Rebuild a 2.7L or 3.0L six motor, which is cheaper? Options

[Justinp71]

I'd also ask yourself what kind of motor do you want? A proper (right cams, timing, etc...) carbed motor is a different animal than fuel injected motor, imho.

I ran a webber carbed/cammed 3.0L for years (now rebuilt into a 3.2L), it was a blast of a motor. Good power/weight with the 914, sound was amazing too. Very reliable for me, seems like most sixes that don't have an old un-maintained CIS system are reliable. I drag raced a modern 6.0 GTO at laguna seca down the main straight and we were neck and neck.

Fuel injection would add mpg, smoothness and cleaner air. This is because the old IDA webber design requires a fuel mixture of around 12:1 at cruise to keep the idle circuits to operate smooth.

[jimkelly]

i'd sure like to see someone else do a mcmark style turbo 4.

http://www.914world.com/bbs2/index.php?sho...54&hl=turbo

[Mark Henry]

i'd sure like to see someone else do a mcmark style turbo 4.

http://www.914world.com/bbs2/index.php?sho...54&hl=turbo

(IMG:style_emoticons/default/hijacked.gif)
Not to be a dink but this is a discussion on the six.

[Mark Henry]

I'd also ask yourself what kind of motor do you want?

The other side of this coin is what kind of motor are you getting?

I've seen some real abortion builds out there.... (IMG:style_emoticons/default/dry.gif)

[jimkelly]

i hear you.

but i see it as a 175-200 hp thread, selective reading i guess (IMG:style_emoticons/default/smile.gif)

i am driving one of those abortions you are reffering too (IMG:style_emoticons/default/sad.gif) and i know it.

[Justinp71]

I have a supposedly decent 2.7 core...I'll need to do a leak-down test to see if it's worth messing with. It has all the signs of the PO's story of a rebuild. Came out of a '77, but is a '74 case with oil tensioners, 11 blade fan, 930 valve covers etc.

Even saying that, I'd probably like to start with a 3.0 case if I could get one for the same $...and a 3.2 for sure if I could find a good one for ~$8k.

Sounds like someone did some work on it, see if you can find evidence of time certs on the head studs. Someone told me that the majority of the 2.7's had to be rebuilt with time certs by now, as they didn't last long from the factory. Although my 2.7 was not rebuilt... (IMG:style_emoticons/default/sad.gif)

I would recommend fresh top end gaskets (reseal the chain housings and cam towers too) when installing a 2.7 (or any used motor). My old one leaked like crazy! Although I guess it could be a rabbit hole if you start pulling the motor apart. At least install new versions of the easy to access gaskets, then if it leaks you'll be more easily able to find the leaks.

[r_towle]

i'd sure like to see someone else do a mcmark style turbo 4.

http://www.914world.com/bbs2/index.php?sho...54&hl=turbo

(IMG:style_emoticons/default/hijacked.gif)
Not to be a dink but this is a discussion on the six.

i thought you did not give a (garage level of interest and stress)

(IMG:style_emoticons/default/confused24.gif)

[Mark Henry]

i'd sure like to see someone else do a mcmark style turbo 4.

http://www.914world.com/bbs2/index.php?sho...54&hl=turbo

(IMG:style_emoticons/default/hijacked.gif)
Not to be a dink but this is a discussion on the six.

i thought you did not give a (garage level of interest and stress)

(IMG:style_emoticons/default/confused24.gif)

(IMG:style_emoticons/default/huh.gif) Damn (IMG:style_emoticons/default/busted.gif)

[mb911]

I had a 74 2.7 pre thermal reactors with 50k on it in my conversion 15 years ago. I rebuilt the engine only because I bought everything new at a vw swap meet for 100 dollars (what a deal) it was more of while Ivan at it. The engine had no time certs so I was going to do that while I was at it. I bought the time certs and looked at the course threads of the time certs and looked at how they were only .010 or so from breaking into the spigots that I decided not to do it. Keep in mind I have built hundreds of aircraft engines and also many porsche engines as well so take this with a grain of salt but the only reason to put time certs in is to repair pulled threads not to give extra strength..


Flame suit on

[Justinp71]

OK from Wayne's Book (pricing is 15 years old?), machine work you would do rebuilding a 2.7 but not on a 3.0.

$495 Line Bore
$350 Install Time Certs
$130 Oil system bypass mod
$29 Case saver inserts

=$1004, say *120% for today's prices = $1205

Looks like it is cheaper to rebuild a 2.7.

