It is currently Mon Mar 30, 2015 6:34 am

All times are UTC - 5 hours [ DST ]


Forum rules


Please click here to view the forum rules



Post new topic Reply to topic  [ 11 posts ] 
Author Message
PostPosted: Sun Jan 18, 2009 1:16 pm 
356 Fan

Joined: Sun Jan 18, 2009 2:29 am
Posts: 3
Location: Hollister, CA
I am not well versed on either of these engines, but I have been asked a number of times if there are any differences between the two - serial numbers, pistons, accessories etc. not withstanding. If I were looking at the two, what differences are quickly noticable?
Thanks!
-Kevin


Top
 Profile  
 
PostPosted: Sun Jan 18, 2009 1:28 pm 
356 Fan

Joined: Wed Mar 26, 2008 11:45 am
Posts: 3957
Location: San Francisco
Kevin,

"I am not well versed on either of these engines, but I have been
asked a number of times if there are any differences between the
two - serial numbers, pistons, accessories etc. not withstanding.
If I were looking at the two, what differences are quickly
noticable?
Thanks!
-Kevin"

If the engine is complete, look at the tin, including the oil filler can. Most all of the tin in different in the 912's requirement for emission control and sealing to the larger engine bay. Take a close look at 356 engine tin and the differences are obvious.
Even if it's just a long-block, check the timing cover fasteners. The 912 used those for engine mounting, so the nuts had a female thread on the rear to accept the mounting bolts. They are also 'extended' so the engine mount clears the surface of the timing cover. 356s have plain, old hex nuts and they are 'below' the surface of the timing cover.
Thanks,
Ron LaDow

Post generated using Mail2Forum via email.

_________________


Top
 Profile  
 
 Post subject:
PostPosted: Sun Jan 18, 2009 1:32 pm 
The 912 third piece casting is much different and is held on by large shoulder nuts that are used to attach the rear motor mount cross bar. The 356 cover is held on by normal nuts.


Top
  
 
PostPosted: Sun Jan 25, 2009 10:00 pm 
356 Fan
User avatar

Joined: Fri Mar 28, 2008 12:15 am
Posts: 723
Location: Tucson, AZ
I think that if you look at the specs they are virtually identical except that the SC has a 9.5:1 compression ratio and the 912 has 9.3 or 9.25 depending on who you believe. The cam specs look to be the same duration and lift although I recall reading that the factory detuned the 912 engine to facilitate frequent and continued high speed runs (6,000 RPM) without grenading...perhaps fatter lobe flanks or the like??

STP

_________________
STP
Steve Proctor
Member Since 1977
VIN 84757


Top
 Profile  
 
 Post subject:
PostPosted: Mon Feb 02, 2009 1:13 am 
356 Fan

Joined: Sun Mar 30, 2008 2:30 pm
Posts: 19
Location: San Francisco, Ca
For the 912 engine to go into a 356, can the 4 shoulder nuts and associated studs still be used when the 912 rear mount is deleted? Or is different hardware necessary?

_________________
Randy Nonnenberg
1959 356A Coupe
www.bringatrailer.com


Top
 Profile  
 
PostPosted: Mon Feb 02, 2009 6:01 am 
356 Fan

Joined: Wed Apr 30, 2008 7:02 am
Posts: 208
Location: Washington DC Area
Randy,

If you are referring to the timing cover hardware, no changes are needed. The two bottom studs that locate the engine to the gearbox must be changed-912's are longer and can/will interfere with the trans.

Tim Berardelli

Quote:
Subject: [356Talk] 912 and 356 engine differences...
From: randy.nonnenberg@gmail.com
Date: Sun, 1 Feb 2009 21:13:28 -0800
To: 356talk@356registry.com

For the 912 engine to go into a 356, can the 4 shoulder nuts and associated studs still be used when the 912 rear mount is deleted? Or is different hardware necessary?

------------------------
Randy Nonnenberg
1959 356A Coupe
www.bringatrailer.com








HotmailĀ® goes where you go. On a PC, on the Web, on your phone. See how.

Post generated using Mail2Forum via email.

_________________


Top
 Profile  
 
 Post subject:
PostPosted: Mon Feb 02, 2009 7:17 am 
Tim,

I just used my first 912 engine in a 356. The studs did not hit the trans but did limit wrench choices and made it harder to tighten the nuts. Maybe some studs are longer yet? Using 356 studs definitely would be better. I did have a little trouble with the sheet metal piece that bolts between the timing cover(third piece) and the pulley. The cover nuts don't allow the piece to lay flat so it makes contact with the pulley. The sheet metal can re-worked or drilled for clearance.


