Help me design optimal engine setup for my hotrod

[procan]

I am in the planning stages of building/installing a new engine on my '69. It currently has a 2.0 '69 911E motor (not numbers matching), and I'm looking for more power.

Here are the Basics of what I am looking for:

1. I want to throw in a 3.2 w/ PMO's. I have decided against ITB's w/ EFI because I want the old school vibe, and I don't like dealing with electrical sensors (I'm a mechanical engineer who hated his electrical classes...electricity is black magic as far as i'm concerned, I like purely mechanical things).

2. I would like to rebuild and toughen up the 3.2 engine I get. I am contemplating replacing the camshaft, pistons/cylinders, headers, etc. I'm toying with the Idea of bringing it up to a 3.4-3.5, maybe, bringing me to my next point...

3. I do not want to cut out my fender flares and install wider ones. I enjoy the fact that I have a solid '69 who's body has not been butchered. I'm pretty sure the widest rubber I can fit in the back are 225's. Correct me if I'm wrong.

SO BASICALLY I need to figure out:

1. Largest displacement/hp suitable for limited rubber in the back.
2. Compression (Twin plug or not?)
3. Suggested engine internal replacement stuff
4. Size of PMO's (46mm, 50mm)

Application is mainly street. Looking for low end/ acceleration. Occasional DE and autocross.

[HelmetHead]

Lots of discussion regarding this in the engine rebuilding forums. Keep in mind If you go twin plug you will add at least $2K to the cost of the build (machining, distributor, wires, etc, etc)

[304065]

What gearbox? Very dangerous to try to mate your 901 to a 3,2. Particularly if you want low end acceleration for AX-- too much power in a 901 will pull first gear right off the end of the shaft.

There's a good reason why the factory started flaring the fenders with the 911R, S/T and RS. It's hard to use all that power. You can have some 911R -49 offset wheels cu$tom made, but the extra inch of rim width is on the inside, narrowing the track, not widening it. 225 is the widest rubber, but it will require very precise control of the wheel offset/spacing, rolled fender lips, lots of negative camber, clearancing of the springplate bolts and relocation of the oil line on the inside. All possible.

Next: What CV axles do you propose to use? LWB 69 used four M10 screws and two roll pins.

I'll let the others chime in here.

[procan]

I posted here instead of the engine rebuilding forum because this forum gets more traffic, and the same people.

The gearbox is a 915. In regards to CV, I haven't given that a lot of thought yet. I just started tearing down my car. This is one of the reasons I am trying to plan my engine so early, so I can address all those issues during my rebuild.

Also, if 225's are pushing it, maybe I'll settle with 215's? Should I just go with a 3.0 instead? I want a well balanced car. I spoke to a few people in my PCA section, and the consensus seemed to be that 3.2 was about as big as you wanted to go.

I am not set on twin plugging. If my compression requires it though, I will.

[Craig T]

Reading your post felt weird, almost like plagiarism. It is close to verbatim to the email I wrote Allan Faragallah at Aase Motors when planning the motor for my hot rod. I had the exact same desired result and the exact same concerns e.g. fitment, resistance to finicky electrical ECU's, etc.

I live at sea level and the local Santa Monica Mtn canyon runs never get above 3,000 ft, so altitude won't be an issue with the carbs (the first objection from the ITB and FI tuners).

The motor went in on Friday and I pick it up running tomorrow

I started with a good 3.2 core in need of a rebuild. I paid $3000 and it came with two-step SS headers. We went to a 3.4 liter, 10:3.1 compression, twin plug, with 46mm PMO, and all the stronger race motor parts. The exact motor you are describing.

PM me for a phone number if you want to talk about the cost and the build.

[Craig T]

I have SC flares that are rolled and just slightly reshaped by John Esposito. With Fuch 7" and 8" 15's, I managed to fit Toyo R888's in 235 and 225 without any problem. The fronts rub at full turn, but just lightly.

I did beef up my 915 substantially to handle the extra power. The clutch too.

[procan]

I started with a good 3.2 core in need of a rebuild. I paid $3000 and it came with two-step SS headers.

Where did you get a 3.2 core for $3K?

Also, I swear I didn't hack your email

The main thing on my build is I want it to look pretty stock on the outside, but mean on the inside. If the widest rubber I can fit comfortably in the back is 215-225 with my stock flares, then I don't want to overdo the engine.

[Craig T]

Originally Posted by procan

Where did you get a 3.2 core for $3K?

If the widest rubber I can fit comfortably in the back is 215-225 with my stock flares, then I don't want to overdo the engine.

The core was not running, and absent of all fuel inj, electrical, and other components. It was my old race motor. I sold my race car to a guy that miss-shifted down instead of up on one of his first race starts, causing a terminal mechanical over-rev (easy to do with all the noise and confusion). Goodbye rod bearing! Rather than rebuild, he went in a different direction and sold me the motor back.

