2.8,3.1,3.4 swap questions

[stangslayer]

ive done some searching, but cannot find the answers to my question. I have heard that you cannot put the aluminum cylinder heads from a front wheel drive 2.8,3.1,3.4l motor on a rear wheel drive set up. Can any one please tell me exactly why. Does it interfere with the bell housing or what.

After much consideration i have decided that the 60degree v6 is the way to go due to its light weight. I want to use the 3.4l dual overhead cam motor if i can find one (keep in mind i will be modifying the wheel wells and floor boards). i have a m90 supercharger off a 3.8l buick v6 that will be topping off the engine with a custom intake and air to water intercooler. i will be using a t5 from a camaro with the s10 tail housing.

with all this being said, does anyone foresee any other problems i might run into other than structural integrity of the body.
thanks in advance

[Nathan Acree]

You can't use aluminum heads from a FWD motor on a RWD block because the pistons are different. I can't remember which way the compression ratio is altered but it moves drastically- Either way to high or way to low but I can't remember offhand which way.

The intakes are also different between the two types of heads as well.

But FWIW the 3.4TDC (dual overhead cam engine) is very wide, much wider than the pushrod motors. Not saying it can't be done, but there will be issues.

Hope that helps some.

Nathan Acree
Albuquerque New Mexico

[stangslayer]

ok so if the only issue is compression, that's not a big deal. there has got to be some pistons out there even for something else that can be manipulated into this motor.
does anybody know if there is any bolt up issues between the block and heads that will set me back? also intake manifolds are no big deal since i have access to machine shops and i know people who can build me a custom sheet metal intake.

[opelbits]

You might think about the 93-95ish Camaro/Firebird V6. I think it may be a 3.4 DOHC 60 degree V6.

Also, do a search on the 2.8/3.1 and performance. There is a shop here in western Missouri that specializes in the 2.8/3.1/3.4. He has a web site.

[booeman]

here's a good site for all your question's-- http://www.s10forum.com/forum/60v6-forum-2-8-3-4/

[namba209]

I guess I should jump in here, due to the fact I've got a 3.4L V-6 in my GT. To answer your question on the aluminum heads, they won't fit on a RWD engine, the block is different. Nathan is correct, the DOHC engine is a lot wider than the standard engine, and to install one you'll be doing a whole lot of sheetmetal work. As far as performance, the stock engine suits me just fine, with 140 HP at the rear wheels and 170 lbs of torque across the rpm band. You may as well know, the weak link in the GT drivetrain is the torque tube and drive shaft inside it where it slides inside the differential. Banzai starts with this setup will take out the driveshaft splines post haste. With the ZF posi I have in my GT, the recommendations are, I should be good for up to 175-200 HP, but I don't need it. To give you and idea of what it takes to install a 60 degree V-6 in a GT, read the Phases I've got in the "Articles and Projects" forum. It covers everything I did during my installation, including some of the pitfalls I encountered.

[oldopelguy]

The DOHC motor is almost the same size as a v-8, quite a bit bigger than even a 4.3 V-6. The intake manifold has the throttle body on the wrong end too, so it's going to require a ton of cutting to make fit in a GT. The only applications that used that motor were FWD, the Camaro went to the 3800 instead.

Why would you want to swap the heads from a FWD motor to a RWD one, anyway, instead of using the whole FWD motor? It's not like the lack of motor mounts is going to make a difference to you, you'll be making your own anyway. The only other real major differences are the starter on the FWD motors being on the driver's side and the timing cover/water pump assembly being all one unit on the FWD engine vice 2 different parts. The starter on the driver's side isn't a big deal, as long as you get one of the tiny ones from th late-model motors, and the FWD timing cover assembly and belts and such knock almost 6" off the front of the motor over the RWD stuff. In fact, If the weight doesn't concern you a lot you could probably slide a FWD 3.1 or 3.4 far enough forward so that the belts are almost touching the radiator and I'd bet the Camaro shifter would even be pretty close to coming out the hole. That configuration would require a lot less cutting too.

If you have the supercharger from a Buick 3800 you would be just as well off using that whole motor instead of trying to adapt it to something else. It will use the same 60-degree transmission. It's probably a bit on the big side too. Though if you do decide to use it you might want to consider using it with the RWD heads on a FWD block, the compression ratio would be low enough to not blow up under boost.

[blancojp]

If you have not purchased an engine yet, I would install a 2.8L stroker which yields a 3.4L displacement and 175HP. All for the bargain price of $1900 for the long block.

The 3800 super charger is slightly longer than the 60 degree unit. If you search the forums you will find a picture of a 60 degree engine we assembled several years ago. We spent over 10K building the engine and the result was a max of 220HP. A twin turbo would be a more viable solution which you can make easily over 250HP, having only 7.5:1 compression.

I have a 3.8L 90 degree V-6 in my car and it is easy to install as well. Just requires you to use a TH350 instead of a manual transmision and plan everything twice. But make sure you understand that if you go high in HP and use a manual transmision, you will sometimes lose control and a few other parts in the process under heavy acceleration.

