Electric Porsche conversion. allegedly 0-60 in 4.8

From page 1, why are Rover V8 engines junk ? If they are treated right, they last .well. Dont rev hard until fully warmed up- (this is good practice for any engine)-keep oil level topped up,change coolant every couple of years. In the UK most of these engines run 200,000 miles. There were 750,000 215 cu in versions alone sold in the US in Buick and Olds prior to the design being bought by Rover and then refined. Good enough for Marcos, TVR, Morgan,etc to use back in the day, and the basis of the Repco Formula 1 engine. Tuning parts cost more than for Chevvies though and it is now a very old design.

1) The dropping cylinder sleeve issue.

2) Poor cylinder head design leading to wide-spread premature head gasket failures.

In drop-in trim straight from the truck it is a lowly performer. Low on hp and revs. You can modify any engine out there to make power so we're only concerned with a) how solid is the foundation we're starting from and b) how cheaply can reliable performance increases be extracted from that foundation. Because the engine has inherent design flaws (especially the aluminum 4L v8) it logically puts '(b)' into an unreasonable realm in this situation by my own opinion.

Please do not let my opinion dissuade you if by chance you find yourself up to your eyeballs in rover plants and Porsches in need of new engines. I would not seek the rover engine out based upon my knowledge of the design, my ownership experience and strong feedback from a best friend who worked at a rover dealer as a technician for 13yrs during the time these engines were in their prime. "Very common head gasket failure and yes the sleeves drop quite often on the early engines as well." For me, that's enough to say "no thank you - will try someplace else."

To each their own...

If building up a Rover V8 for a transplant, easy to fit the block with top hat liners, which alliviate the dropped liner. Cylinder head studding will eliminate the head gasket problem, and along with a good copper head gasket, allow you to turbo the engine. Heads are ok, port work is fairly easy and these engines really wake up with a better cam.

Rover did have a bad lot of early 4.0 liter engines, core shift from the foundry, but if you avoid those, you can build a nice 4.6 L V8 that will bring in a good bit of power, esp if you turbo it or supercharge it.

3.9 engines stock are almost bulletproof, I had one in a 94 Disco that went 315K miles without going into it. Still running when the truck was t-boned and totalled.

TBS, I don't know if I'd put one in a 924/944. I'd rather go with an Audi turbo or some such mill.

Has anyone tried a 2.8 out or a 90's quattro? I ask because my 91 would haul ass even with bad valve seals and 270k assuming you drop the idea of all wheel drive of course. Bell housing issues? Also not to burs to preverbal bubble but wiring and computers seem to be the worst part of any swap to those of you who have any tips or tricks? Did you replace the entire set up or just add new CPU and wiring to run the replacement abd keep stock lighting harness and fuse panel. Do not shun for soundin like a newb I know what I am lol

The 944 ecu is on a separate loom from the chassis lighting on my '84.

At a quick glance the tach will need to be wired as there is a pigtail under the dash that I believe unplugs between the ecu loom and the gauge.

Haven't dug into the remaining gauges and lamps but I've done it before on VW/Audi swaps and they're generally easy to figure out although sometimes a little time consuming to draw up a diagram and splice/flux together.

Nissan GTR inline six turbo. Big red "PORSCHE" on the cam cover. Looked like it belonged and the UAE DMV inspection didn't flag it. When I've had Alfa 3.0 V6 engines, I thought about that. A friend puts V8s in BMW E30s. How about turbo Buick V6? Nissan turbo 4s. Easy 300-400 hp. Oil pump and pickup could be problems with some engines. Burned out cranks/rods and oval bores are expensive fixes on the 944 engine. The most cost effective repair for timing belt failure is a used head or even the valves from a cracked head. The 944 engine with a cross drilled crank and lots of spares in my own supply would be my obvious choice.

You can probably use a Supra 2JZ-GE or GTE engine, which adds two more cylinders, or you can use an engine off of a different Porsche to retain the car's Porsche "soul". For the latter, I guess it'd be possible to use a Cayenne engine as well.

