I have been thinking about doing a 4.9 Liter swap in one of my Fieros for awhile. I have decided that I was going to build the engine up first and work on it a little at a time. I have been thinking of what I can do to the 4.9 Liter engine performance wise. I love the sound of a Ferrari and I am thinking about getting that out of a Cadillac Engine, I know I am crazy, but I think I have figured out how Ferrari makes their V8's sound like they do, the very short stroke they have (1.70 in.), thats short, but they also have a 4.33 in. rod length and a 3.6in. bore. So lets compare the Ferrari engine to the 4.9 Liter, the 4.9 liter has a 3.6 in. bore and so does the V8 Ferrari engine, the 4.9 Liter has a 3.622 in. stroke on the other hand the V8 Ferrari has a 1.70 stroke, thats a huge difference in size. The rod length of a V8 Ferrari is 4.33 in. compared to the 5.709 in. the 4.9 Liter has. My plan is the get a custom crankshaft made up for the 4.9 Liter that has the 1.70 stroke and use the stock size rods. This and a good exhaust would get you that Ferrari growl. The only thing that is different and will probably make a difference in sound is the 4.9 Liter is a 2 Overhead Valve system, the Ferrari V8 is a Dual Overhead Cam, so it has 4 Valves per cylinder. So the other option would be to use a Northstar engine and shorten the stroke on it like I am thinking about doing on the 4.9 Liter.

All opinions are encouraged. Basically I am wondering if this would actually run or would I have to do other mods to get it to run or would it run at all, like another cam profile. I think this engine would be crazy sounding and could turn some serious RPM's, if I could make it work. Please do not flame me for this, this is just a thought of mine that I am curious about and would like to see happen.

Make a flat plane crank, or some 180* headers, then ya, it would sound like a ferrari

O and a 180* crank will let the engine rev faster

[This message has been edited by RideZiLightning (edited 02-15-2008).]

quote Originally posted by craigsfiero2007: So lets compare the Ferrari engine to the 4.9 Liter, the 4.9 liter has a 3.6 in. bore and so does the V8 Ferrari engine, the 4.9 Liter has a 3.622 in. stroke on the other hand the V8 Ferrari has a 1.70 stroke, thats a huge difference in size....My plan is the get a custom crankshaft made up for the 4.9 Liter that has the 1.70 stroke.....

If your bore and stroke numbers are correct, just be aware that using a stroke that much smaller will reduce your engine's displacement by more than 50%. Your 4.9L Caddy engine will become a 2.3L Caddy engine.

If you want a Ferrari sound, start with a 3.4 DOHC. A V8 with a 180° crank doesn't sound a whole lot different than the V6. Listen to one before you make up your mind on which engine. The 3.4 DOHC will have about the same HP as a stock 4.9, but less torque. The bonus is it loves to rev, which also fits the Ferrari feel. Even with the Ferrari sound, a 4.9 will have to struggle to hit 5000 rpm, unless your mods extend that range. The 3.4 DOHC can turn close to 7000 rpm bone stock.

Now's my chance to plug the 1990 Caddy 4.5 which is a shorter stroke longer rod version of the 4.9l. 1990 is the only year with the long rod. Think 327 chevy compared to a 350. Should rev much better. Uses the same heads should breath better than a 4.9 due to samller displacement and longer rods breath better...

quote Originally posted by Formula88: If you want a Ferrari sound, start with a 3.4 DOHC. A V8 with a 180° crank doesn't sound a whole lot different than the V6. Listen to one before you make up your mind on which engine. The 3.4 DOHC will have about the same HP as a stock 4.9, but less torque. The bonus is it loves to rev, which also fits the Ferrari feel. Even with the Ferrari sound, a 4.9 will have to struggle to hit 5000 rpm, unless your mods extend that range. The 3.4 DOHC can turn close to 7000 rpm bone stock.

The f430 has a flat crank v8

quote Originally posted by RideZiLightning: The f430 has a flat crank v8

I know. That's why I pointed out that it sounds similar to a 60° V6.
The firing order is different on a flat crank V8 vs a conventional 90° V8. No matter what you do, it's going to sound different. The V6 has more even exhaust pulses - like the flat crank V8.

