Jaybird's official 2.7 rebuild thread

[jaybird840]

Well guys, it's time to kick off the official rebuild thread. I'm the proud owner of a nice looking (IMHO) '75 914 1.8. My dream has been to build it into a "supercar" of sorts. Here is a pic of the car.


I chassis dynoed the car with the factory 1.8L four--59 rwhp and 70 ft/lb torque. That will never work!! So, for months the debate raged... Jake Raby Massive Type 4, or stuff in a six. After weeks of agony, and staring at the 2.7 six I'd purchased from a fellow pelicanite, I decided that the teardown of the 2.7 would be the deciding factor. So far, the 2.7is winning. I didn't document much in the early going, but I'm down to things that make a difference now. Here sits the motor on the stand sans the left heads/cam tower.


When I pulled the heads off, here are the pistons I found.... Definitely not CIS, but what?



To be continued......

[jaybird840]

The internals of the heads don't appear to be bad, either. No apparent valve damage, piston damage, or serious cracks.....



Got awfully freakin' lucky, and found what I believe are Nikasil cylinders... Nice crosshatch pattern, and magnetic.



And, if I'm extremely lucky... These will turn out to be time certs or case savers. No pulled or broken head studs....




More tomorrow!!!

[jaybird840]

Well, I thought I might try to get a bit more done today, so I pulled the right side heads/cam towers... then the book says cylinders come off, so.......






Wow, that was slick and easy. No binding, warpage, etc... just gentle taps with a rubber mallet, and "whoooosh" they slid right off. Well then, I say to myself, let's at least get started on the pistons... Could take a few hours. I found a tool that I liked better than a screwdriver for the circlips. Harbor Freight pack o' four....



No need to whack, coax, etc. Just put the pointy end under the circlip, cover it with your thumb, and it pops right out. I didn't even need to tap the wrist pins. They were snug with no slop, but I just mashed them out with my thumb. I had all the pistons off in under 10 minutes. I can't believe I'm this lucky--gotta have a broken crank or something lurking underneath. All the piston bores looked good to me (novice rebuilder) with no scuffing, etc. So, it's now officially a short block.






I took the pulley off the end of the crank with a breaker bar, and then moved to the flywheel. I realized I don't have the correct flywheel tool... I'll be ordering it shortly. In the interim, I hosed the flywheel bolts with PB Blaster. Maybe that will give me a head start on them while I wait for the flywheel bolt tool....

More later!

[jaybird840]

Well, I found myself with a few more hours to work on the motor today. I'm still trying to run down the 12pt-12mm tool for the flywheel bolts. So, I thought I'd tackle the head/rocker arm/camshaft disassembly. The rocker pinch bolts were torqued down pretty hard, and were crusty. They came loose with some gentle persuasion, and came out with no major issues. Here is a pic of the left side camshaft coming out of the housing after the rockers were removed....



I knew I was due for my first "bummer" of the rebuild I have some pitting on a couple of the camshaft lobes, so I guess it's off for a regrind...



After removing the camshaft, and the last six nuts that can't be reached with the rockers on, I was able to remove the heads. It took a bit of tapping on the studs to get the heads to drop free. Here is the left side completely disassembled.



As always... more to follow!

[cgarr]

Check with NAPA, they should have the 12mm 12pt its a common tool used on many american head bolts. Part# NBDM1212 $7.79

[jaybird840]

Porsche mechanic shop rate= $125/hr...... Factor of two for the dealership to make any money...... Wise advice from fellow pelicanites=priceless!!! Got the first three done in under five minutes. (Don't fret over the angle of the wrench.... I had to let it hang to do the photo )

Quote:
Originally Posted by KTL
Jaybird,

As far as removal, have you tried getting at the flywheel screws through the end of the yoke? My yoke is hollow so that's how I get to the flywheel screws on the stand.

[al lkosmal]

Nice 914. A stock CIS 2.7 will move it around pretty good, but your's is not stock. Based on the pistons you have in there, (definitely not CIS....a decent dome and valve cutouts, so i expect higher compression and E or S cams or the equivalent.) Check the pistons and cams for part numbers and post them so we can help you to verify what they are. somebody has been in there before and....who knows ....you may have the makings of a nice 2.7 hotrod engine which will seriously wake up your 914. Nice project....good luck.

regards,

al

[al lkosmal]

here's some 2.7 hotrod engine inspiration for you.
JE 9.5:1 pistons, E-cams, SSI's, Dansk 2in-1out sport muffler, Weber 40 IDAs
have fun with your project.....

[jaybird840]

Al,
Thanks for the words of encouragement.... The cams are marked

911.105.143.OR

and the pistons= Mahle 90 P 27 W2

Can you advise?

[jpnovak]

I think those are a 911S CIS cam from 74-77. The back of Wayne's book has an appendix of cam part numbers. They are not exactly taking advantage of those pistons valve pocket clearance.

[al lkosmal]

Yes, i would be glad to help. Others will chime in for the often required sanity check.

