Engine assembly tips...

[Tom '74 911]

I've been just about ready to start assembling a 2.7L long block for what seems like months and was thinking about this thread which discusses beveling the backside of the oil supply holes on the main bearings. For a novice like myself, this seems like a generously shared, great tip that's not covered in any of the typically available and utilized resources.

Main bearing install tip.

I'd love to learn about other little tips like this that some of the more experienced builders have picked up over the years. I understand that a lot of this knowledge is hard-won and proprietary and guarded, but any little extra bit that advances reliability or performance I'm sure would benefit more than a few future rebuilds.

I'm sure there are a few folks that post here that could write a book... that I would buy!

Thanks,
Tom

[Catorce]

Tom,

I've found that all the "important" tips are found in Wayne's book, which I hope you have, but he understates many of them.

For example, the biggest tip I could give for building a motor is to ABSOLUTELY use the metal strips that hold the rods up in the air as well as the chain. There is a Porsche tool number associated with these - you can buy them from Baum tools or make them as per Wayne's book.

He doesn't really mention in the book that the use of the rod / chain holders is CRITICAL to preventing leaks on the case, but it is.

I have assembled many motors; early on, I'd have a second person hold up the rods and pass the chain through the opening. Invariably, minute quantities of Loctite 574 were smudged on the case parting lines which resulted in minor but annoying leaks.

Using the chain / rod holders means mating the case surfaces is a one man job but more importantly it removes your fingers from being anywhere near the case parting surfaces and makes it so that the mating and the adhesive is perfect and leak free.

Sure, the car will run fine with leaks, but who wants leaks on a brand new build?

[Trackrash]

Agreed. Wayne's book has all the info needed to assemble a stock motor. If you are not clear about something, ask it here.

Now if you are building a hot rod or using aftermarket or modified parts, there may be issues to contend with not in Wayne's book.

[Tom '74 911]

Originally Posted by Catorce

I've found that all the "important" tips are found in Wayne's book, which I hope you have, but he understates many of them.

Originally Posted by Trackrash

Agreed. Wayne's book has all the info needed to assemble a stock motor.

Thanks Adam & Trackrash, I appreciate your responses. I do have a copy of Wayne's book and am using it as my primary resource. It's nice to know that it covers the important stuff. I also have the factory manuals & a few others... along with this great forum.

My build is mostly tried & true 2.7L w/RS P&C's, 964 cam, likely carbs, possibly EFI. Motor will be a nice, durable, drivable street motor, not a high strung race motor - 100% street.

Just last week I fabricated a set of the sheet metal strip tools for mating the case halves, using the image w/dimensions in Wayne's book as a guide.

Thanks again!
Tom

[fanaudical]

I recommend reading through the "Complete Engine Sealant Thread":

The Complete Engine Sealant Thread...

There is some "spirited discussion" in there, but it's a worthwhile read. Lots of tips in there regarding how to avoid leaks on a rebuild.

Looking back on my rebuild, my best tips are:

- Case prep is important. Verify all your squirters work, all the galleys are clear, no chips, etc. Make sure the case is spotless and everything works before you start assembly.

- Plan ahead relentlessly; make checklists for everything and stick to it. Break it down into small assembly steps. Validate the checklist and then do the assembly. Don't get in a rush. Don't take shortcuts. Stop when you have questions and research. It's better to let things sit for a few days while you figure it out than to wake up in the middle of the night wondering if you did something right/wrong.

- Keep everything clean, organized, packaged until ready to clean and install, and then do more cleaning.

- Definitely upgrade the oil pump and do the case by-pass mod. This is one of the keys to a happy, cool motor.

[Catorce]

Strips look great! Good job!

[Tippy]

Originally Posted by Catorce

Strips look great! Good job!

Coming from the guy who is making engine cases from scratch, that is a compliment!

[KTL]

I'm no pro and just above a hack. So take my advice with a grain of road salt.

• Lightly beveling the case through bolt holes with a countersink to minimize the amount of o-ring murder that occurs when you tighten the through bolts. It seems that the o-rings in the gasket kits are larger than the originals and that creates more crush than desired.
  
• The recommendation in Wayne's book to use RTV silicone as a "belt-and-suspenders" extra measure of protection in the through bolt sealing area is not my cup of tea since I have a massive fear of that stuff and hate cleaning it up after it's cured. So I won't get into that debate. Ooops, I just did but let's not go there.........
  
• You'll likely notice that the interface of the main bearing saddles looks like it was machined differently than the case parting line, if untouched (not likely since you're assembling a 2.7 mag case). That's a sign of shuffling going on there. Use a very very very thin coat of 574 here, since it has some shear resistant ability unlike most other sealants.
  
• Break the sharp edges of any oil passages with a fine file. Like the oil inlet port behind the oil cooler and the passages where the oil pump mates with the case halves
  
• DON'T use Curil T on the periphery of the radial seals for the crank. That just invites the seal to walk its way out or leak. All you need is a bit of spit or water or whatever to provide some slip in the rubber-aluminum interface as the seal moves its way into the bore. You want whatever "lubricant" you use to dry and no longer lubricate after you're done installing the seal. Curil T never cures. Funny how its name has cure in it........
  
• Lube the lips/ID of the seals with a swab of oil to avoid a dry startup. Also put some dabs of grease on the garter spring to hold it on there, in case you choose to drive the seal in place with a suitable guide piece and hammer, so the spring doesn't hop off the seal.
  
• Thinner is better when it comes to sealant application. Especially when it comes to the cam housings- just a paper thin layer around the openings for the valves and the bolting holes in the cam valley. DO NOT coat the entire machined underbelly in orange (if using Loctite 574) like Wayne's book shows. That's completely unnecessary and makes for a TON of extra squeeze-out, and future cleanup, the next time it's disassembled.
  