M30
 

Have a 92 BMW M30 Big Six 3.5 liter M35/Motronics 1.3 if you dare...
http://i1312.photobucket.com/albums/...ps81f42842.jpg

The best idea here is the 968 motor. My 928S has 240hp. In a lightened 944 that should be enough for anyone. There's always turbochargers and superchargers as well. I'd personally spend twice as much on a Porsche engine than rely on anything made by GM. No matter the cost, a Porsche is supposed to be expensive to build. That's the spirit of building a monster Porsche. No expense spared. If you can't afford it, or lack the technical know how, buy a Corvette.

I hate V8 swaps. It's just crass imho. It does make sense in the U.S. though. Sounds wrong in my book though. If I had to I'd stick with the Audi connection.

i agree that the 968 swap is likely the best. add a supercharger and you are easily up to over 300hp and about 300 lb/ft of very linear and drivable power, without the hassle of adapting this and that

i could have gone either way when i built my motor. i had the time and budget. i've also done a lot of engine swaps over the decades. what i could not get away from though is that the reality is that no off platform swap drives as well as the factory installed engines. the cars are designed for the engines put in them. all sorts of things start happening when you start monkeying around with that. to get it right, you have to spend a lot of time and money. i looked closely at a V8 swap, but it would have taken about $50k to do it right, and in the end i would have had a wannabe vette, with no value whatsoever, and would have lost all that made the 968 what it is.

what i have now retains all the spirit, reliability, and drivability of the 968, but just has a lot more of it.

I think most brand enthusiasts, regardless of make, see off-brand powerplant engine swaps as drawing a moustache on the Mona Lisa. I can however appreciate the skill and craftsmanship that many take when making such a transplant. Many of these people simply don't care what the pure brand enthusiasts think; they're on a different wavelength and that's okay. They opt out of the Porsche engine for many reasons... the cost to repair, relatively dismal performance output for a sports car, limited and relatively costly upgrade options of the 8v 944 engine. On top of those perceptions you consider the base design you're working with... I don't like the overly complicated balance shaft design, unreliable DME's, finicky trigger pickups and so on. If those are the nature of the beast then why not make things a little less beastly?


$50k is way, way off the mark for a GM swap. I priced this swap myself and it came in at less than $10g including the used LS engine/clip. Unless you're including the cost of erecting a new garage to complete the build in, I don't see where the other $40g goes.

i agree, and have done my fair share of off brand stuff. i've jammed V8s into pintos, mgbs, fiats, and porsches, to name a few. i've done them quick and dirty, as well as super high dollar installs. you can imagine the results. garbage in garbage out. spend the money, get something fun. no free lunch.

as for the TRUE cost of a V8 installation, you have to include the increased brakes, suspension, frame reinforcement work, strengthened torque tube, larger axes, reinforced transmission, electronics, cooling, wheels, tires, and all the other stuff required. it adds up in a hurry. if you fail to do these things, you end up with a rattly uncivilized pile of crap. been there, done that.

i've seen a lot of these V8 swaps in these cars, and so far i've only seen one that is close to being right, and he spent a ton on it, likely far more than $50k. the rest have been cobbled together messes, with no attention paid to detail (like even tidying up wiring and hoses).

as for the engine itself, i would NEVER install a used engine into anything. that's just plain stupid. if it's out, rebuild it. it's such a pain to get this kind of thing done to begin with that it would be foolish to stop short like that.

Are the majority of those costs and modifications not required for the same output when using a Porsche engine that has been warmed over though?

Power is power. You can't say 350hp from a similar weight LS requires $40k more in supporting mods than a 350hp Porsche engine.

I've heard this same BS uttered over and over again about how you need bigger brakes or better suspension components.

Brakes can be required if you're exceeding the thermal capacity of the stock brakes or if you're looking for better feedback (stiffer calipers, larger rotors). Whether you're running a 300hp 4-cylinder or a 300hp V8, the terminal velocity will be similar.