Cams = 74-77 2.7S cams (CIS cams)
Pistons = these may be the Euro 2.7S pistons...These are not high comp, (still 8.5:1), but are a nice upgrade over CIS pistons as will allow the use of some hotter cams such as E or early S....will have to check the Mahle p/ns and get back to you.

regards,

al

[jaybird840]

Yep,
Hotter cams are definitely in order. I will either be going with an "E" camshaft from John Dougherty, or Jamie Novak has a spare set of Crane 296 cams that have a profile that I like. With that said, I'm going to need to refurbish the rockers--who would you recommend for that? Which leads me to my next dilemma....

Split the case, or no? So far, the engine appears to have been gone through fairly recently. All of the wrist pins were snug with no noticeable wear. The crank spins very smoothly in the case, and there is no axial slop. Both CGarr and JPNovak have said that splitting the case may be more headache than it's worth. I'm doing the rebuild on the cheap, and this would definitely save both time and cash to leave it alone. Case savers are already done... Original oiling system (no bypass mod). Balancing is one of the things that still has me thinking. Can I just turn the flywheel, and hope that it doesn't throw things too far out of balance? If I can get through that issue, I probably won't split the case. As the car is a road warrior (3k-6k rpm), the balance issue may not affect me as much as a racer/AX'er.
The last concern is if I don't split the case, how do I get it clean? I guess it's either do it with rags, and try to keep gunk out of the inside of the case, or try to find a way to seal the cylinder registers in the case.... I guess I could slip the cylinders back in, and snug them up with sockets on the studs--that might do it. All your thoughts are warmly welcomed!!!!

[Dick Shift]

Yes! your pistons are Euro 8.5/1 cr. Good for carbs or MFI. Ck. to see that no more than .003 taper in cly's so you can rering.
CIS will work but my experience is the top intake boot will hold the 914 engine lid open @ 1inch. Another reason to go to carbs?
You need to get the CIS cam's reground anyway so get a mild carb grind, ie; "E" spechs.
Looks like you DO NOT have case savers from the picture. I recommend 2nd over size savers!
I also recommend Dow Corning 730 sealant for the head to cam tower sealing area's. ALOHA

[dtw]

Very hard to tell if there are inserts in that case. Can you scrub one really clean and take a good macro photo? Then we might be able to tell. If I had to pick, I'd say 'no' you don't have them.

There is really not any such thing as a rebuild 'on the cheap' on a 2.7 motor. You'll either pay now, or you'll pay later, but you'll pay.

I have a 2.7 that I bought as a finished zero-mile longblock. Turns out it was a pretty sloppily-done rebuild; I thought I would just tear it apart and re-seal it. Not so much.

Here's what a "$500 reseal" ended up costing:

pistons/cylinders $1,100
case work - 1st time $650
case work - 2nd time $650
replace case (1st one junk) $300
misc. machine work $300
rebuild heads $1,000
hard parts for rebuild $1,250
11-blade fan $175
upgrade alternator $175
backdate HEs w/good used $250
upgrade idler arms, valve covers, chain housings $250
install factory hardlines & aftermarket radiator cooler $1,000
repair and overhaul CIS $150
replace crank (found a nicer one though mine was good) $200
machine flywheel $70
replace starter $175
Grand Total $7,695

Nevermind the $1,000 on the 915 rebuild "while I was in there", or the $500 clutch pack...

[jaybird840]

Yes, If I haven't mentioned it before now, I have a set of Weber 40's that will go on the car... I'll scrub the base area on one of the studs, and take a good macro photo.

[J P Stein]

I rebuilt my 2.7L this past winter after 7 years of thrashing it at autocross......I did the build back then also.

I got a very nasty surprise. I had the crank turned to first under back then and split the case this time only to get at an oil leak on the #8 bearing. The innards looked lovely and I was a happy camper till I priced the rod & main bearings......good God!!!
The exact number escapes me (or I've blotted it out), but they were well over $1K, IIRC. Fortunately I has a couple STD/STD cranks and had both polished ($110), picked the best & got on with it.

Your pics show you have some kind of inserts on the case for the head studs....they look like case savers to me, but timecerts are a possibility. Either way, unless you have an overriding reason to split the case, I wouldn't fuss with it.

I got 198hp & 190 ft.lbs (after about 30 minutes of break in time) on a chassis dyno from the latest iteration.....and the motor seemed to pick up more power after 10-12 AX passes. Not a supercar (my 914 is a sows ear) but a very good AXer.

[dion914-6]

Jaybird, how about a better picture of the 'inserts'. Your pics look a lot like my 2.7 case, and I didn't think it had inserts.

Dion

[jaybird840]

Ok, here are macros..... Inserts or not? Maybe I'll post a poll... After examining several of them closely, I believe they are. It doesn't appear to me that they are consistent enough to be cast in that manner. I look forward to your replies!

[cgarr]

It may be just a helicoil type insert. A casesaver would cut further into the cylinder base sealing surface.

[al lkosmal]

Looks like you have timecerts to me. i've used them in two 2.7 rebuilds and they have worked well.

al