Don't want to overdo the engine??? Do you know when you have enough horsepower? It's when you can break the tires loose exiting a corner and they don't stop spinning until you hit the brakes at the entrance to the next corner

[al lkosmal]

I was checking out nice 3.2 configurations in Wayne's engine book and the bump to 3.4 with 98mm Mahle P&C's, keeps the compression ratio to 9.8:1 or so. No twin plugging required. The 46mm Webers/PMO's and S-cams would make this a great, fun engine. However, I am not sure of the driving characteristics of the s-cam in this size engine, so I would look at E-cams too, to see which provided the best torque curve in this engine.

Currently, I have a stock 3.2 w/SSI's and Triad 2in-2out muffler in my 73 and it is a hoot. Plenty of grunt low down and throughout the range. But, I do have Carrera flares on the rear and I'm running 225/50/16x7 front and 245/45/16x9 rears. I am looking at this bump to 3.4 as my winter project..........with ITB/EFI, though i dig the carbs too.

regards,

Al

PS: Don't forget to consider the suspension and brake mods that may be required/desired to take advantage of the added power.

[Charles Freeborn]

Sounds like you've got your mind set on using a 3.2 as the platform.
Were it me, I would also retain the narrow body, but I'd go with a 2.7 re-worked to RS specs, or beyond. Something along the lines of what Supertec builds. For the kind of money you're committed to spending you can build an entirely reliable engine.
It may not be as fast, but it will be quicker and much more nimble due to the lower weight.
Just my .02¢

[Craig T]

I agree that the super 2.7's like the ones Supertec are building sound great when they rev to those high RPMS. There is nothing like that sound. They are a few pounds lighter, but not as much as you'd think, certainly not more than the difference of 1/2 a tank of gas. But, for a street car do you really want to be riding on the pipe all the time to feel the engine's real performance zone.

Low-end torque is the most usable power for a street application. Torque comes much easier with cubic inches. If you've ever driven an early car with a 993 Varioram you'll know what I'm talking about. If you don't like the look of a 993 motor stuffed in there, then a 3.4 build on a 3.2 or 3.0 with PMO's or ITB is a great compromise.

[RWebb]

I'm not done building the thread but am pretty ok with the motor, so read thru this:

Yet Another Boring Hot Rod Rgruppe Car - Part III, Powertrain

[procan]

Thanks RWebb, that powertrain info is awesome. Just the kind of info I was looking for to help me make some decisions.

[Craig T]

Originally Posted by RWebb

I'm not done building the thread but am pretty ok with the motor, so read thru this:

Yet Another Boring Hot Rod Rgruppe Car - Part III, Powertrain

Fantastic thread RWebb, thank you. I just finished and thoroughly enjoyed reading it, especially the interjections of humor. A bonus...It validated my decision do what I just did.

[RWebb]

so you are going with an Al case motor (like I did)?
- I like the 3.2L for the oil pump, heads with good flow, chain tensioners, etc.
- you can sell off the induction system to recover a little of the extra money you spend over a 3L SC motor

people will love seeing the stages of your build, so post pics as you go

[procan]

That is the direction I think i'm planning to go, although I kind of want to get an estimate beforehand on max hp and torque numbers for 215's-225's in the back. Anyone have an idea?

[haycait911]

I'm a big fan of the 3.0 as a basis for a build. a good low priced starting point. I'm building a 3.4 right now but lots of little headaches and cost. the next one will be a 3.0 again. an easy 250hp on carbs and cheap to build. and freakin' bulletproof.

core 3.0 plus JE pistons plus a pair of cams plus webers plus exhaust = 250hp.

3.0 dyno day - a pleasant surprise

did I mention bulletproof

well...at least it didn't go BOOM..BANG...BANG...BANG...

[procan]

I'm a big fan of the 3.0 as a basis for a build. a good low priced starting point.

All the 3.0 powerplants i've seen have been the same price as a 3.2. Maybe I'm looking in the wrong places.

[haycait911]

Originally Posted by procan

All the 3.0 powerplants i've seen have been the same price as a 3.2. Maybe I'm looking in the wrong places.

the last 3.0 core I bought had a bad crank but all else was good, a '78 big port engine complete, for $1000. I like the idea of the 3.2 'stroker' over the 3.0 but we're talking a very small difference in displacement. I'd buy whichever one fell in my lap first.

also I've had good luck with webers. never had problems setting them up.

[procan]

A fellow local PCA member is giving me a deal on a 2.4 that I can't pass up. I'm going with the 2.4 with the possibility of bumping it up to a 2.7 complete with PMO carbs and headers. The 2.4/2.7 is more of a period engine, and I think the low end of the 3.2 is enough to get me in trouble.