank to work there magic. Hoping they can fix it ... dont want to have to buy a crank. The cylinders are going to be sent off to Charles @ LN to have replated and a set of 10.1 JE FSR pistons w/ valve reliefs cut fitted. The OEM pistons wouldnt work well with carbs and the high lift cams I want to run. I just got done ordering trans parts for my 915 rebuild so Im staggering the new parts orders out ... ITs gonna be a raman noodle mouth ....

.

KTL · 11-06-2013, 12:37 PM

When you have bearing damage like that, you've got to clean everything out. Everything.

Good to hear your cam housings look good. Mine were wasted in the cam bearing bores (so were the cam bearings) but my bearing shower was also much much worse. Be sure to look closely at the housings since the 993 housings have extra passages in them which are quite small. They feed the hydraulic valve adjusters.

See post #16 for a snapshot taken from the 993 manual

How to remove cam tower spray bar

Have to flush the entire external oil system. Oil lines, t-stat & oil filter housing, front cooler, oil tank. Nice thing about the 993 system is the filter built into the t-stat housing. So anything that was scavenged by the pump should be intercepted by that filter before the oil is sent forward to the oil cooler and then back into the oil tank. I would cut open that filter to get a feel for just how much bearing material it collected. That bearing is pretty thin now! I would also cut open the smaller filter on the engine to see what may have found its way past the other filter.

So theoretically the cooler and tank should require not much cleaning because the scavenge filter should have protected them. But i'd still STRONGLY recommend you either disassemble that t-stat & filter housing or replace with known good used one. You need to get in there and clean out any bearing debris that is hiding in the temperature regulator or the nooks of the housing casting.

I can extract the pages from the manual for the cam housing, rocker arms and t-stat + filter housing if you'd like

You should also consider disassembling your oil pump. It'll confirm for you what I suspect is a damaged housing. The pump may spin freely and the gerotors/gears look OK. But when you open the pump, here's what you're probably going to see but not as bad as mine shown below. There has to be some damage inside the pump because whatever debris you find in the scavenge filter, it got there by going thru the scavenge portion of the pump

Gotta go thru the whole oil system, anywhere oil goes, to prevent some stray chunk of debris from messing things up all over again. Probably would be wise to remove the piston squirters to make sure there's no debris hiding in those passages. Theoretically the large scavenge filter and the smaller pressure filter should have caught debris before it got to the squirters. But you never can tell and you have to be extra cautious considering that the source of the debris is where you want the cleanest oil to be!

There's some pretty good oil diagrams in my thread where I shared my woes

Engine Bearing Failure- Disassemble Heads Too?

tocobill · 11-06-2013, 03:42 PM

Thanks Kevin. After looking at your thread a while back I took lots of notes. My pump is good ... didnt get the FOD that you had in your system. Best parts about this rebuild is that the engine spun the bearing in someone elses car and oil system. I got the engine after all this so I dont have to worry about the FOD in my system other then the engine. I will be opening up the gallery plugs soon to clean them out. The cam towers look good too. I really lucked out with this engine .. It could have been alot worse. Im going to send the towers to Bob @ Anchor Atlantic to clean everything up there. He has the big ultra sonic tanks and is familiar with the set up. I didnt know he did these but he does them along with the heads. Just waiting on hearing from Marine Crank to find out the news. Im holding off on sending my cylinders off to Charles for this reason just incase they cant fix it and I change direction with the build. Same deal with ordering the pauter rods and pistons too. Everything is dependent on the crank.

KTL · 11-07-2013, 06:32 AM

Good to hear your pump is OK. I'm surprised with a bearing spun as bad as yours that the pump didn't pick up any of the junk the rod spit out.

Fantastic news that you don't have to deal with the external oil system cleaning. That is some tedious, sometimes expensive, work. Good to hear Anchor does the cam housings. I suspect they take a bit of work to clean and might be a good idea to have them pop the balls out and replace with plugs. John @ Costa Mesa R&D has said these are commonly found loose and leak

https://www.youtube.com/watch?v=aWLsKUJCy0A

Marine will be able to salvage your crank. The damage was pretty standard. They can either grind it or weld & grind to keep it STD.

tocobill · 11-07-2013, 06:42 AM

Nice video! Ive seen a few of his youtube posts. The last PO used a roll lock biscut to clean up the surface. Bob is going to take a skim cut just to clean it up. Should be much. I doubt that anything will have to be shimmed afterwards. I didnt look at the towers that to much to see the surface. Was more concerned with the cam gallery journals. Im sure the tower will look the same. I do like the set screw idea for the ball plugs.

I didnt realized the 993 went back to Mg based casing for the pumps. Curious why they did this weight savings or cost? The internals of the case are still smooth. The rotors of the pump looked good too.

KTL · 11-07-2013, 08:18 AM

Yeah not a bad idea to surface it, especially since somebody previously scuffed it up. I put mine on a glass plate with some sheets of wetsand paper taped down. Works ok for light cleaning of the surface. Works nice to clean up the valve cover surfaces too

Some 993 are Mg and some are aluminum. The later ones are aluminum and I think all of the 993TT were aluminum? Not 100% sure on that. What's the date stamp on your pump?

I do know that the current pump would be a 996TT pump if you were to buy a replacement. That's definitely aluminum. The 964 were all Mg except for the Turbo was spec'd to use the real deal 930 pump. Then when the 993 came along, all engines (including the new turbo) used a 964 style pump that eventually was aluminum

Some guys have observed the 964 Mg pumps with cracking in the casting. Maybe that's what prompted it to evolve to aluminum again? My first 964 pump was real nice. Shame on me for toasting it. Replacement I got was an older 964 pump and it cleaned up fine but some areas of the casting showed "erosion." You could wipe the pump off in some places where the surface of the Mg had turned to a thin layer of Mg goop/sludge.

