![]() |
|
|
|
Registered
|
time for a new engine build - thoughts and input appreciated.
my 3.0 is moving to the 'roadster' and I'm building a new engine for the '67 '912' .
here's what I have / where I'm at so far: - 3.0 case - 3.2 crank - I have JE 9.5 95mm pistons but I just picked up these..... FS 97mm Ross pistons and cylinders which puts me into a 3.4. I'll do a check on my engine to confirm CR. I may have to shave a little off the crowns to get below a 10:1 CR. - SC heads with intakes at 36mm - solex cams - 40mm weber IDS - M&K two in one out with headers ( and shhhhhhhhhhhh..... a 100 horse nitrous system ![]() that's it so far. I could certainly go bigger ports and a more aggressive cam but I'm all about the torque. any thoughts much appreciated. Don. |
||
![]() |
|
Max Sluiter
|
You're addicted to that laughing gas, aren't you.
![]()
__________________
1971 911S, 2.7RS spec MFI engine, suspension mods, lightened Suspension by Rebel Racing, Serviced by TLG Auto, Brakes by PMB Performance |
||
![]() |
|
Registered
|
|||
![]() |
|
Max Sluiter
|
Quote:
![]()
__________________
1971 911S, 2.7RS spec MFI engine, suspension mods, lightened Suspension by Rebel Racing, Serviced by TLG Auto, Brakes by PMB Performance |
||
![]() |
|
Registered
|
bottom end together. next, check deck height and C/R.
![]() ![]() ![]() |
||
![]() |
|
steves31
Join Date: Dec 2011
Location: maui
Posts: 57
|
Lvn it
|
||
![]() |
|
![]() |
Registered
|
slow going, too many other projects in the way.
had the pistons milled. I kinda guessed at how much to take off. I used piston pins to put one JE piston ( 9.5:1 CR ) between two of my Ross (10+:1?) pistons. put a straight edge across the two outer (Ross) pistons and measured the gap at the center (JE) piston. added a little for comfort and came up with 4mm. got the newly milled pistons back from the machine shop the other day and checked the CR today. came in at 9:1. pretty much what I was aiming for. a little low perhaps but safer considering decent gas is getting harder to find. around here only Chevron has 94 octane ethanol free. also checked deck height, with a .5 base gasket I'm at 1.25mm, seems OK to me. next, hone the cylinders. lap the valves, open head intake ports to 36mm. and get the cam towers on. here's the basics. - 74.4 crank - 98mm P&C's - 36mm intake ports - solex cams - 40 webers ![]() ![]() |
||
![]() |
|
Registered
|
got the pistons into the cylinders, serious pain in the *ss! the oil ring is a four piece assembly that doesn't want to stay in the groove so you can get the compressor on.
![]() ![]() |
||
![]() |
|
Registered
|
Great photos!
Thanks for posting your engine build. Keep up the good work ![]() Regards,
__________________
2002 Porsche Boxster S Cobalt Blue/Blk/Blk Crew Chief for Son's 1978 Porsche 911SC Original Porsche Mocha Brown 3.8L NASA race car Previous Porsches: 1958 356 Red Coupe - 1972 914 Blue -1972 911T Coupe Aubergine |
||
![]() |
|
Registered
|
it's been a while and slow progress but here's an update. time to install rockers and time cams. John D. ground me some 'big time bottom end torque' cams for this one.
mocked up the intake so I can start figuring out how to fit the engine in the car ![]() a 13 inch intake run should help out the torque. ![]() ![]() Last edited by haycait911; 03-15-2013 at 11:59 PM.. |
||
![]() |
|
Try not, Do or Do not
|
Two thoughts:
3 inch runner extension will offer little or no noticeable change in performance. When Chrysler (under the design leadership of David Long) experimented with extended intakes runner back in the 50s, the data showed a need for runner extensions of 32 inches or more to effect real change. Even VarioRam intake have almost three feet of runner change. If you insist on running spacers, you might find putting the spacers between the head and manifold will make the linkage easier to manage. Just my 2 cents. Cheers BTW: nice work so far, your project looks great.
__________________
Henry Schmidt SUPERTEC PERFORMANCE Ph: 760-728-3062 Email: supertec1@earthlink.net |
||
![]() |
|
Try not, Do or Do not
|
I just noticed that you're using 40 IDS carbs. They are way too small for this project.
The high speed enrichment never really lived up to it's potential so you should sell them the someone restoring a 67 S who will pay stupid money for them and invest in a set of 46 mm PMOs.
__________________
Henry Schmidt SUPERTEC PERFORMANCE Ph: 760-728-3062 Email: supertec1@earthlink.net |
||
![]() |
|
![]() |
Registered
|
thanks for the input Henry. I actually sold the IDS and am now using IDA's.
I see what you mean by the intake runner length. my 2 inches isn't much. but why are the 100mm tall intake manifolds so desirable? for the carb sizing, I'm afraid to go too big and lose my bottom end torque. I truly don't care what happens past 6k. I'll be doing a dyno on this engine and I'll make a point of swapping out the spacers. should be interesting. and in the end, it's just fun to play around. at least I probably won't put nitrous on this one ![]() |
||
![]() |
|
Try not, Do or Do not
|
Quote:
Quote:
The other issue is the function of the carburetors in question. There is little question that the modern design of the PMOs exceeds anything offered by the out-dated Weber design.
__________________
Henry Schmidt SUPERTEC PERFORMANCE Ph: 760-728-3062 Email: supertec1@earthlink.net |
||
![]() |
|
Registered
|
you've got me thinking Henry. maybe it's time to sell off a couple of sets of webers and spring for some PMO's.
|
||
![]() |
|
Try not, Do or Do not
|
Quote:
Cheers
__________________
Henry Schmidt SUPERTEC PERFORMANCE Ph: 760-728-3062 Email: supertec1@earthlink.net |
||
![]() |
|
Registered
Join Date: Sep 2005
Posts: 950
|
Haycait911, congrats on your interesting build. I sent you a pm on your air horns...but maybe it got misrouted. Thus I figured this posting, here are my questions: anticipated increase with these enlarged air horns and based on efficiency, where can one source a set?
Thanks for your time. |
||
![]() |
|
Registered
|
Quote:
power increase? no idea, if any. but they're pretty cool ![]() made my own bell-end velocity stacks |
||
![]() |
|
Registered
Join Date: Sep 2005
Posts: 950
|
Thanks for the info on the air horns- yes they look good
![]() |
||
![]() |
|
Registered
Join Date: Jul 2001
Location: mt. vernon Wa. USA
Posts: 8,713
|
Don,
I am digging it. What are you doing for air filters? Al
__________________
[B]Current projects: 69-911.5, Previous:73 911X (off to SanFrancisco/racing in Germany).77 911S (NY), 71E (France/Corsica), 66-912 ( France), 1970 914X (Wisconsin) 76 911S roller..off to Florida/Germany RGruppe #669 http://www.x-faktory.com/ |
||
![]() |
|