No seriously, V8 Swaps

[Brew]

Hm. Now you've got my curiosity raised in reference to a BMW V8 instead of an M30. I'm a big fan of the 4.0 v8, then and now, I'm just not sure what the cost, weight, power potentials, stock output, and fitment in an e30 are. Time to go looking, I guess.

I've personally worked on an e39 540 and an e38 740i, and didn't have much of an issue working on them, and I did the intake mani gaskets, oil separator (bitch to change) and a few other odds and ends. That is, however, in two much larger cars. I'm wondering how hard it'd be to do anything to this engine inside our cars.

As cool as it would be to have a M60/2 powered e30, it would take A LOT of custom work. Not worth it IMO, especially when you can drop in a S50/2 so easily. Then if you're dying for more power get a secondhand CF supercharger set-up.

I personally dislike working on the M60-series engines. Doing 2 sets of valve cover gaskets on X5 4.4i's in the last week will do that to you. I would imagine that it would be fairly difficult to work on in the e30 engine bay, too.

[StereoInstaller1]

I had to register for this one: the northstar doesnt have pushrods.

</rant>

Good call, Mr.Tom. Northstars aren't. I knew that too, was just being dumb.

http://members.tripod.com/~grannys/enginescadillac.html

Oops. But hey, welcome aboard!

Luke

[Insanity]

-So? They still weight less AND get better fuel econemy than a BMW v8. Who cares if it 'needs' huge displacement to get big hp? It works, yeah?

-Oh, btw, "ZO6 LS1" is an LS6; and its underated, not overrated.

They get better fuel economy because of a few reasons:

1) They're in a car that's simply lighter. A Corvette weighs a hellova lot less than a 5 or 7 series.

2) The BMW engine has a better powerband. More power means more gas, though. However, this is also why BMWs are ALWAYS faster than it would seem from their HP/weight ratio.

Additonally, the LS6 is only underrated if you're a bench racer who doesn't actually know a damned thing about drivetrain losses. 20% is a RIDICULOUS overestimate of drivetrain losses on most RWD cars. That's the only "proof" of underrating I've ever seen. Someone back calculating BHP from WHP by using an estimated drive train loss that's wrong.

Also, there are not a lot of NA BMW motors making 500 reliable horsepower.

Yes there are. Don't watch racing much?

BMW went to a V10 to achieve 500 hp.

So did the viper. Your point? V10 means nothing in and of itself.

The NON-Z06 LS2 is at 400 hp.

The LS7 is 500 hp.

Yes. Congratulations on stating the obvious. You will also never really get anything more out of those engines. Hence why they had to bump the LS7 to 7L, it's the only thing they could do to make more power.

Once again, I couldn't care less who MADE the engine. The point is that 4v/cyl on a big engine is ALWAYS better than 2, and not having pushrods is ALWAYS better than having them. Just look at the Corvette ZR1 with the LT5 engine. No OHV small block can even hope to touch what that engine is capable of, and it was made in america (well, even though the head was designed by Lotus).

[FredK]

2) The BMW engine has a better powerband. More power means more gas, though. However, this is also why BMWs are ALWAYS faster than it would seem from their HP/weight ratio.

Yes. Congratulations on stating the obvious. You will also never really get anything more out of those engines.

You're not gonna get too far on being a douche alone.

The LS1/2/6/7 have a pretty flat torque curve as well. I would not say one has a better powerband in comparison to the other.

You clearly know very little about GM engines. There is a lot of headwork that is possible with Gen III and Gen IV engines. Cams, CNC porting, etc. Yes, you can punch it out and stroke it as well, but headwork is key. Otherwise if your bottom end can't breathe, what's the point?

Please tell me how RADICALLY different the M60/2 and M62 are that you can look at it crooked and it will gain tens of horsepower. Also please feel free to detail the uber high technology that is available ONLY to BMW engines and not to the GM engines.

Yes, they don't rev very high, and that is why the HP numbers aren't in the stratosphere. In race trim these engines put out 600+ hp and the Corvettes aren't even in the same class as the BMW. They're in one class higher.

[boom-monkey]

I feel the reason you picked the sn Insanity is from the insane logic you use.

We're not talking race engines here. I'm talking totally streetable engines.

As I said in my other post, other than the BMW V10, which is no doubt a beautiful engine, name another NA BMW motor with 500+ hp.

Not to mention when you get into forced induction, the 'merican V8's still get them beat.

