Anothe quesiton: V8 Conversion?

[350HP930]

Think about the guys who spend $25000 on a 500hp Turbo upgrade/rebuild....how much of that do you get back? How about a twin-plug 3.7L?

My 500+HP upgrade/rebuild is costing me less than $9K, but thats because I'm a cheap DIY bastard.

[kaisen]

I think if you went to Andial or Powerhaus, et al, you'd be in a little deeper

E

[ficke]

Kaisen brought up good points, maybe I am living to much in the past. I played with BBC's in early 80's (pro stock) then I put togeather a Mclearen F-5000 car in 1985 for a freind with a SBC. We had to buy a set of Webber's for the SBC and they were $5000.00 a set of Webber's for a 911 at the time were under $2000.00. We converted the Mclearen from a M10A to a m10B which was mainly dry sumping to lower the CG (and it also kept oil pressure around the whole track) The Tilton dry sump pump was $800.00 (Chevy did not make one for there engines at the time) 911 dry sump pump was $350.00, also the oil tank, lines cooler etc that comes factory on a 911 is big buck after market parts for a chevy at that time. The owner paid $5000.00 for a buildable core engine from Traco in 1975. In the 80's you had to pay a machine shop big bucks to make a sbc live at high HP out puts. Those SBC siamese exhoust ports cracked iron heads and warped alloy ones under stress. valve float with push rod engines make the tenshener problom 911 have seem rather tame. It is tough to compare apples to apples here and some people just do not care about alot of the advantages porsche gives its customers some people only need high HP #s . That is fine, I guess I am not one of them

[kaisen]

My 2001 LS1 (stock-shortblock 5.7L 346 cu in) 6 speed put down 373rwhp and in 60K miles I had no failures, no drops of oil on the garage floor, no valve adjustments, no plugs, rotors, or caps replaced. The A/C froze me out and never failed to work, and I got 25mpg at 74mph on cruise. Oh, and I have timeslips for 11.97 @ 122mph on street tires, and it lapped Brainerd International Raceway at 2:02, about as fast as 360 Modenas, Vipers, and 996TT's. That's in a 3400 lb car.

Just think of it in a 2400 lb car. Best of both worlds!

E

[snowman]

If you race a chevy motor like a Porsche motor can be raced, I mean all out racing on a road racing track it will break if it dosen't have all $25K worth of stuff in it. Otherwise why do ALL the nascar guys use this expensive stuff? All the VARA race cars (the ones that don't break) use all the expensive stuff and the ones that don't are swearing that they will next time as they are picking up the pieces. This includes all the Ford guys too. The corvett stuff works good for a few runs on the drag strip or a couple of laps but then it starts to break and when it does, ka boom. Sorry of you are one of those who dosen't beleive this but just start to track the car a lot, serious track time like a vintaqe race and you will soon see what I mean.

[kaisen]

Interesting observation, Snowman. I don't agree.

Racing in a competitive series, especially at the professional level, is all about cubic dollars. That competitive edge, however small, is worth the money. Race motors, by definition, are at the bleeding edge; the balances between power and longevity and weight and rules. That 'nth' costs a lot more than the one that came before it. It is an exponential equation. How fast do you want to go?

You used NASCAR. Series rules are stringent. Every hunderedth of a second over a 600 mile race can mean the difference between 1st and 23rd. Those engines are esoteric, not at all the 'stock-cars' that GM and Ford would like you to believe. Those motors live at 8500-9500 rpm, under load, pumping 800 horsepower, FOR 500-600 MILES a race. NASCAR Nextel Cup rules dictate that the rod/wristpin/piston combo can weigh no less than 1000 grams. I'm sure there are guys here that can do the math on piston speed and the G's they encounter. Of course they cost a lot of dough.

Try revving a stock 3.6L to 9000 rpm. Or a stock Corvette to 9000rpm. Both will leave expensive pieces.

But both will live 150K miles if kept under 6500rpm.

So making parts from 'unobtanium' may make the racing world go round, but if you're willing to back off a few 'nth's you can save a lot of dough and still be reliable, even on the track. It's about speed, not longevity....back off power 10% and it will live for a LONG time....over-rev it 10% and it will be shrapnel fast.

A low stressed 6.6L making 500hp will last longer than a high-stressed 3.6L making 500hp. Unless the 3.6L has high-tech, expensive parts (like the 6.6L would require at 800hp). Ain't no substitute for cubic inches, except cubic dollars.

Also, mass production brings an economy of scale compared to the racing world. GM will build 1.3 million 'LS' series engines (4.8L to 6.0L) this year and stick them in everything from Silverado to Grand Prix. Almost all parts are interchangable. Investment costs go down. That's how pretty 'trick' assembled LS6 heads retail for $750 a pair.

