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.....

http://forums.pelicanparts.com/porsche-911-used-parts-sale-wanted/641505-fs-97mm-ross-pistons-cylinders.html

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.

You're addicted to that laughing gas, aren't you. :)

I just threw that in there ;) I probably won't put it on this engine, I think it'll move with the 3.0 to the roadster. it's just too much parasitic weight for this car.

Sure, you say that now...:)

bottom end together. next, check deck height and C/R.

http://forums.pelicanparts.com/uploa...1325835941.jpg


http://forums.pelicanparts.com/uploa...1325835959.jpg


http://forums.pelicanparts.com/uploa...1325835996.jpg

Lvn it

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




http://forums.pelicanparts.com/uploa...1339539129.jpg


http://forums.pelicanparts.com/uploa...1339539148.jpg

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.



http://forums.pelicanparts.com/uploa...1340560267.jpg

http://forums.pelicanparts.com/uploa...1340560317.jpg

Great photos!

Thanks for posting your engine build.
Keep up the good work :)

Regards,

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 :rolleyes:

a 13 inch intake run should help out the torque.

http://forums.pelicanparts.com/uploa...1363420285.jpg


http://forums.pelicanparts.com/uploa...1363420344.jpg

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.

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.

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 ;)

Much like many of the things that happen in the search for performance, theory and reality often travel different paths.

There is no way that a properly tuned set of 46 will challenge your performance at any rpm range. Volumetric efficiency is enhanced when the fuel delivery system is properly sized for the proposed build.
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.

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.

Just trying to help.
Cheers

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.

I made these up. used some spun aluminum stacks I found on ebay and the bottoms are cut down regular weber stacks. friction fit together with a little epoxy for good luck.

power increase? no idea, if any. but they're pretty cool :cool:

http://forums.pelicanparts.com/porsche-911-technical-forum/576675-made-my-own-bell-end-velocity-stacks.html

Thanks for the info on the air horns- yes they look good :) All the best with your hot rod build.

Don,
I am digging it. What are you doing for air filters?
Al

planning on screens for the horns, with an optional foam filter on top.

Don,
Shy away from the teaballs (I mean the screens made from real teaballs). A couple of the knowledgeable locals (Jeff Higgens & Chris Nielson) mentioned that they had issues tuning with those in place. I have some of them (I made them from Peet's teaballs) and I think that perhaps the screen is so fine in those that they are too restrictive.
However, i have used the domed, screen filters with foam, that I bought off the shelf and are specifically designed to be used as filters without any ill effects.

regards,
al

finally found some studs the right length. renault exhaust manifold studs, on ebay :rolleyes:

a couple more pics for fun. manifolds are ready for grinding to port match the heads. I was going to use some factory mag ones I had but there's quite a difference from the pmo ones.

on the outside bores the stock ones have a real sharp jog outward. the pmo ones have a much longer/smoother change in direction.

pmo it is.

http://forums.pelicanparts.com/uploa...1367812621.jpg


http://forums.pelicanparts.com/uploa...1367812670.jpg


http://forums.pelicanparts.com/uploa...1367812729.jpg

I edited my spacer comment.
In your case I guess it's easier just to have two longer threaded rods from crossbar to carbs .then linkage from tranny to belcrank still works fine Still with the height of the spacers and air horns are you sure it will even fit into the eng bay?
The clearance on a normal setup is pretty tight on the back cylinders. No way to get a carb syncroniser on them or filters.
If you are having fun ,that's one thing . If this is all in an attempt to get higher torque numbers then ...........
Not trying to rain on the parade but just like the 901 trans instead of a 915 bolted to a 3.0 just trying to save you time. Time better spent some where else.

well. it's been a long time but things are finally progressing. one thing about making your hobby your job. when you get home from work you're not always excited about doing more of the same.

buttoned up and in the car. sorting wiring right now and figuring out the auxiliary oil cooler set-up.



http://forums.pelicanparts.com/uploa...1389324246.jpg


http://forums.pelicanparts.com/uploa...1389324316.jpg


http://forums.pelicanparts.com/uploa...1389324417.jpg


http://forums.pelicanparts.com/uploa...1389324439.jpg


http://forums.pelicanparts.com/uploa...1389324459.jpg

looks great don... btw, some of the engine tin looks familiar... :-)
I hope your project turns out exactly the way you want...enjoy...bob

thanks Bob. so I got those tins from you? that was a while ago. I put them on every new engine.

they sure look like ones I had a while ago...carry on...you're doing great on the project...

hoping to fire this weekend. progress pics. I'm taking a bit of time to simplify and clean up the wiring. the toggles on the left are 'ignition on/off' and ' starter' switches. that way I can crank and start the engine from the rear. I think I'll put a switch for an engine compartment light in the last hole.

http://forums.pelicanparts.com/uploa...1389944165.jpg


http://forums.pelicanparts.com/uploa...1389944206.jpg

I think you'll find that the spacers do help a lot with your torque curve. My intake system is even taller than what you have. I have the tall PMO manifolds and 1.5 inch spacers. The torque picks up dramatically at 4500 RPM vs 5000 without the spacers. Short manifolds delay the torque curve increase even higher.

-Andy

thanks for the input, and encouragement. you're pretty much the first person to admit there's a benefit to what I'm attempting here. can you post a pic or two?

I would love to see the back to back dyno sheets that show the improvement.
During the IMSA days we needed to add 6 inches to the runner length to measure a difference. Your results are obviously different than ours.

at the suggestion of a local pelican I used the third hole for an indicator light to remind me I've left the ignition on. gotta say, it's extremely convenient to be able to run the engine from the back of the car.

http://forums.pelicanparts.com/uploa...1390023509.jpg

also picked up one of these to use as a master dis-connect / theft prevention :rolleyes:

at least it's keyed.


http://forums.pelicanparts.com/uploa...1390024120.jpg

IT'S ALIVE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!

no real issues. a little ignition trouble due to points that got badly arc-ed in my monkeying around during set-up. oil dumped 2 minutes after shutdown, looks good and clean. drain plugs are clean. a few chunks of gooey Loctite 574 in the screen but that's expected. did the cam break-in run and runs great. sounds wicked. can't wait to get it on the road. got a Bursch on there for break-in so I'm not too noisy. then change over to an M&K.

3.4 porsche engine first run - YouTube

http://forums.pelicanparts.com/uploa...1390089909.jpg

don,
nice......sounds good. always a good feeling when they fire up so well.

al

thanks Al. it is good feeling, and perhaps always a little surprise, when they fire. I borrowed the carbs from my 3.0 to eliminate one variable for start-up. if not for the points issue it would have been a flawless fire. I remember rebuilding a lawnmower engine in grade eight, and my fascination and feeling of accomplishment that an engine I had taken completely apart and put back together ran. still feels pretty cool.

now I just gotta get the car on the road.

Al, two words............. Can Am :D

you know you want to.

If you can find room in your budget, I would recommend the up grade 930 oil strainer. Part # 930 107 314 00 They help oil scavenging.
Use caution if you buy an aftermarket (Chinese) strainer. Some of them offer suspect dimensions.


http://forums.pelicanparts.com/uploa...1390162265.jpg
http://forums.pelicanparts.com/uploa...1390162282.jpg

never heard of this Henry. what's the advantage? more oil flow to the pump? less turbulence?

Don, thats a really clean install. Looks really sharp and sounds great.

thanks. come up this summer and take it for a boot.