Plus they are still lighter AND easier to work on.

[Insanity]

You're not gonna get too far on being a douche alone.

The LS1/2/6/7 have a pretty flat torque curve as well. I would not say one has a better powerband in comparison to the other.

No, the BMW engines do have a better one, end of story. That's what variable valve timing/variable intake geometry and such does for you. Without that, everything is more of a compromise.

You clearly know very little about GM engines. There is a lot of headwork that is possible with Gen III and Gen IV engines. Cams, CNC porting, etc. Yes, you can punch it out and stroke it as well, but headwork is key. Otherwise if your bottom end can't breathe, what's the point?

LTs do have a lot of room for headwork, which basically brings them up to being a LS1/2. The LS2 is basically the end of the line though, you just can't get that much more out of the corvette LS1 or 2 engine without adding displacement, and chevy themselves know that, hence the C6 Z06 with it's 7L displacement.

Please tell me how RADICALLY different the M60/2 and M62 are that you can look at it crooked and it will gain tens of horsepower. Also please feel free to detail the uber high technology that is available ONLY to BMW engines and not to the GM engines.

Say it with me now:

Dual Overhead Cams.
4 Valves per cylinder.

And it's not only available to BMW, it's available to GM as well, and the one time they bothered to use it (the LT5 in the ZR1), they got better results than they ever did with the LT1. Plenty of companies make use of the mystical technology of dual overhead cams on large engines. You know, companies like Ferrari, Lamborghini and TVR, all of which make engines that are leaps and bounds above the specific output of a small block. Hell, even ford uses it with the ford GT, which will trounce a corvette(though, i guess it's not a perfect comparison, since the GT is supercharged). I already said I wasn't promoting BMW, or hating on chevy or anything like that, I'm just stating the simple and OBVIOUS fact that DOHC > OHV.

Yes, they don't rev very high, and that is why the HP numbers aren't in the stratosphere. In race trim these engines put out 600+ hp and the Corvettes aren't even in the same class as the BMW. They're in one class higher.

No. They are not. Regardless of what you do, the DOHC engine will always win in race trim. You simply cannot get the same power (or revability) from a pushrod engine. Why do you think F1 cars use dual overhead cams? Do you really think they could make 800 horsepower out of a 3L with only 2 valves per cylinder? Nope, not a chance. For one thing, you could never move that much air and not float the valves. For another, the valvetrain in an OHV engine could never hope to rev that high.

[Insanity]

We're not talking race engines here. I'm talking totally streetable engines.

You asked for reliable, I gave it to you. Endurance engines are extremely reliable. It won't become LESS reliable at a lower output, quite the contrary actually.

As I said in my other post, other than the BMW V10, which is no doubt a beautiful engine, name another NA BMW motor with 500+ hp.

In stock trim? Who cares? BMW uses their best engine for their performance cars, and uses the V8 for it's luxury offerings, not their all-out performance ones. The only time you'll see a BMW-made V8 at insane power levels from BMW themselves is in a race that has restrictions on the engines that can be used. For the street, they're just going to use the best they've got because there isn't a restriction. Does that mean the V8s are bad? Hell no. Just means the V10s are better.

[OLD323]

Im prepared for a bashing here but I just picked up a Rover 3.5 V8 and voices in my head (and mates) are all saying DOOO ETTTTTTTTT instead of the 2.7.

Its been done before, i like them for the fact that they are light, not stupidly torquey and the power standard would be similar to an M30 or worked M20 with the weight of an M10.

Thoughts?

[Streetspec_iS]

well, you know im down. starting to get over all the purist BS these days.

always been a fan of the Rovers since i saw one in 'RPM', pretty sure you know who i'm talking about Glenn.

The Rover 8s seem like such a decent choice, as you said

the fact that they are light, not stupidly torquey and the power standard would be similar to an M30 or worked M20 with the weight of an M10.

not sure how much experience these Seppo's have with them tho.

[FredK]

No, the BMW engines do have a better one, end of story. That's what variable valve timing/variable intake geometry and such does for you. Without that, everything is more of a compromise.

Yes, Vanos does improve the powerband, making the torque curve very linear. However, LSx engines, depending upon setup, are very flat in terms of torque output as well. The exceptions will always be the engines with highly hopped up cams.