Same with the suspension. Unless you're needing to improve the transient response or increase the lateral acceleration, I don't see why an engine swap that does not negatively impact the weight balance or CoG would alter that. Most V8 swaps have not impacted the corner balance of the cars enough to require massive changes. I could see the need to make minor adjustments to the corner weights to adjust for changes in the vehicle balance, but that isn't uncommon for any cars and doesn't require large amounts of money if you know what you're doing.

Most of the work done to the chassis of the V8 swapped cars are to improve issues that are prevalent in the design of the car itself and is more or less exclusive of the power driving it. Things like bumpsteer and lack of decent camber curves on the front suspension for example. Perhaps the added torque can exacerbate some of those problems, but they are still there and we all deal with it.

Do some reseach on the current engine swap work and you'll see there are things that have been done that were required due to failures or to prevent potential failures due to known limitations and others simply because they feel they wanted to for either personal preference (read: I can do it as good or better for cheap or I want it to look a certain way) or for their particular situation.

I will agree with reinforcing some of the drivetrain components and luckily the Audi 016 transaxle is one of the popular alternative solutions for V8 powered Lamborghini and GT40 replicas, so there is information available on ways to strengthen the transaxle to compensate a little better with the power outputs provided by high boosted 951's or V8's. The V8 944 hybrid forums has information on improving the transaxle mounts, axles, etc.

I've not heard of any issues with the torque tubes themselves (aside from the occasional broken shaft due to neglect/wear) as the coupler or the axles tend to be the weak link, but then high horsepower 951's have broken those, so again it isn't directly a V8 swap issue, its an issue with components being used past their designed limits.

Sometimes I find engineers and armchair engineers get to buried in the vision of perfection to see the reality is much less difficult and reachable, especially if you take it step by step and only focus on the required changes.

if you have more power, you will drive faster. that means you need more brakes. same for suspension, tires, and wheels. if you aren't going to be driving fast, then you're probably fine. but then, what is the point of an engine swap?

i only have a bit over 300 lb/ft with my current setup, and i can feel the shaft twist and flex. i have super bearings in there and everything. any more than that, and i am quite sure i would sheer the splines.

never tried the 016 box. not sure it was out there at the time (1988). i blew up two 951 boxes though with a blown small block ford in a 944 that had about 400 ft/lb.

as for the costs, yes, much of this would be needed regardless of the power plant. increase power that much, and the car has to be made to handle it. having done a number of these kinds of things, as a shop, and added up the costs at the end, it is never as cheap as almost everybody thinks.

not saying it can't be done or that it isn't a good idea. just saying it isn't easy, and you really have to want something like that. also, no matter how well you do it, it isn't likely you will ever find anybody who thinks nearly as highly of it as you do when it comes time to sell it. a lot of this comes from a complete lack of a workshop manual for the car. it's hard for anybody to come in behind you and take care of it without one.

*flash968- You're right about the end product only being worth it to you. I see 944s listed for crazy amounts, as we all do, because of some mods the po did to it. The mods are only worth the money if you can find someone who wants the same mods. I race a few of my 944s and would have to say I'm happy with them the way they are. If I wanted to move up in class or have a much faster car, I would have to say I'd sell a few of my 944s and just buy a 911. The work is already done. Perhaps I just don't see why you would go to the time and expense to put anything else in a car other than what is there. I guess just to do it is the point. I rebuild the cars I buy back to stock (except for the track cars). Porsche never apologized for the 2.5l, as they shouldn't. It is a low cost to maintain engine and fun to drive. When I don't feel it is fast enough I'll just move on to a different car. Just my unsolicited thought.

All 944 boxes are audi 016 based boxes.

Having an S and a 968 swapped s2... The 968 motor is much better down low, it launches so much better than the S that I have problems when I step back into my S until I remember I have to give it more off the line not to chug.

the 968 swap is awesome, I would recommend it. That said, I've been thinking about a high revving 4.8L LSx lately. 350/350 with 7000+ rpm sounds fun and fits the spirit of the car. The "lack" of low end grunt on the 4.8 vs the 6.0 LSx's should help my drivelines survival a bit.

