Ok, I am asking for hell fire...

[speedo]

Just bought an engine from a friend, an excellent builder (that does not frequent this board) that is a shuffle-pinned, boat-tailed, knife-edged engine. Fresh race build that was going to be crank-fired ETB. I will instead run twin-plug weber 46s. Carrillo rods and flame ringed heads..realistically, what does all this extra machining provide me. The engine is a SS 3.2. I was going to build up a 3.2 for a project using weber 46s... and this fell into my lap. The car will not be raced, maybe see some DEs. Car will be 1700lbs.

Speedo

[prschmn]

Bragging rights? Whatcha got for cams?

[boosted79]

boat tail, knife edge = 0 on a street machine

[speedo]

Cams are 171E149, GT3 pump, opened to 42mm, 10.5:1, built on a 78 SC case, deck height 020.

[prschmn]

Pretty strong cam for a street car. Not sure you'll be thrilled driving around town.

[speedo]

Originally Posted by boosted79

boat tail, knife edge = 0 on a street machine

I remember stating it will likely not be raced...didn't say it was just a street machine.
Price was too good to pass up. I was going to spend far more than what I paid to buy a core 3.2 and build it up. If it doesn't serve my needs...it can find it a new home. I was curious what it would have for me below 6000 rpm in a mid-engined chassis.
And as a plus...not racing it means I am likely not going to bend valves or need to be rebuilding it every year.

Speedo

[boosted79]

It sure won't hurt anything! I agree, most of the time a complete engine or car can be had for less than building one up yourself. You can change cams, etc to make it streetable for not a whole lot. You see cars and engines that had 150K "invested" and selling for a fraction. I remember that twin turbo that was in the "Reaper", he put 100k+ into just the engine and sold the engine for about 40K iirc after 4500 miles.

[speedo]

For my purpose, the other advantage of the 3.2 (vs a 3.6) is that it can be made to look original, like an early 2 liter engine with a honey colored shroud, webers and a twin plug dizzy.

Speedo

[Matt Monson]

Originally Posted by prschmn

Pretty strong cam for a street car. Not sure you'll be thrilled driving around town.

Speedo lives 10 miles out of town up a canyon; an amazing driver's canyon. He'll flog it appropriately. This won't be like the old 356 Carrera 4 cam guys who never gave the engine the kind of gas and revs they required to run.

Sounds like a fun project.

[racing97]

Are you sure .020 is the deck height you want to run?

[smokintr6]

I drove a 3.6 engine around on the street for a couple years that had a similar bottom end to your engine, and 3.8 RSR cams with ITBs. The biggest problem I had was trying to find an exhaust that would make the car bearable without stopping it up to the point that the cams made the package worse. With a reasonable muffler the sub 4k rpm performance really suffered and it seemed to take a whack at the top end too. With a big can B&B with B&B headers the car really screamed above 4k and did 300 RWHP on a dynojet.... but I hated the sound with the B&B. I eventually sold it to buy a stock 3.6, which in hindsight was a HUUUGE mistake, because I should have taken the thing apart and detuned it. At the time I didn't want to build an engine, but my stock 3.6 replacement ended up needing to be torn down to the crank anyway. DoH .... My engine also had Pauter long rods, which gave up one of the compression rings in exchange for a 7800 RPM limit (not useful with the muffler unfortunately) and a 50 hour run limit. Stay the course, keep the sweet engine. Detune if you have to, but maybe being mid engine will give you enough space to make a decent exhaust.

[speedo]

Originally Posted by smokintr6

I drove a 3.6 engine around on the street for a couple years that had a similar bottom end to your engine, and 3.8 RSR cams with ITBs. The biggest problem I had was trying to find an exhaust that would make the car bearable without stopping it up to the point that the cams made the package worse. With a reasonable muffler the sub 4k rpm performance really suffered and it seemed to take a whack at the top end too. With a big can B&B with B&B headers the car really screamed above 4k and did 300 RWHP on a dynojet.... but I hated the sound with the B&B. I eventually sold it to buy a stock 3.6, which in hindsight was a HUUUGE mistake, because I should have taken the thing apart and detuned it. At the time I didn't want to build an engine, but my stock 3.6 replacement ended up needing to be torn down to the crank anyway. DoH .... My engine also had Pauter long rods, which gave up one of the compression rings in exchange for a 7800 RPM limit (not useful with the muffler unfortunately) and a 50 hour run limit. Stay the course, keep the sweet engine. Detune if you have to, but maybe being mid engine will give you enough space to make a decent exhaust.

Good points.
Exhaust will not be a problem. The car currently has a custom exhaust which was designed for a hot 3.2-3.6 engine. Unfortunately no heat exchangers, but on the flip side the car won't have AC either... I live at 8200 ft. My AC will be very manual

Speedo

[Steve@Rennsport]

The modifications you mentioned are optimized for engines that are operated over 7500 RPM. 171/149 cams are high RPM cams and require more static compression to make power. Plus, they do not run very well between 3500 & 5K RPM.

The more displacement you have, the "milder" they feel so making the engine into a 3.3 or 3.4 makes things more streetable.

JMHO, but 8K ft operation would suggest a turbocharged solution, however there are several big pitfalls that require serious resources to resolve. The very LAST thing I want at 8000ft are carburetors since they do not compensate for altitude anywhere near as well as EFI does.

[speedo]

Originally Posted by Steve@Rennsport

JMHO, but 8K ft operation would suggest a turbocharged solution, however there are several big pitfalls that require serious resources to resolve. The very LAST thing I want at 8000ft are carburetors since they do not compensate for altitude anywhere near as well as EFI does.

Steve ...noted. Thank you for weighing in. Funny, I have several carbed cars. I tune them all for my altitude. When I go down to the flats (5200 ft) or up to Trail Ridge Rd (12500 ft), I have never been disappointed with performance. To your point, no I am not optimizing performance...no doubt there. The early 911s were all carbed and they seemed to be able to tune them... "adequately" for altitude. I get that modern EFI will compensate far more accurately that a carburetor designed 60 years ago.

In all fairness, it would seem appropriate to come clean on my application at this point. I will be running the 3.2 in a Beck 904. The 904 is offered as a roller, or as a turnkey with a 3.6 and as such...the 3.6 would seem out of place as might an EFI engine. A turbo in a 1700 lb car might actually be... "over the top". As I don't have a four cam carrera engine to install, the next best thing (to me) would be a standard looking six with webers. I can plug in an early 2.0 engine up to a 3.2 with carbs and look fairly correct.

Hope this admission now makes sense. I would like accessible power, and an engine that looks like it belongs in the car. If the chassis and the engine don't get along, I have options. In the meantime, I will have power at my disposal should I choose to use it.

[Steve@Rennsport]

Ahhhh,...so noted.

Personally, I would install PMO throttles (they can be made to look like carbs), and a milder cam (such as a 120/104) for a better powerband without losing the revviness.

Carbs jetted for altitude run dangerously lean down low so monitor AFR's to prevent buying very expensive parts.