engine gurus help please!!!!

Ruff1 · 03-30-2006, 07:17 PM

I am rebuilding my engine by my mechanic and he is going to use 2.7L parts on my 2.4L 1973 911 motor. He said it will be very fast and will be faster than a 3.2L motor please give me your opinion here is the quote:

set 2.7L P&C's (used) $500
pair SC cams (used) $250
set 2.7L intake (used) $200
carrera tensioners (used) $400
carrera oil pump (used) $300
new bearing set (all) $300
gasket set $200
chain set $125
clutch $500
head work valves, porting $500
case work-insert,open ,deck, oil bypass $500
set powdercoated sheet metal, fan $200
25 hours re&re engine, clean, tear down, reassemble $1875
(at $75 an hour rate)
total---------------------------------------------------$5850

is this resonable and will my car be fast i dont know much about porsche engines it will be my first one being built?

Mr9146 · 03-30-2006, 07:58 PM

Looks like you're getting the deal on case machining.

Jim Sims · 03-30-2006, 08:19 PM

What type of '73 motor are you starting with? CIS or MFI?
I don't see checking and polishing crankshaft, rebuilding connecting rods or rocker arms or re-facing the flywheel. Nor do I see new chain ramps or connecting rod bolts. Is this engine already apart? If so, what are the condition of the chain sprockets? What is being done to adapt or upgrade the carburetion or fuel injection and oil cooling external to the engine? Are the cylinder sheet metal baffles being trimmed? This is also a good time to replace all the fuel, vacuum and vent lines plus clean-up/restore the engine wiring harness. I suggest you purchase Wayne's Porsche 911 engine rebuilding book and educate yourself further before proceeding.

afterburn 549 · 03-30-2006, 08:36 PM

Hmm, as for me I would never put in a used pump-maybe pistons but not used rings...and where is the cylinder re chrome (nikosol)? no one here wants to knock ya but you asked. A mag case might oughta be dowel pinned too. Line bore /over size bearings ..new exhaust valves...and I dont see where the "fast" is coming from.. SC cams will be better..loose 500lbs will really help. The mag case will absolutely need line bore and O.S mains..the bearings alone are at least 400.00 ( I know)I am thinkin you need to reload this picture b4 you open your wallet or you will do it twice if you cut to many corners and that wont be cheaper. To do a quaility eng. parts and machine work will run ez 5000.00 not counting Rand R and dwn and back togather.

Ruff1 · 03-30-2006, 08:52 PM

i am starting with a 1973 2.4L with cis. The engine is good im driving it know but it smokes when i punch it and the valves are ticking loud!

Jim Sims · 03-30-2006, 09:00 PM

If a '73 CIS then it will also need new fuel injectors (or a least a correct set of used ones) and either different heads or further head work in the injector area; the '73 CIS fuel injectors will not work with a 2.7l CIS intake manifold.

Jim Sims · 03-30-2006, 09:05 PM

Buy and read the below referenced book; it will likely save you hundreds if not thousands of dollars and a lot of grief.

http://www.pelicanparts.com/catalog/ShopCart/BOOK/POR_BOOK_bkptec_pg3.htm

Jeff Alton · 03-30-2006, 09:43 PM

Well, just looking at he parts list I am not sure how it will be "faster than a 3.2" which has better fuel injection, the same cams and roughly 15% more displacement. You need to make sure the "uesd parts" you are getting are in spec for sure. I don't see any rings on your list either... The price seems fair enough but what if the heads need new valves? are you prepard for that extra expense for example?

If you want to chat offline about this, feel free to hit the email button beside my user name or send me a PM. I have a pretty good idea who is quoting you......

Cheers

RoninLB · 03-31-2006, 03:52 AM

SC cams in 2.4 cam towers ?

ianc · 03-31-2006, 08:34 AM

Not sure what the going price is these days, but $400 sounds a little steep for USED Carrera chain tensioners as well...

ianc

Ruff1 · 03-31-2006, 02:15 PM

i was talking to my mechanic and he said most of the parts have about 10,000 miles on them!

Grady Clay · 03-31-2006, 02:27 PM

Just to check; your mechanic is in BC not LA and initials aren’t MM.

You are getting some good feedback here. I see some unnecessary things and others missing.

Best,
Grady

afterburn 549 · 03-31-2006, 03:18 PM

If you want more pwr..(who dose not) now is the time to think about it as the labor is the same....use the $$ to your advantage....think.. think ..dwn the road here..twin plug ? higher C.R.?? If your going to buy pistons -CIS is not your best choice for power as they are in the way and 8.5 r.a. Just a thought from us that care,, dont want you in the world of "wish I had known that "" Cis can be made more better, is a good reliable sys (better then carbs) but a true stand alone I would think about....even if its dwn the road prepare the way now. Some will say go carbs- Mostly cause they worked real well but today's electronics is the way to go.(carbs are pesky lil aminals that belong in museums)LOL... I get the flak for that. T.m.O.- and I calls em as I see em-

RoninLB · 03-31-2006, 04:02 PM

Quote:

Originally posted by Ruff1

set 2.7L P&C's (used) $500

I ran forged 2.7 RS 8.5 pistons in a CIS instead of cast 2.7 CIS pistons for 40k miles without any problems. Passed smog no prob. Cast CIS pistons wear relatively faster imo.

RoninLB · 03-31-2006, 04:14 PM

Quote:

Originally posted by Ruff1
2.7L parts on my 2.4L 1973 911 motor.

He said it will be very fast and will be faster than a 3.2L motor please give me your opinion here is the quote:

pair SC cams (used) $250

is this resonable and will my car be fast i dont know much about porsche engines it will be my first one being built?

I really don't understand your mechanic's logic on this one? I'd ask for an explain on this one.

It is possible to build a faster 2.7 street engine than a stock 3.2. I have one and it's been confirmed by 3.2 hot rod guys.

My carb gas millage is about 2/3 that of a CIS.

afterburn 549 · 03-31-2006, 04:42 PM

OH believe me its possible as long as the other guy is not building his to beat yours. All things being equal the bigger displacement will Winn...but all things are never equal. My 2.7 will beat lot of 3.2 and bigger...but wont beat them all....depends whats been done . A hot rod is more then bore and stroke ..pancakes are more then flour and water.

Mr9146 · 03-31-2006, 04:54 PM

The problem with threads like this is you have an innocent guy asking an innocent question and getting a thousand different answers. He doesn't know who to trust when the person he should be trusting is his mechanic.

I'm starting to see a problem here - too many chiefs and not enough indians.

Hey, Ruff1, do yourself a favor and go with your gut. There's a thousand ways to skin a cat, and if you have faith in your mechanic you'll probably come out just fine. Just have faith and don't put too much stock in what you hear on this board ... read with skepticism and not blind loyalty. Hopefully you did your homework on the mechanic doing the work.

RoninLB · 03-31-2006, 05:51 PM

Quote:

Originally posted by afterburn 549

OH believe me its possible as long as the other guy is not building his to beat yours.

my writing is "stock 3.2"

afterburn 549 · 03-31-2006, 06:00 PM

Well in a hoff I go

Zeke · 03-31-2006, 06:39 PM

Not an expert here by any means and I have to agree with Mr.9146. Just wondering, if you bring cams from another motor to this one, shouldn't one send the cams and rockers out for a quick refacing?

Also, someone 'spain to me the used intake runners, etc. Is the 2.7 CIs stuff larger? I see PET shows early 2.7 throttle at 56 mm and later at 63. Maybe I don't read that right.