LTs do have a lot of room for headwork, which basically brings them up to being a LS1/2. The LS2 is basically the end of the line though, you just can't get that much more out of the corvette LS1 or 2 engine without adding displacement, and chevy themselves know that, hence the C6 Z06 with it's 7L displacement.

The LS7 head flows 25% more than the LS2 head. The LS7 head has titanium valves, which helps it rev higher (7000 rpm redline) than the LS2.

Say it with me now:

Dual Overhead Cams.
4 Valves per cylinder.

And it's not only available to BMW, it's available to GM as well, and the one time they bothered to use it (the LT5 in the ZR1), they got better results than they ever did with the LT1. Plenty of companies make use of the mystical technology of dual overhead cams on large engines. You know, companies like Ferrari, Lamborghini and TVR, all of which make engines that are leaps and bounds above the specific output of a small block. Hell, even ford uses it with the ford GT, which will trounce a corvette(though, i guess it's not a perfect comparison, since the GT is supercharged). I already said I wasn't promoting BMW, or hating on chevy or anything like that, I'm just stating the simple and OBVIOUS fact that DOHC > OHV.

I don't disagree that DOHC has more potential for higher revs and higher specific output per unit displacement. I am just pointing out that though there is a theoretical difference in the output of a DOHC and a pushrod engine, pragmatically, on the street or on the track, one engine does not ABSOLUTELY overpower the other.

I like the idea of squeezing the maximum power out of a particular engine, and I DO like the BMW V8s engine. However, when you consider practicality, the GM LSx engines are still a formidable powerplant, in spite of their low specific output.

No. They are not. Regardless of what you do, the DOHC engine will always win in race trim. You simply cannot get the same power (or revability) from a pushrod engine. Why do you think F1 cars use dual overhead cams? Do you really think they could make 800 horsepower out of a 3L with only 2 valves per cylinder? Nope, not a chance. For one thing, you could never move that much air and not float the valves. For another, the valvetrain in an OHV engine could never hope to rev that high.

Yes, the valvetrain will never be able to keep up in a OHV design. Not with 2 valves, not at 18000+ rpm. However, you need not consider such lofty racing series, because no one runs that on the street. Consider when Carroll Shelby was racing in Europe, the vaunted Ford GT40 was not powered by some supercharged BS, it was powered by a cast iron blocked pushrod V8.

[Insanity]

Yes, Vanos does improve the powerband, making the torque curve very linear. However, LSx engines, depending upon setup, are very flat in terms of torque output as well. The exceptions will always be the engines with highly hopped up cams.

The newer ones are actually pretty peaky (relative to themselves, of course). Small blocks in general tend to be peaky as opposed to big blocks. Bad thing? Not really. I was just pointing out that it's a major factor as to why the newer corvettes get such good milage for the engine size/power level.

The LS7 head flows 25% more than the LS2 head. The LS7 head has titanium valves, which helps it rev higher (7000 rpm redline) than the LS2.

"flowing more" doesn't really mean all that much. I mean, I'm sure they went to bigger valves and bigger ports, but that's only because they upped the displacement by a whopping liter. If you do the same thing to a LS2, you're probably going to lose power, since the engine can't utilize the flow capacity and you're going to tank your intake port velocity.

I like the idea of squeezing the maximum power out of a particular engine, and I DO like the BMW V8s engine. However, when you consider practicality, the GM LSx engines are still a formidable powerplant, in spite of their low specific output.

Yeah, they're not bad engines, I'm just saying if you're shooting for some crazy power level (I'm assuming that's your goal if you're shoehorning a V8 into an E30, anyway), then you're really better off with the DOHC one. The small block will likely get you to lower levels (well, 300-400hp "low") of power cheaper, but the DOHC is going to win out in absolute power if that's what you're going for.

the vaunted Ford GT40 was not powered by some supercharged BS, it was powered by a cast iron blocked pushrod V8.

True, BUT ferrari's engines weren't anything real hot in the 60s either. There's a reason why the GT40 doesn't have a pushrod V8 anymore.

[The Kasten]

Insanity,

I was reading through this thread and felt compelled to register and reply due to the amount of mis-information you have given.

With regards to the LS7, this engine is INCREDIBLE. Dyno's 450 rwhp in stock form, a tune and headers only put it right at 500 rwhp and a cam running on the STOCK TUNE put it to 548 rwhp, completely streetable and driveable. 2000$ in mods, 650+ NA hp. The things only been out for 4 or 5 months. You will see these things at 600 rwhp NA on STOCK HEADS in no time. Theyre also making over 500 rwtq too. Thats where the displacement shines. With that tq, you can gear it low on the highway and still net your 25 mpg.