Make a recording of a Ferrari, put a big sub woofer in you car, and play the recording

quote Originally posted by craigsfiero2007: I have been thinking about doing a 4.9 Liter swap in one of my Fieros for awhile. I have decided that I was going to build the engine up first and work on it a little at a time. I have been thinking of what I can do to the 4.9 Liter engine performance wise. I love the sound of a Ferrari and I am thinking about getting that out of a Cadillac Engine, I know I am crazy, but I think I have figured out how Ferrari makes their V8's sound like they do, the very short stroke they have (1.70 in.), thats short, but they also have a 4.33 in. rod length and a 3.6in. bore. So lets compare the Ferrari engine to the 4.9 Liter, the 4.9 liter has a 3.6 in. bore and so does the V8 Ferrari engine, the 4.9 Liter has a 3.622 in. stroke on the other hand the V8 Ferrari has a 1.70 stroke, thats a huge difference in size. The rod length of a V8 Ferrari is 4.33 in. compared to the 5.709 in. the 4.9 Liter has. My plan is the get a custom crankshaft made up for the 4.9 Liter that has the 1.70 stroke and use the stock size rods. This and a good exhaust would get you that Ferrari growl. The only thing that is different and will probably make a difference in sound is the 4.9 Liter is a 2 Overhead Valve system, the Ferrari V8 is a Dual Overhead Cam, so it has 4 Valves per cylinder. So the other option would be to use a Northstar engine and shorten the stroke on it like I am thinking about doing on the 4.9 Liter. All opinions are encouraged. Basically I am wondering if this would actually run or would I have to do other mods to get it to run or would it run at all, like another cam profile. I think this engine would be crazy sounding and could turn some serious RPM's, if I could make it work. Please do not flame me for this, this is just a thought of mine that I am curious about and would like to see happen.

You will have to deck/cut 2" off the top of the block to get a usable compression with the shorter crank. Then match up all the top end parts to bolt back on. That would make the intake about 2" to wide to bolt on. It just wont work. But to have a custom made crank like that could cost $3,000 and who knows what a full custom cam will cost?. Just start with a North Star and put your money in it with the stock length crank and rods. Have a flat crank and cam set made (if they are not made already) and tune it.

That being said, IF all you want is "the sound" get a 3.5 Nissan 350Z LQ5 and swap it in your car. Use the Nissan Maxima 6 speed tranny. This engine sounds AMAZING even in the Infinity. VERRY "Ferrari" like and VERRY popular for the after market.

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Fancy timing curves can make for a different sound right?

Cam timing, lobe separation, head porting, exhaust feningleing, all should make sound improvements.

The bore and stroke of the 4.9 are both 94mm or 3.7 inches according to Wikipedia.
I don't believe this has much to do with the sound though.
I agree with the above posts that it is the flat crank that is the key. However, the benifit of the flat crank is better exhaust breathing, but if you have equal length exhaust runners on each cylinder bank and both banks overall.
This results in all of the exhaust pulses being evenly spaced at the end of the pipe and that gives you better breathing as the inertia of the gas pulses is best maintained and that gives you more power and the resulting music is an inadvertant delight.
I have considered this option too. In addition to the cost of the crankshaft, you'd need a custom made cam to accomodate the new firing order. The electronics should be fine once you switch the sparkplug wires to the appropriate distributor outputs.
One last note, I met a guy the other day with an LS1 in his GT (at AutoZone of course) and when he cranked it up, it didn’t sound any different from my stock GT. He told me that it was the stock exhaust system so there you go. So don’t be surprised if after all of your efforts, the sound is little changed. Hell, it sounds great anyway to my ear.
My GT reminds me of my old Healey 3000 with side pipes. It looked fast and sounded fast. Too bad it wasn’t fast. “Two out of three ain’t bad.”

quote Originally posted by Rickady88GT: You will have to deck/cut 2" off the top of the block to get a usable compression with the shorter crank. Then match up all the top end parts to bolt back on. That would make the intake about 2" to wide to bolt on. It just wont work. But to have a custom made crank like that could cost $3,000 and who knows what a full custom cam will cost?. Just start with a North Star and put your money in it with the stock length crank and rods. Have a flat crank and cam set made (if they are not made already) and tune it. That being said, IF all you want is "the sound" get a 3.5 Nissan 350Z LQ5 and swap it in your car. Use the Nissan Maxima 6 speed tranny. This engine sounds AMAZING even in the Infinity. VERRY "Ferrari" like and VERRY popular for the after market.

I thought about using the Northstar Engine and putting a flat crank and cam in it. The Northstar has Dual Overhead cams like a Ferrari or any other exotic car. I did my math and the Northstar has a 3.6 in bore and a 3.31 stroke and 5.945 rod length with a 9.0.1 compression ratio. If I destroked it to 1.70 in. then the displacement would be 2.2 Liters 138 CI, just like the 1989 Lotus Esprit Turbo SE, minus the turbo. What would be a good stroke for the Northstar Engine?