Top
  
 
PostPosted: Mon Feb 02, 2009 9:25 am 
356 Fan

Joined: Wed Apr 09, 2008 8:20 pm
Posts: 839
Randy,
You can still use the shoulder bolts but the 356 breast plate
will need to be altered.
I have successfully milled off the bolt bosses etc to make the
912 'third piece' look and fit like the 356 cover. You will also need
replace the 4 912 case studs with shorter case studs...Lay the long
studs and shoulder nuts aside, don't throw them away.
I just altered a third piece cover for George Dunn....

Ken Daugherty
kend356@insightbb.com


-----Original Message-----
From: Randy Nonnenberg [mailto:randy.nonnenberg@gmail.com]
Sent: Monday, February 02, 2009 12:13 AM
To: 356talk@356registry.com
Subject: [356Talk] 912 and 356 engine differences...


For the 912 engine to go into a 356, can the 4 shoulder nuts and
associated studs still be used when the 912 rear mount is deleted? Or is
different hardware necessary?

------------------------
Randy Nonnenberg
1959 356A Coupe
www.bringatrailer.com




-------------------- m2f --------------------

To contact an administrator admin@356registry.com
To unsubscribe go to http://www.356registry.com/forum/m2f_usercp.php
Read this topic online here:
http://356registry.com/forum/viewtopic. ... 1093#31093

-------------------- m2f --------------------

Post generated using Mail2Forum via email.

_________________
Ken Daugherty


Top
 Profile  
 
 Post subject: 912 into 356
PostPosted: Mon Feb 02, 2009 9:52 am 
356 Fan

Joined: Fri Apr 04, 2008 10:38 pm
Posts: 468
I have probably popped over 50 912 engines into 356 Porsches. It is my favorite engine of this family. I am rather opinionated on this mod but I know Vic Skirmants is with me on this one as well. What I do is lighten the 356 flywheel to the 912 weight and put 28mm Zeniths jetted to C specs on in place of the Solex's. I only keep the Solex carbs if the original car was a Super 90 or SC which is fairly rare. 90% of the time we are replacing a 60HP normal that is tired. You cannot make a silk purse out of a sow's ear and it is foolish to destroy the originality of the original motor with a bunch of modifications and upgrades that will only cause it to explode sooner or later. I also fit a slightly modified 356 timing cover to the 912 engine so that there is no need for milling covers, altering tin [which you will deeply regret some day], etc. I like to add a Sport muffler and just for fun I bump the timing 2 degrees total. If you had a 60 and make this change you will think you died and went to heaven. Idles like a dream, very smooth, and un godly torque at midrange just where you really need it. Putting a new number on the 356 cover is fun too. Like P*BITEME*, P*2HOT4U*, P*UZ2B[original number]* or your birthday.
Image


Top
 Profile  
 
 Post subject: 356 vs. 912 differences
PostPosted: Mon Feb 02, 2009 11:14 am 
356 Fan

Joined: Sun Apr 20, 2008 12:54 am
Posts: 1818
The SC piston has a higher dome vs. the 912 providing the 9.5 vs. the 9.3 compression ratio as both use the same heads w/or w/o the extra holes in the '68 version for the air pump injections ('69 heads weren't drilled) and the smaller hole for some "wet" oil returning to the right head from the oil filler/breather--the left head is plugged.
Yes, the timing cover can be used as is for a 356, but possibly the 1/2-moon pulley plate might need some fitment depending which one you use (from a 356) and I have faced the 3-bosses to make the cover similar to the 356 (other than what's left of the 2-gusset
re-inforcement ribs) and exchange the 3-studs.
I haven't needed to exchange the 2-long suds on the case-to-the-transmission as they're difficult to remove; I just add about 12-14mm spacers so the nuts won't bottom-out on the unthreaded part of the studs--there's no interferance to the trans. case.

Dick


Top
 Profile  
 
PostPosted: Mon Feb 02, 2009 9:51 pm 
You can still use them just be sure you have a wavy 12 mm
washer under them.

Alan

Randy Nonnenberg wrote:
Quote:
For the 912 engine to go into a 356, can the 4 shoulder nuts and
associated studs still be used when the 912 rear mount is deleted? Or is
different hardware necessary?


------------------------------------------------------------------------

Randy Nonnenberg
1959 356A Coupe
www.bringatrailer.com <http://www.bringatrailer.com>




-------------------- m2f --------------------

To contact an administrator admin@356registry.com
<mailto:admin@356registry.com>
To unsubscribe go to http://www.356registry.com/forum/m2f_usercp.php
Read this topic online here:
http://356registry.com/forum/viewtopic. ... 1093#31093

-------------------- m2f --------------------


Post generated using Mail2Forum via email.


Top
  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 11 posts ] 

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: Bing [Bot], Google [Bot], Yahoo [Bot]


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
Powered by phpBB® Forum Software © phpBB Group