Another HUGE factor: Technology is getting cheaper. Today's mass produced engine management systems are more capable than any exotic F1 system from 1985. Fuel injection, coil-on-plug digital ignition, and all the advanced sensors allow a 2005 motor to make more power, burn less fuel, make less emissions, and last longer.

That technology is MUCH cheaper now, thanks to mass production. A 1985 Carerra is very low tech that way, but still expensive to replace or upgrade the sensors/electronics.

Even mundane things like engine blocks are better because of computers. Metallurgy, stress analysis, and CAD/CAM systems are making it easier and cheaper to make better parts. So even pedestrian GM cars and trucks benefit.

Again, the idea of 500 reliable horsepower in a 2400 pound Porsche appeals to me. The best of both worlds.

E

[safe]

Originally posted by kaisen
Again, the idea of 500 reliable horsepower in a 2400 pound Porsche appeals to me. The best of both worlds.
E

To me it won't be a Porsche without an aircooled flat six....
Put the chevy in a light kitcar, that would be fun!

[ficke]

if the Porsche engine is not the best choice why is the car?

[ficke]

Let me try to summerize, If you want to go fast in the lower classes , Chevy etc. is going to be cheaper than a Porsche etc. If you want a car with high performance features to run in the big events it is cheaper to go Porsche since the cars came from the factory (economy of production) with the go fast bits already. The old " Making a silk purse out of a sow ear' does seem to be true. I have to concead the porsche is more $$ compared to street Chevys becouse there is not a non- "race" option like the Chevy and in that street state size matters.

[kaisen]

Quick response:

Put the chevy in a light kitcar, that would be fun!

Yes, but Ultima GTR kits are VERY expensive. "Good" kit cars are. Why not start with a good 'depreciated' chassis like a 911/930 roller?

if the Porsche engine is not the best choice why is the car?

Because it handles great, is recognizable (it has aged well), has tremendous aftermarket support for lots of go-fast goodies, and I can't think of a worthy GM car that you can get to weigh 1900-2400 lbs.

To me it won't be a Porsche without an aircooled flat six....

So you don't like the Boxster, 996/997, 928, 944/968, Cayenne, 917's, or Porsche/TAG Indy cars? You're right, a V8 911 is no longer a true Porsche, but why is that the point?

If you want a car with high performance features to run in the big events it is cheaper to go Porsche since the cars came from the factory (economy of production) with the go fast bits already.

Didn't the Corvette C5R win LeMans a time or two? What are go-fast bits, exactly? What modern (2000-2005) production 911 has a go-fast bit that a similar vintage Corvette doesn't? If you can think of one (maybe dry sump lube), I'll bet it can be added to the Vette (although it isn't as necessary as you think) and still be cheaper than the 911. And since we're talking specifically and exclusively about ENGINES, it is so very much less true. Again, you can build a race-worthy LS1/LS2/LS6 V8 with all the go-fast bits for less than a similar 3.2/3.6/3.8. And if it only needs to rev 6500 rpm, it can be done for WAY less.

A 282hp 3.6L Varioram, USED, is still going for $10000+. For $10000, you could build a 6500rpm 282hp Chev V8 that would be indescructable in any form of racing. You could take that used 9K mile LS1 for $3000 and DE-TUNE 70 horsepower out, by lowering the compression ratio and destroking it (the 4.8L crank would do it) then lowering the computer's rev limiter to, say, 5500rpm. Then add all the 'trick' racing internals and valvetrain to handle 8000 rpm so if you missed a shift there wouldstill be a margin for error. Heck, you could even add dry sump lube to make you warm and fuzzy. It could run upside down when you rolled it. All for under $10000.

Let's have an open mind to ingenuity and evolution. Or do you like replacing points, adjusting valve lash, and rejetting carbs?

E

[safe]

Originally posted by kaisen
you don't like the Boxster, 996/997, 928, 944/968, Cayenne, 917's, or Porsche/TAG Indy cars? You're right, a V8 911 is no longer a true Porsche, but why is that the point?

Ok, I shouldn't be so narrow minded. An air cooled flat 4-12 is acceptable

Also I should have written: "To me it won't be a Porsche 911 without an aircooled flat six".

[350HP930]

I have a fetish for aircraft engines and dry sumps so the porsche flat six really appeals to me.

If you put a turbo and some loud exhaust on one they sound pretty badass too..

[snowman]

These guys with their under $25K chevy go fast stuff are just kidding themselves. Why do you thing Chevy makes Bow tie parts, you know the ones that cost about the same as Porsche parts do.

[kaisen]

Chevrolet makes Bow-Tie parts to adhere to racing rules, and update design and manufacturing for a series of motors that is up to 50 years old. Chevrolet doesn't make Bow Tie parts for the LS series motors (or the LT1/LT4 that preceded), just the 'old' small block platforms from 1956-1992.