• Check the flatness of the cam bore at the gasket surface where the thrust plate mounts to it. This area is sensitive to leaking & the amount of contact surface for the gasket is quite small given the width of the gasket here. In fact this area is often not all that flat on the cam housing itself. You can verify this by coloring it with a permanent marker and then rub the housing on a known very flat surface with some 400 grit wet sandpaper. You'll be quite surprised how much marker does NOT rub off after a handful of passes across the paper. Also a good idea to check the thrust plate for flatness. That's an easy one to true up.
  
• After you set that thrust plate in place (use some silicone paste or oil on the thick o-ring to help slide the thrust plate home), check behind the chain box to see that the gasket has not gone off alignment.
  
• Make sure the epoxy on the back side of the chain boxes is not applied too thick. Too thick and it'll contact the cam housing and the above gasket can leak badly.
  
• Use a false/mechanical tensioner set to set your cam timing. They allow you to turn out the adjuster bolt and therefore set your chain tension by "feel" vs. just clamping the chain with a vise grip/welding clamp or whatever. It'll make you feel better about getting your timing the same on both sides. Also nice to have two Z-blocks and dial indicators so you can see your timing on both sides- reduces setup error by transferring the block + dial setup to the other side. I really don't care for the alignment that the Z-block establishes for the dial indicator plunger. Stomski's setup is better for placing the plunger at a perpendicular to the valve spring retainer.
  
• Make sure your four inner chain ramps engage the mounting bolts properly inside the case. It's easy to think the ramp just pops onto the nipple of the bolt quite easily but it doesn't. The ramp just gets pushed against the back of the case and doesn't fully seat onto the bolt. Yes, the ramp isn't going to fall off the bolt. But the ramp isn't well aligned with the chain.

[JFairman]

Pieces of pipe strap work well for holding the chain and 3 of the rods up too.
You can get the other strips of sheet metal at Home Depot. Around here they're used with nails during new house builds to strap down roof trusses to help keep them on during hurricanes.

[Gordo2]

Originally Posted by Tom '74 911

Midway down this thread Gordo's 3.2L Engine Rebuild - Ready to Reassemble check my post on my homemade chain & piston rod keepers.

Make sure the material you used isn't too wide to fit through the case half, or you could find some undue excitement.

Gordo

[Dpmulvan]

1.Do not drink alcohol, smoke weed or take lsd during rebuild.

[Tippy]

KTL, those are great tips!!!!

Those should be added to Wayne's book for sure. That is experience talking, as I remember every single thing you said when I rebuilt mine 5 years ago or so.

[Tom '74 911]

Yes, thank you for the continued great tip sharing.

Originally Posted by Dpmulvan

1.Do not drink alcohol, smoke weed or take lsd during rebuild.

This one's pretty easy for me... : ) : ) I'm pretty boring when it comes to all that stuff, which is not a bad thing!

[brighton911]

I agree with the others that Wayne's book is a wealth of assembly info. The only thing you might want to seek further opinions on is the suggested use of Loctite on rod bolts/nuts. I recommend against it but I do recommend the use of ARP of similar bolts torqued using a stretch gauge. And that would mean you should get the big end of the rod re-sized to ensure they are round and the correct size.

[Tom '74 911]

Originally Posted by Gordo2

Midway down this thread Gordo's 3.2L Engine Rebuild - Ready to Reassemble check my post on my homemade chain & piston rod keepers.

Make sure the material you used isn't too wide to fit through the case half, or you could find some undue excitement.

Gordo

Gordo,

Thank you for this. I did a practice assembly yesterday, which I originally WASN'T going to do and guess what... glad as he11 I did as my chain holder strip didn't fit through the left case half opening. That would have stressed me out big time if the sealant applied stopwatch had started already... fixed now though!

Thanks,
Tom

[Steam Driver]

1. No silicone seal anywhere. Silicone GREASE on “O” rings, but not SEAL. Si sealant defeats the design purpose of an “O” ring and will make it leak.

2. Have trouble holding onto those slippery rocker shafts when removing or replacing, particularly replacing? Try an electricians fuse puller. Generally plastic so they won’t harm the rocker shaft, curved notches to fit.

3. (The following only works with the engine out of the car and already being disassembled.). Trouble removing rocker shafts? Get some 1/4 inch all-thread that will reach from the rear of the cam housing to #1/#4. With the rocker shaft bolts removed you can run this through the shafts to the difficult one. A small washer will just fit in the shaft bore. Put a small washer and nut on this, then use the rod to pull the shaft. If particularly difficult put a length of small PVC pipe over the all-thread and up against the cam housing, then another washer and nut and use it as a puller.

4. You can also use PVC pipe as a “pusher” to help get tight rocker shafts installed. Again this is only when the engine is dropped.

[gtc]

I would suggest using a non-liquid assembly lube. I believe Redline and Joe Gibbs both make an assembly grease.
I used Brad Penn assembly lube on my rod and main bearings, and it would drip out of the cylinder spigots when I rotated the engine case during assembly.

[Emo993]

Finally putting new PMO 40's on my 2.2 E with S pistons. With the new manifolds came longer intake studs. What Loctite should I used, intake studs to heads. Thanks, Mark

[Drbraunsr]

Mark the tightening sequence of the case thru-bolts on the case with a Sharpie ( it wipes off easy with a little laquer thinner).

Buy (and use) Stomski's circlip injector tool. It's patented for a reason. I couldn't imagine installing the circlips without it.

[Pazuzu]

Originally Posted by Dpmulvan

1.Do not drink alcohol, smoke weed or take lsd during rebuild.

Booze DOES help when cleaning everything though

Squirt some clean, scrub with brush, swig a beer, repeat. for DAYS.