I thought about the 350Z engine too, but I would be lucky to get my hands on one for a decent price. But they do sound pretty close to a Ferrari.

I don't understand the destroking? What exactly do you want to do it for? If you had a flat crank N* you would have a true Ferrari sound and GM reliability, If it were done right. No need to destroke. Instant RPM can be had with a lighter flywheel.

Is there a particular 2 liter Ferrari v8 you're wanting to impersonate? Ferrari hasn't made a v8 displacing less than 3 liters since the 80's.

If you want to sound like a modern Ferrari, you're best off having a flat-plane crank made for the Northstar (standard stroke or 3-4 mm less to make it displace as much as a 430), have a nice pair of similar-length headers made, and get your hands of a 430 muffler. Then change the rest of the engine to make power and hold together up to 9000 RPM.

[This message has been edited by Fiero Brick (edited 02-15-2008).]

I just like the Ferrari sound or any other exotic car sound. Flat-plane Crankshafts, tell me more about this please. Has anyone done this with the Northstar?

quote Originally posted by craigsfiero2007: I thought about using the Northstar Engine and putting a flat crank and cam in it. The Northstar has Dual Overhead cams like a Ferrari or any other exotic car. I did my math and the Northstar has a 3.6 in bore and a 3.31 stroke and 5.945 rod length with a 9.0.1 compression ratio. If I destroked it to 1.70 in. then the displacement would be 2.2 Liters 138 CI, just like the 1989 Lotus Esprit Turbo SE, minus the turbo. What would be a good stroke for the Northstar Engine? I thought about the 350Z engine too, but I would be lucky to get my hands on one for a decent price. But they do sound pretty close to a Ferrari.

The northstar has 10.25:1 compression ratio stock not 9.0:1. Buying a 350Z or G35 engine would probably be cheaper than making a custom crank and everything to go with it. If you want the ferrari sound I think you should buy a ferrari engine. There was a video clip floating around here a while ago of a fiero with a BMW 4.0L V8 and it was definatly the closest "ferrari like" sound i've heard in a fiero.

EDIT: heres the link to the videos of the BMW engine
https://www.fiero.nl/forum/Forum1/HTML/068865.html

[This message has been edited by Zac88GT (edited 02-15-2008).]

All other things being equal, with the shorter throw of a custom, destroked crank, each piston will travel less far up in the cylinder than it did prior to the installation of the destroked crank. In turn, without additional modifications, then the reduced upward travel of the piston within the cylinder will reduce the engine's compression ratio.

With the magnitude of the reduction in stroke you've been talking about for the Northstar engine or the 4.9L caddy engine you mentioned earlier (using a 1.70" stroke instead of a 3.31" or 3.60" stroke), the resultant engine compression ratio would be reduced to a sluggishly low level.

Accordingly, that major reduction in compression ratio needs to be reversed somehow, possibly via some combination of custom-made pistons, which are domed or have had each one's wrist pin moved further down the side of the piston (if that's even possible with the engines you've mentioned), decking the block (which Rickady88GT already mentioned), and probably longer, custom-made, connecting rods for the engine.

In turn, each of those potential remedies has its own drawbacks. For example, aside from being expensive, custom-made connecting rods that are longer --- to compensate for the shorter crank throw --- also often are rods that are heavier, which unfortunately serves to reduce their RPM potential. In turn, that heavier rod weight theoretically can be compensated for by switching to custom-made rods employing a more exotic, lightweight material like titanium, which of course makes the custom rods even more expensive. Then, despite all that, one still would only have a 2.3L V8.

Although not widely known, another alternative for your Fiero might be a 5.3L SBC. That engine would be a high-RPM screamer, something I assume you're interested in because of your interest on engines altered to create a higher bore-to-stroke ratio, which is known to favor higher-RPM operation.

A couple of people here on PFF have built one, and probably for considerably less than the 2.3L V8 we've been discussing here. Because of that 5.3L engine's 4.155" bore and 3.000" stroke which produces a bore-to-stroke ratio higher than that of more typical SBC build-ups, that 5.3L set-up enables more emphasis on higher RPM operation.

In fact, although I've not yet heard of anyone having installed a 5.3L SBC engine in a Fiero, I expect it would make for one f-u-n, high-RPM screamer of a ride.