I would have thought that peak hp really doesn't matter, it's the torque you have to stop with your brakes. Seeing as an 300hp V8 can probably produce 300lbft at 1000-2000 rpm and a 300hp 4-cylinder won't be even close to that torque at the same rpm. You have a lot more torque to stop in a V8 than a 4-cyl and that must demand bigger brakes.

Same argument for suspension upgrades, the extra low down torque in a V8 will affect the chassis much more than the same hp 4-cyl engine due to much higher torque coming into play earlier.

How much torque are you producing when you let off the throttle to brake?

C'mon...

9FF - correct.

as for a 4 cylinder and torque capabilities, if you had a roots blower, you could make that torque at 2krpm. with a centrifugal you'll only get about 220 at 2k, and won't see peak until 4k. with a turbo, you won't get diddly until over 3k, but you could get more at peak.

it took quite a bit of time and money to get my blue 968 to be able to handle the power it has now, and even now i am at the limits of the car. a bigger, heavier engine (yes, the LS engines weigh more), with more torque, would need even more.

id love to feel the torque of an NA 3.0 8v...

I would ask that you please don't encourage and reinforce thoughts that are not fully formed. How can you say this is correct: You need bigger brakes to stop a v8 because it produces more torque????

No. Absolutely incorrect. The output of the engine for HP/torque does not translate directly to brake requirements. Brake selection is better when considering the total mass you are attempting to slow (entire weight of the vehicle)and also the frequency of brake operation. Engine output is not primary in considerations.

You need brakes to match your driving style regardless of the engine swap. It's a popular modification to put smaller diameter rotor brakes on quarter mile cars so you can run a smaller wheel and thicker sidewall tires. If you are overrunning stock 944 brakes on the street then you need to slow down.

I'm aghast at the misinformation here. Absolutely ridiculous.

If only those 2.7 heads were not so expensive. It would be fun, but i think the 968 would still out torque it due to the variocam. The S2 has some really good grunt, even down low and then revs so quickly due to the heads ability to flow. Its so fun! I say this and i'm at 6000ft and loose something like 18% of my power to the altitude, if i took this car to sea level i'd be in for a treat. I know my S lost 25hp on the dyno in denver vs its altitude corrected number. It put down 152hp altitude corrected vs its real number of 128, this was at the wheels.

It was more a query than a fact I was posting, that's why I started the post with "I would have thought". We're not all physics geniuses here, it's a forum, we query things and ask questions, and don't expect to be ridiculed because we don't know everything, thanks for your input.

Not directed at you - asking questions is okay. I agree questions and answers are why we are here. When the answer is completely wrong we need to make sure the bs is nipped in the bud. That method will make us all smarter.

So to clarify the brake query, the only reason you need bigger brakes for a LT/LS conversion is because of the weight difference?

944na to LT/LS is 150-400LB more weight
951 to LT/LS is 50-200LB more weight

So you do need to upgrade brakes and probably suspension, correct?

The weight difference for an Ls swap is 50lbs.

Would you upgrade brakes and suspension for that amount? Maybe. If you were dialing in a suspension for a specific track. Necessity? No.

i dont know what it is, but every 968 ive ever driven feels slower on the low end than any S2...i dont doubt they are faster overall but for going around town...id take an S2 any day.

S2 engine swaps have built some successful 944 race cars. I know that to be true.

Always thought these engines started with Buick?

More tq might just be a number on a page but I believe what he's saying is that if you have it at your feet, you'll use it more readily. So if you have the low down tq of an n/a V8 you might be prone to be travelling faster at the next stop light (wherever) than if you had to reach your peak (and lesser) tq at 5000 rpm. You may not be so inclined to rev the rings out of the motor to make it reach 100 mph with a smaller n/a motor. Just hypothesising here. Nobody is saying you need bigger brakes to slow down the same mass..but if the mass is travelling faster then perhaps you might. Same as adding stickier tyres. How would this necessitate bigger brakes? You go around the corners faster therefore reach your next corner at a higher speed. You brake at a certain point to pull you up in time to make the next corner or come to a complete halt. The brakes don't care about what motor you have up front, but they are used proportionally to the speed you're travelling at. With higher earlier tq you may just be going faster, sooner.