About your "monster" displacement, the LSx (or SBC) are still phsyically smaller than the BMW counterpart, a very misleading stat. Ford's 4.6 DOHC dwarfs the LS1 in size but techinaclly the LS1 is 1.1 liter bigger. Externally the LSx goes from 4.8-7.0 liters, while keeping the same block, so whats the problem in maximizing displacement? it makes fine engineering sense.


About your OHV vs OHC stat, the F1 cars dont even use the traditional OHC setup, they have pneumatic valves. And dont give me that big engines cant spin. Big blocks turn 9000 in NHRA, small blocks turn 9600 in NASCAR. This is yet another misleading stat---piston velocity is what matters. NHRA piston velociites are actually higher than the F1 velocities...

And yes, the LS1 is underrated. There are plenty (100s) of instances where the cars rated at 310 crank hp (LS1 non ram air 01 up camaro/firebirds) DYNO 320+ to the wheels....now unless the driveline is EXTRA efficient, that comes to be a underrating to me.


The ZR1 big HP motors all go for 415 ci strokers....

I will give you that a DOHC head with assumingly equal valve sizing and flow #s will in the end be better because of the port velocities. But the 2v engine really has been maximized here and is going beyond what all everyone ever imagined from the SBC. for this reason, they havent HAD to revamp it.


Oh and if you want crazy #'s hp wise here are some personal friends in KY of mine

-408 ci, fully built, 522 rwhp, 505 rwtq
-414 ci, slightly less built, better heads, 530 rwhp, 514 tq
-346 ci, heads cam, stock bottom end 425 rwhp, 407 tq
- same car, a shot, 572 rwhp, 546 rwtq
-346 ci, STOCK engine, turb, 9 psi, 531 rwhp-600 rwtq
-346 ci, forged bottom, heads, cam, vortech blower 9 psi, 545 rwhp-550 rwtq


and theres a car on LS1 tech, full out race motor, monster turbo, 22 psi, 1170 rwhp...

the power potential is there. No engine in the world offers the NA modability, size, weight, great factory heads, TUNABILITY ease, efficicency, price and availability like the LS1.

:up:

[Habla]

These are cleaner, in my opinion:

Ugly exterior, but nice swap: http://www.pbase.com/yelferrari/e30_v8

Nice all-around: http://www.akgmotorsport.com/e30v8.html

[FredK]

Yeah, they're not bad engines, I'm just saying if you're shooting for some crazy power level (I'm assuming that's your goal if you're shoehorning a V8 into an E30, anyway), then you're really better off with the DOHC one. The small block will likely get you to lower levels (well, 300-400hp "low") of power cheaper, but the DOHC is going to win out in absolute power if that's what you're going for.

Yes, if you're talking equal displacement, the DOHC is going to win out.

The largest BMW V8 I've heard of is 5.2L. This is with a custom crank which probably costs more than my car. With a GM Gen III block you can get at maximum 7.4L using a custom machined 4.155" crank. This crank also probably costs more than my car.

You just can't ignore the practicalities of the engines. The BMW blocks can only fit up to a certain bore and stroke, and this all results in a smaller displacement than SBCs.

The DOHC LT5s with big output also had big displacement. Most likely these were the 415 ci engines, which translates to around 6.9L. That's a pretty high specific output though--around 116 hp/L. Not gonna be very streetable, eh? ;)

Also, the BMW V8s (even the S62) have hydraulic lifters, so the valvetrain, unless it's converted to solid lifters, will suffer from valve float as well.

[Insanity]

You know, I had a big ol' reply going to show how most of your post was flaming idiocy and sounded like a sales pitch from GM, but it basically boils down to this:

408 ci, fully built, 522 rwhp, 505 rwtq
-414 ci, slightly less built, better heads, 530 rwhp, 514 tq
-346 ci, heads cam, stock bottom end 425 rwhp, 407 tq
- same car, a shot, 572 rwhp, 546 rwtq
-346 ci, STOCK engine, turb, 9 psi, 531 rwhp-600 rwtq
-346 ci, forged bottom, heads, cam, vortech blower 9 psi, 545 rwhp-550 rwtq

Go look up some ZR1s. DOHC and modded ones completely waste those, even the FI ones.