BTW His total was $3,300 for all the machine work (includes valvejob, rods and crank recon, etc...)

Total parts and tools was $2,872 which includes $1,400 for p&c's.

Grand total = $6200
This is a complete rebuild, only large purchase hard parts were the p&c's. EDIT-This Grand Total is older pricing from Wayne's book, please use your judgement for current pricing.

Quick note on the timecerts- They seem almost mandatory to me? The 2.7 I had you could only torq down about half of the headstuds... the other half wanted to pull out.

[raynekat]

OK from Wayne's Book (pricing is 15 years old?), machine work you would do rebuilding a 2.7 but not on a 3.0.

$495 Line Bore
$350 Install Time Certs
$130 Oil system bypass mod
$29 Case saver inserts

=$1004, say *120% for today's prices = $1205

Looks like it is cheaper to rebuild a 2.7.

BTW His total was $3,300 for all the machine work (includes valvejob, rods and crank recon, etc...)

Total parts and tools was $2,872 which includes $1,400 for p&c's.

Grand total = $6200
This is a complete rebuild, only large purchase hard parts were the p&c's.

I'm going out on a limb here, but IMO there is vitually NO WAY you can do a "quality" rebuild of any 911 6 cylinder engine for $6200.
The prices in Wayne's book are very out of date.
Parts are much, much higher now.
Ever price a set of pistons & cylinders lately?
And easy $4-6k just there.
Depending on how
many parts are worn out, the picture just gets worse.
The big builders (i.e. Rothsport) will charge you $20k up to $30k to do a complete
engine rebuild.
There's a reason for that cost....and it's not all labor.
There is a lot of machining required, again quite expensive.

I think you're all kidding yourselves in this link.
Good condition, low mileage engines are rare as can be.
So now you're stuck with a rebuild on whatever condition engine you can fine.
To do a top end only is really a sketchy idea.
Add to this that most of us....even the mechanically adept....would be in over our heads with a 6 cylinder engine rebuild.
So much experience goes into the proper rebuild that the average guy is going to miss something during the process, and then you flushed a bunch of money down the drain.

Again all the above IMHO.
My takeaway.... rebuilding a 911 engine is not a trivial or inexpensive proposition, and not for the weak hearted.
But they are the best sounding automotive engine when done correctly bar none.

[raynekat]

One thing I forgot about if you're going to do your own engine work. There are lots of speciality tools you'll need....i.e. the cam wrenches, etc. All that stuff adds up fast You'll go through a couple thousand really quick on the necessary engine cradle, specialty tools, torque wrenches, etc, etc.

Wayne's book is very good at detailing all the tools you'll need for the various jobs.

[Justinp71]

I do agree it's not a cheap or easy task. There are several people that are mechanically inclined that have rebuilt their own motors on pelican. It's not easy but can be done. It's just the overhead cam's that create most of the complication, other than that its not too far off from a type 4. But I do agree it is a risk to build your own motor.

As far as pricing I think for the machine work +20% would be close, best to call your local machine shop to verify. P&C's can be rebuilt if you have nikasil's I bought a set from EBS for ~$2600. Crankshafts are rare and expensive, luckily you only need one if the old one was badly damaged. They are nitrided so they are very strong.

Another note it is another level of complexity to do the bottom end, I would be less worried to tackle just a top end rebuild than an entire rebuild. You can also do alot of the work yourself and have a shop assemble the bottom end for you. Top end is still complex, but you can take your time until you get it right.

Its also very labor intensive, like 80+hours. That I believe is part of the reason for the high rebuild costs.

Buy a core inspect it very well, add up the costs, if it ends up being too expensive just sell the parts off...

[jcd914]

Many machine shops are not going to be equipped to machine a 911 engine or won't mess with them (too much risk) and then there are some that you would not want to be doing your machining.

When Jeff had his 2.7 apart and took it down to Competition Engineering they looked over the parts and quoted him $7K just for machine work. He found a 3.2 in a 912 in LA for $7.5K (I think) and he had go down and pull the engine.

Jim

[0396]

i hear you.

but i see it as a 175-200 hp thread, selective reading i guess (IMG:style_emoticons/default/smile.gif)

i am driving one of those abortions you are reffering too (IMG:style_emoticons/default/sad.gif) and i know it.

Its only in your mind (IMG:style_emoticons/default/biggrin.gif). It could be a good build, but who cares its yours.