As for justifying a V8 swap on the basis that it produces 300bhp...puhleez...what would be the point? That would be just another ****box you see advertised on Craiglist...and I'm not even from the US. If you are going to do the swap, you want at the very least 400bhp and then, yes, you should factor in for the better suspension, brakes blah blah blah....

That's more logical and thank you for the thoughtful reply. It all comes down to how you drive which has to do with the driver not the engine under the hood. The initial implication that a v8 swap required such and such mods over the hot rod 4cyl is what we've just debunked. The weight similarities could nearly be eliminated with a battery relocation or smaller unit. The difference is so small that between drivers you might see more of a difference (driver Bob weighing in at 240lbs after a healthy breakfast, driver Tim weighing in at 160lbs after visiting the port-o-let).

I had a 1.8L 4cyl GTI in high school that I cut my teeth on that is similar mass to a 944 (~2600lbs). I could get those brakes glowing and smoking on the back roads hauling ass. I didn't need an increase in HP to require bigger brakes I only needed to drive like a maniac on public roads. It took work and recklessness to get those brakes hot.

"I have a faster car so I'm going to automatically drive faster." We're not in highschool anymore (well, maybe a few of us literally are) so hopefully we know better than to run a Porsche to the mechanical limits of the brakes on public roads. The brakes these cars come with are not 9.1" solid rotors with miniature drum brakes in the back like my similar weight GTi example above. These Porsche cars come with decent brakes relative to other makes. With these better, OEM Porsche brakes, it will take far more aggressive and prolonged driving than the canyon/gulf runs and it won't matter which engine you have if the power output and weight is similar.

Don't forget Lapkritis, the 50lbs difference is a comparison between the 951 and all the turbo accessories to the GMV8 and all accessories. There's folk out there putting the V8 in the na which is about 100-200lbs lighter than the 951 depending on the MY. iirc an LS1 in an early na adds nearly 200lbs to the cars weight. Definitely need to work the suspension and brakes in that case.

Please share your data source for the 200lbs number. I have an 8v here on the stand with balance shafts and all accessories. It's HUGE and heavy.

Have you worked with an LS before? They're also aluminum. They're light and relatively compact. They're easy to modify and perform superiorly to the 944 powerplants across the board and at a lower cost.

Even if we arrive at 200lbs difference eventually (which I doubt when comparing apples to apples)... my point remains. It's a small difference in weight. The point that the number of cylinders somehow relates to the size of brakes required is complete hogwash. Take a 500hp 4cyl swap in a 944 with LIGHTER weight than the 944 engine. Should I go both smaller brakes then? The logic doesn't work. This topic is done.

lapkritis - what i was agreeing with was 9ff's comments about the chassis.

as for brakes, if you drive faster because of more power, as EVERYONE does, you need more brakes. it is as much about speed as it is about weight. that's why 951s have bigger brakes than a regular 944, though they are nearly identical weights.

333 - thank you - that's exactly what i was getting at

re: weight difference, it's more like 100lbs when you are all said and done, using the all aluminum version. you have to take what is on the internet with a grain of salt. american engines are weighed without intake, or any accessories bolted on. german engines are weighed complete. also, the increased cooling capacity required, and added exhaust weight, and other such items, all factor in. in the end, you gain about 100lbs up front.

How about a turbo volvo 5 cylinder? I don't know anything about them other than a friend had one that was impressively quick after he did some mods to it.

The 50lb difference commonly banded about it the overall difference in car weight between a 951 with a 4cyl and a 951 with an LS1. They are comparing engine/turbo/piping/intercooler, etc to the LS1 weight with all accessories and it's about right. The na doesn't have all the turbo accessories to start with, it's a lighter car by about 100-200lbs overall depending on MY compared to the turbo.