I have done some research on the Flat-plane crankshafts, if I do get a flat-plane crankshaft made that still has the same stroke as the original stock one, I will have to get new camshafts and switch all the rods to Titanium rods and light weight pistons. So I probably won't destroke the engine. I read that the flat-plane crankshafts in any V8 will give it that exotic V8 car sound I am looking for and it will allow the engine to turn some serious RPM's. So now I need to figure out what I have to have for camshafts, I will more than likely have to have different cams, right? If I do what will I have to use for a cam profile? I will probably use the 4.6 Liter Northstar for an engine. I also plan on using equal length headers. Is there anyone that makes equal length headers for the Northstar?

quote Originally posted by craigsfiero2007: I have done some research on the Flat-plane crankshafts, if I do get a flat-plane crankshaft made that still has the same stroke as the original stock one, I will have to get new camshafts and switch all the rods to Titanium rods and light weight pistons. So I probably won't destroke the engine. I read that the flat-plane crankshafts in any V8 will give it that exotic V8 car sound I am looking for and it will allow the engine to turn some serious RPM's. So now I need to figure out what I have to have for camshafts, I will more than likely have to have different cams, right? If I do what will I have to use for a cam profile? I will probably use the 4.6 Liter Northstar for an engine. I also plan on using equal length headers. Is there anyone that makes equal length headers for the Northstar?

Just to keep this real, I should mention that an engine like this will cost you $12,000 or more. If you cheap out and have just a set of cams made to go with the crank it will still cost over $5,000. I don't know of a "kit" to swap a N* over to a 180* crank but if it did exist it would be VERY expensive. Porting heads would be a must for such a radical engine and that job can be over $2,000. Then there is the tuning. After all the parts are in the engine it should be dyno tuned for best results and that aint cheap.
I would never think of doing this kind of work myself with such little experience.

I am not trying to stop you but I think the magnitude of a project like this has to include a price check.

I would even swap in a stock Ford 4.6 SOHC with shorty equal length headers for a much better sound than a SBC, LSx, or N*

the easiest most cost effective way you are going to get the Ferrari sound out of a 4.9 v8 is to build 180* headers for it. Have fun with the space constraints. You will have to mate up 2 common bank cylinders 180 degree off from each other with the corresponding 2 cylinders from opposite banks with eah other into a shared collector in a transverse layout. That's why the GT40 crowd calls the headers on a longitudual mount V8 Ford ( which BTW is much easier to do than a transverse setup) a "bundle of snakes" in the GT 40. Its a scary mess that really does have form and function. "The ends justify the means" comes to mind Here is an example of that setup http://videos.streetfire.ne...7b-9958016193e9.htm. Who would not want that sound in a Fiero?

Then you will still have to deal with the low rpm characteristics of the 4.9 which means a revised valve train as in, stiffer springs, lighter lifters( solid even), lightweight roller rockers and pushrods, a more radical cam built for top end, head port work along with a less restrictive intake and possibly a shorter stroke to be able rev faster and higher.

As Formula88 mentioned, a 3.4 DOHC will come closest short of building 180* headers or a flat plane crank and customs cams ( for northstar) which would be very expensive. The 3.4 DOHC has the 120* firing pulses ( and every firing pulse on the same manifold is even due to the firing order alternating front one cylinder bank to the next) much closer to 180* Ferrari pulses than the 4.9 90* out of phase firing pulses ( because the out of phase cylinders share a common exhaust manifold collector) which give the 4.9 that classic American V8 rumbling burble sound.
Heck, even the stock Fiero 2.8 has 120* pulses even though it doesn't have the quattrovalvole heads the 3.4 DOHC has. The 3.4 DOHC actually sounds like half of a lambo V12 . As mentioned the 3.4 DOHC will rev to 7000rpm stock, very close to a street Ferrari engines top rpm which is about 8500 rpm.

A Ferrari V8 has a 90* block and 180* flat plane crank which means it's 2 4 cylinder engines joined by a common crank. There are different firing orders availible in such a configuration. Just ask the Ferrari F1 team for details

You could also just put 2 Hayabusa 4 cyl engines in back with dual exhausts or any four banger for that matter and run dual exhausts
or, get a Ferrari engine ...I have one I am planning on putting in my X19 instead of the Fiero as its a 3.0 and the X19 is MUCH ligher than a Fiero

[This message has been edited by Erik (edited 02-18-2008).]

I just wanted to add ..keep your primaries and general exhaust tube sizing small for a higher tone to help with the sound. Tuba players agree. I would use 1.5 inch primary max and no bigger than 2 in after the collector for a good compromise in flow and tone

[This message has been edited by Erik (edited 02-18-2008).]