Bow Tie parts are race specific. An example: some Bow Tie head castings are NASCAR legal and are 12 degree combustion chambers. To have the valves sit at that angle calls for a radical redo of the entire valvetrain geometry in an 'old' smallblock. That means it is really ONLY for that application. They can't make very many of them because of that, so they are more expensive.

But NOT as expensive as you must think, snowman.

The newest racing BOW TIE small-block (Part # 10051181) is only $1391 retail. The CNC NASCAR block machined for AN fittings and 2.64" crank is only $5250 (only diff is CNC machining).

You can't fit a big block in a Porsche, but the ZZ572 crate motor (572 cu in) comes COMPLETE with carb, intake, distibutor, water pump, oil pan, etc for $13895. That motor produces 720 horsepower and 685 lb-ft right out of the box.

The Corvette C5R aluminum block (not considered a 'Bow-Tie' part) is only $6191....this is the EXACT same Katech block that won LeMans. That block was only necessary to get 427 cu in due to its 'siamesed' press-fit liners which allowed a 4.125" bore in a 4.600" bore center (vs the sub-$1000 LS2 block has a 4.00" bore). C5R heads (PN:12480005) run only $1700/pr.

The C5R is exactly what I'm talking about. The 'nth'.

If you MUST have 427 cu in, you used to have to buy a $6191 C5R block (which is still cheaper than a new stock 911/930 case and a new set of cylinder barrels). But if you can live with 404 cu in, you can do it with an inexpensive production LS2 block. Heck you can get 427 with a stock 4.00" LS2 block and a $2000 4.125" stroker crank. Or there are companies (Darton) that will re-sleeve the LS2 block to 4.125" bore for about $2300.

It is racing rules that dictate a lot of parts combinations. That is what dictates their expense. There was a time when 2.8L RSR cylinders were 'unobtainium'. Now why not just start with a 3.2L production Carrera motor?

Snowman, I think your comments are uninformed. I heard that a Porsche Motorsports engine set-up for the '03-04 GT3 campaign ran in the $40,000 neighborhood.....I would defer to an expert to ask if that were true. I'm not just going to say: "If you race a Porsche motor like a Ferrari motor can be raced, I mean all out racing on a road racing track it will break if it doesn't have $40K worth of stuff in it. Otherwise why do ALL the GT3 guys use this expensive stuff? All those Porsche motors and their bad rod bolts and head studs and oil leaks. All these guys with their under-$40,000 Porsche stuff are just kidding themselves. Why do you think Porsche makes Motorsports parts, you know the ones that cost about the same as Ferrari parts do."

350HP930: A friend of mine had a Mooney in the early eighties that had a factory Porsche flat-6 motor. Said Porsche right on the engine cowl. I flew with him from the Minneapolis area to Bayfield, WI (Apostle Islands of Lake Superior) to crew on his racing sailboat...that was probably 1986.

E

[jluetjen]

If a 911 with a V8 conversion is SOOOOO good, why are they always worth less then a 911 with a 911 engine in it? I just don't see people lining up to buy 911's with these V8 conversions in them no matter how many HP they put out.

[beepbeep]

Hmm...as source of cheap torque/power, V8 is very efficient. However, there are other less obvious reasons why people buy this car. I believe some of them would be offended by pushrod V8 even if it's cheap to buy. While V8 is cheap to tune, doing a properly executed install in 911 isn't.

There are issues of extra weight (for iron-block ones), lost prestige (pushrod 50's tech in car known for technical excellence) and complicated install (hard to do watercooling right).

Please don't missunderstand me, me an Mattias are installing a non-Porsche engine in 911 ourselves, but it's more of a prank. Also, engine is light, quite hi-tech and it's a 4-banger.

[sammyg2]

LOL I used the exact same arguments in favor of the V8 in a Porsche, a few years ago before I actually built one.
Never again. I love my 911 with the Porsche engine, I did not love the Porsche I built with the V8 engine. I didn't even like it very much. I make excuses to drive my 911, i didn't do that with the V8 car. I would never, ever think about doing it again. It just didn't have the feel or the charm that makes Porsche a great car.

To get the real story, don't ask people who are thinking of building one, don't ask people who are building one now, ask people who used to own one, they will tell you what the car really is.

[snowman]

kaisen-- Keep dreaming.

[asphaltgambler]

When the time comes on my 635 I will put the LS7 small block (from the new Corvette due out this fall) and trans. The amount of $$ it will take to stuff a late 4.4 V-8 with all the mods or a M5 V-8 is too much. Current cost est for an LS7 engine w/electrincs is @$7500.00 I think that's a steal!

[snowman]

After you put that corvett engine in your BMW I challange you to 25 laps at Willow Springs Raceway, winner is just one who finishes all the laps, at best time you can do. THats with my stock 20 year old M635. Looser pays for the tow truck for the corvett engine.