[0396]

OK from Wayne's Book (pricing is 15 years old?), machine work you would do rebuilding a 2.7 but not on a 3.0.

$495 Line Bore
$350 Install Time Certs
$130 Oil system bypass mod
$29 Case saver inserts

=$1004, say *120% for today's prices = $1205

Looks like it is cheaper to rebuild a 2.7.

BTW His total was $3,300 for all the machine work (includes valvejob, rods and crank recon, etc...)

Total parts and tools was $2,872 which includes $1,400 for p&c's.

Grand total = $6200
This is a complete rebuild, only large purchase hard parts were the p&c's.

I'm going out on a limb here, but IMO there is vitually NO WAY you can do a "quality" rebuild of any 911 6 cylinder engine for $6200.
The prices in Wayne's book are very out of date.
Parts are much, much higher now.
Ever price a set of pistons & cylinders lately?
And easy $4-6k just there.
Depending on how
many parts are worn out, the picture just gets worse.
The big builders (i.e. Rothsport) will charge you $20k up to $30k to do a complete
engine rebuild.
There's a reason for that cost....and it's not all labor.
There is a lot of machining required, again quite expensive.

I think you're all kidding yourselves in this link.
Good condition, low mileage engines are rare as can be.
So now you're stuck with a rebuild on whatever condition engine you can fine.
To do a top end only is really a sketchy idea.
Add to this that most of us....even the mechanically adept....would be in over our heads with a 6 cylinder engine rebuild.
So much experience goes into the proper rebuild that the average guy is going to miss something during the process, and then you flushed a bunch of money down the drain.

Again all the above IMHO.
My takeaway.... rebuilding a 911 engine is not a trivial or inexpensive proposition, and not for the weak hearted.
But they are the best sounding automotive engine when done correctly bar none.

Very true, price of admission for a great builder is 20 / 30 k these days.

[Mark Henry]

(IMG:style_emoticons/default/agree.gif)

But DIY can keep cost down especially on a stock rebuild.
But if you're thinking performance below will give you idea on what's involved with a hot street build. Be clear my engine is just a "mild" build, "wild" could double the cost...easy.


I'd say I have $11K into my engine, did all the machining myself (friend helped on some of the hard bits) except the rods and balance. Got my cylinders replated through LN. Waited for deals on some things and a trade on my carbs and dizzy so they would add another $3.5K.
BTW during the build I was cold offered $5K for the Mahle RS piston and cylinder set, my cost was $2600 for piston and plating.

I wouldn't sell it at firesale for less than $25K, really I doubt I'd sell unless it was an offer of at least $30K USD.
But then I have no interest in selling it, it's not for sale.

Below is the build list to give you an idea of what's involved and I 'd say I have more like 120+ hours labour into this engine.

Engine build sheet for 3.0 1974 914 six conversion

Engine 3.0L, 70.4mm X 95mm, 10.1: 1 CR, Twin Plug

Case, 1979, 3.0, serial # *6399XXX, 930/13, 930.101.104.4R, Supertec head studs
Crank, stock, std/std, polished and magnafluxed, converted to CW distributor drive gear
Rods, stock, rebuilt big and small end, new bushings, ARP bolts and nuts
Flywheel stock, with custom 914-901 adapter ring, CSP 228mm bus HD pressure plate
Full engine balance, pressure plate and adapter ring balanced separately
Main bearings, new glyco, DFL (Dry Film Lube) coated
#8 Main bearing, good used original Porsche, DFL coated
Rod bearings, new glyco, DFL coated
Intermediate shaft bearings, new Porsche, DFL coated
Gasket set, new nose and rear main seal, Supertec sealant kit
Pump, stock blueprinted and DFL coated , cooler stock 911 modified to 914/6 spec
Pistons, Mahle, new, 3.0 RS, DFL coated skirts, ceramic coated tops, Goetze rings
Cylinders, stock 3.0 nickasil, replated Milenium/LN engineering, stock gaskets, .025mm base gasket
Heads, 3.0 big port, minor port work, twin plug
Valves, stock size, exhaust new TRW sodium, intake new AE
Valve springs, Eibach race, retainers early stock, keepers stock modified
Ceramic chambers and exhaust ports
Cams, WEB-CAM, 120/104, set at 5.2mm/.10 lash, 964 cores modified to 901 spec
Towers, spray bars R&R, tapped and cleaned, rockers resurfaced, RSR rocker shaft seals
Chains, new IWIS, new cam sprockets, keys and pins
Tensioners, hydraulic, no fail modification
906 style cylinder cooling deflectors
Cooler, stock, 3.0, modified for 914