I don't know what prompted the pump to be Mg after they had such good history with the aluminum in the SC, Carrera & 930 pumps. Mg isn't cheap, is it? I guess it's got a pretty good strength-weight ratio. Just doesn't seem to be as durable long term as aluminum.

tocobill · 11-07-2013, 08:28 AM

Its def an early 993 engine so it has alot of the late 964 stuff on it. I thought about going to a GT3 pump but there are stupid money right now. Im going to get all the other bottom end stuff taken care of now ... maybe later down the road Ill do the pump. So I was reading the other day about 993 cases having cracks in them from vibration stress due to shuffle pinning the cases to make them more rigid and maybe to rigid ... Thoughts?

KTL · 11-07-2013, 09:06 AM

Yeah the GT3 pump is big bux these days. I tend to think the old 930 or new 996TT is a good compromise. The older engines get by with the "tiny" SC pumps so I tend to think the more modern stock pumps are pretty good. Just a gut feeling/guess on my part. Plus the 3.6 engines are feeding more oil to the bottom end anyway with their restricted flow to the cam housings?

Not familiar with the 993 case cracking. Where do the 993 cases crack? Seems to me that would be a crankshaft issue if its vibration related? Long stroke crank & some big 'ol pistons flying around with so-so conrods.

Kind of a damned if you do, damned if you don't sorta thing. Don't pin the case and it shuffles like any other original engine case. Pin it and it breaks the case? Well then i'd select the lesser of two evils and not pin it. Plenty of engine cases last a long time w/out pinning. I suspect only the considerably high revving cases truly warrant it?

Funny you mention the pinning. Paid a visit to see the guys at G2 last month to have cgarr sleeve my case since it's 3.0L SC case that's been used for racing for quite a long time. Main bearing parting line surfaces are a bit fretted from years of wiggling. So Craig put it on the table to see how much would have to come off the mating surfaces to clean them up. Not much at all, so it didn't have to be bored back to standard. Then he's got a trick to sleeve bearings 2 thru 7 similar to how #1 is sleeved. Makes a real sturdy case. We'll see if mine cracks?

tocobill · 11-26-2013, 06:33 AM

Picked my heads up today from Bob @ Anchor Atlantic. I have to say Im very impressed with the rebuild job and time frame it was completed. Plus hes a super nice guy! He meet me at a location that was convenient for me to drop off and pick up ... pretty much knocked a couple hours off the trip. I had him regrind the seats for 993 RS spec valves and installed the Aasco springs and Ti retainers. He cleaned up the old Na filled OEM valves and measured them for me ... didnt really have to do that either .. just good quality workmanship. Dropped off the cam towers to have cleaned ultrasonically after I got all the gallery plugs removed. Dropped off a bunch of old transmission cases for cleaning to make the trip to southern NJ worth it. The bad of candy hidden in the parts was a nice touch, .

Talked to David @ Marine Crank while driving up to NJ. Said the crank was about finished. Didnt mention anything out of the ordinary so I assume they had no problems bringing the journal back to Std/std and preforming the crank grooving/x-drilling mods. He did say he had to go out and find my crank in the workshop ... still waiting for a call back. Once I get nod the crank is good to go I can send off the cylinders to LN/Millennium for replating/fitting the new JE pistons and order my new Pauter rods.

Case cleaning is up next.

r-mm · 11-28-2013, 07:24 AM

Bob does great work. When my heads came back i wished i had dropped the majority of the rest of the motor off with him. Im sure his rates would have been reasonable for add'l cleaning since it seems to be his bread and butter.

tocobill · 11-29-2013, 08:57 PM

^^^^^^Yes he does. Got an email from him today. Everything is cleaned and ready to be picked up. That was super quick. Ill post some pics when I get everything in a couple days.

tocobill · 12-02-2013, 04:14 PM

Got my towers back today along with the trans cases. I media blasted the nose cone and center section before dropping them off. The bell housing had been soaked and mildly degreased. There is still a bit of hard surface corrosion I assumed would have been removed by the ultrasonic cleaning. Im going the bead blast them again to remove this then cleaned again. Other then that they are clean as a whistle. The cam towers are spotless. All the carbon was removed from the SAI ports. I removed all the plugs but the 2 larger ones. I got them started but gave up. I thought the little bastards would have been harder. Didnt help I was doing it in my kitchen instead of my shop, lol. Bob spent the extra time to pull the plugs fro me since I was very adamant of doing this since the bearing failure. The cam tower bearing surfaces look better. They are not polished but nor are they scored .. just dull. Must be from dirty oil I suppose. I think I can clean them up if needed. Here is a shot of them. They all look like this or better.

Hard surface corrosion. The middle case had it one it as well. Glass bead took it right off. Middle case is spotless now. Just have to blast the bell housing ... it wasn't touched the first time.

KTL · 12-03-2013, 12:43 PM

Cam bearing bores don't look too bad. Pretty common for that scuffing to be on there, as i've seen it on a lot of older housings. Not proud to say i've fiddled with more than my fair share of cam housings. Why that is I don't know......

tocobill · 12-03-2013, 01:11 PM

I feel your pain Kevin. I bought a 930 turbo pump so Ive taken my 993 pump apart to clean, photo, and sell. I think if will be a very good upgrade. Seems like next go around piece meal buying of engine parts really does seem the best route then trying to buy a core. Its a very dark art to buy good usable engine with no history. Ive happened to luck out but I could see how someone could spend tons of money and end up having to replace everything.