Carburetors, Weber 40mm IDA, rebuilt, new carb kits, 34mm venturies, 135 main jets, F3 emulsion tubes, 180 air correction, 55 idle, Ported stock manifolds, custom phenolic spacers.
K&N filters and rain hats, Weber linkage
Carter fuel pump

Distributor, Twin Plug, Patrick/Jarvis, CW, MSD internals, uses Jaguar XJS-12 cap (1989-1996),
Plug wires custom labled twin plug, Patrick Motorsports
Ignition, MSD 6AL, twin MSD high vibration coils, max RPM 6800
Spark plugs, NGK BPR5ES (BPR6ES also available for tuning)

Headers, 914, 1-1/2” MSDS, ceramic coated
Add the fan/alt, shroud, custom wire harness, etc...

Bought most of the parts 4-5 years ago when the Canadian buck was at par, start pricing that puppy out at today's prices and your butthole will pucker (IMG:style_emoticons/default/wink.gif)

[Mark Henry]

One thing I forgot about if you're going to do your own engine work. There are lots of speciality tools you'll need....i.e. the cam wrenches, etc. All that stuff adds up fast You'll go through a couple thousand really quick on the necessary engine cradle, specialty tools, torque wrenches, etc, etc.

Wayne's book is very good at detailing all the tools you'll need for the various jobs.

I've thought about doing a tool rental, I think I have just about everything except an early main seal installer, but it's likely not feasible because I'm in Canada.
Plus I have no idea what fair rates would be, plus deposit, a percentage for tool damage, insurance, etc.

[jimkelly]

boxsterfan,

what kind of max budget for engine rebuild were you hoping was realistic when you posted this thread?

what kind of budget you setting aside for related conversion parts and other general upgrades to accompany the more powerful engine?

aside from these, will you be paying for any labor?

everyone wants a six, no doubt, but many settle for suby or chevy power due to less cost, and in some cases more modern transaxles.

all the best with your car, looking forward to seeing it progress.

gas guzzling v8, sloppy trans, jim (IMG:style_emoticons/default/smile.gif)





quote name='boxsterfan' date='Feb 15 2016, 05:41 PM' post='2303525']
Which /6 motor is cheaper to rebuild? 2.7L or the 3.0L?

1. Assume core motor is in good condtion and no crazy findings when you tear it down.
2. Assume you are building the motor for longevity
3. You are putting this in a 914/6 conversion (was /4)
[/quote]

[Luke M]

I like Mark have built a 2.7 rs spec engine and currently doing a 83 3.0 for my brothers 914.
I can tell you this, my brother got a sweet deal on the 3.0. The po was upgrading to a 3.6 and the 3.0 was a running engine per the shop doing the swap. If you look around like we did there's deals to be had. With that said both engines had there fair share of problems. On the 3.0 it was resealed by the shop doing the swap and had pressure fed tensioners installed at the same time. I started to check the 3.0 over and figured I'd better retorque the head studs. That came to an end fast after I snapped off a lower stud. It did start to take the torque but it didn't feel right then snap. Long story short apart it came. So far the main difference in the two builds is the machine shop cost. My 2.7 had a linebore to standard , shuffle pins, case savers on all headstuds/case through chain stud/ trans mount studs, spigot faces machined flat, all that work was done at Ollie's machine ( go to their website to view the cost). That was not a cheap machine shop bill but it needed to be done. I had a local shop polish and inspect the crank, install new rod wrist pin bushings, and clean a few other misc parts. The same shop removed one of the snapped off head studs in the 3.0, polished the crank , inspected the rods, cleaned the case, cam towers, and chain boxes. Once the case on both engines where sealed up the prices seamed to be close on other parts. The 3.0 parts seam to be a little bit higher in cost. Both engines got replated nikasil cylinders and new je pistons. The added cost to the 3.0 came when we went to buy big port heads. They need to be sent out for a rebuild yet but total cost once done is $1300.00 on heads alone. Cams/rockers need to be sent out at a cost of $700.00. Based on what is or is being done on both engines the 3.0 is still well under cost of the 2.7. If I had to do it again I'd opt for a 3.0 for sure .
Both engines are getting the same induction, ignition, exhaust so the big expense comes down to machine shop repairs.