So before you start cutting your vehicle, please plan accordingly with the equipment chosen.

[blancojp]

I found the link with a picture of the engine we built.

http://www.opelgt.com/forums/opel-en...ercharger.html

Enjoy!

[chazzy69]

I have a 92 firebird with a tired 3.1 and a 5 speed. Will a fwd 3.4 work with my bellhousing? One thought I had was putting a 4.3 in it. I know with 4.3 i will have change my tranny to a small block tranny. Will a 4.3 bolt in without replacing or cutting current motor mounts? You can send a reply to chazzy69@gmail.com All this seems kind of odd. What has to change to just cram a small block in it? I know the tranny would be one. would a Chev 350 bolt right in it?

[n81641]

I have used an Opel bell housing on the small GM "A" shaped bell housing pattern several times. I'm sure many would disagree with this method, but I made an Opel input shaft into a centering jig, and drilled new guide pins and bolt holes in the engine. (engine on the bench, front down) I had to make a bracket for the upper 2 bolt holes, but it worked well each time, and I have 30k miles on a 3.1 Manta, and 0 issues with the clutch/transmission/bell housing. The part that is the most questionable is the notch I cut for the starter, in the bell housing. For this I made strengthening plates, and in one case bolted them in place, and another had them tig welded. Note: this is the hard way to do things... I don't do this kind of thing any more, if it's not a bolt in kit, forget it, I have a wife, kid, house, dog, etc now, and no time. --Karl

[OpelNewb]

I wouldn't mind at some point trying to install the 4.3 into my GT but whats the best thing to source the parts from. I was thinking GMC or Chevy S10 or Jimmy or S15 truck or the Blazer. I was wondering how it would all clear the hood? I can see the biggest issue there since I would like to keep the appearing stock.

I have built up a 4.3 before with excellent results. It was a tire frying machine even in a El Camino. I really can't imagine how crazy it could be in the GT.

Also I am thinking it would be in my best interest to buy the whole vehicle and use as many of the parts from it. Has anyone ever used the rear axle from one with a coil over/four link setup? I realize it would have to be narrowed. Would the pumkin part actually clear things under the car? As well as the trans more than likely being a seriously tight fit!

I have lots of questions and I am open to opinions and advice. Thanks!

[baz]

you will need to read namba 209's thread "willit"

all will be revealed

good luck its a very long thread

[OpelNewb]

Thanks I will search it.

[namba209]

Thanx for the plug Baz. Now let's get to the real question. My engine is a 60 degree narrow block 3.4 V-6. The 4.3 is the 90 degree block which is much wider and will require more sheet metal to be removed for it to fit. JB (blancojp) has done this and other swaps and can give you some good advice on what needs to be done. IIRC he has a daily driver with one in it. I must remind everyone contemplating a swap, is, the driveline is the weak link and must be considered very carefully and fully thought out. For more of the fun and games I had during my engine tranny swap, go to the "forum jump" on the tool bar, then click on 'Performance Articles" and check out the 7 Phases I took to make the swap. HTH.

[blancojp]

As with any swap you do, there is a fair amount of research that needs to be done so you will get to actually drive the vehicle when completed. Since I am now "Retired", I got an idea about a swap which maybe a kit can be made for others to use. The aluminum engine is 140Hp in stock form, it mates to the Opel bellhousing and the ECU wiring is quite simple in comparison. I also made a new direct fire ignition system that mounts on the Opel distributor and uses 4 GM style coils. I have been a little busy with all the custom mods on Stealth but I will start posting again pretty soon.

If you don't have the tools, resources and time to do a major swap, please don't get involved. Upgrade what you have as much as possible and you will see better results. But if it was me doing the work, I would get a 2.8L stroker crate engine with a T-5 tranny. This setup I use all of the time on Mg's and believe me, a few V-8s will have a hell of a time trying to pass you.

The S-10 rear end can be fitted to the Opel quite easily by just transfering all of the Opel brackets and use a Camaro ladder torque tube. The std S-10 rear with drums is 48" wide, while the disk unit is 54" wide. The posi unit (coded G-06) is way too wide and bulky to be used efficiently.

Just remember that what you cut inside the engine bay has to somewhat be rebuilt or redone.

[shapeshaver]

Regarding 3.4 performance. Includes information on swapping aluminum Heads and FI system to th3 3.5 rwd (Camaro) block.

Some insight into the 3.4L OHV Motor... - LS1 Performance Information

Here is a quote of what was said

"All this said, it seems to be that the 3.4L engine is a stout powerplant with untapped potential. I proved this when I bolted the aluminum heads to the block itself. Using a stock 3.4L RWD engine block I mated the Gen III aluminum heads and 3100 intake (1996 model year) along with the fuel rails and larger injectors, the stock 3400 throttle body (50mm, just like the RWD stock tb) and adding RKSport headers (due to the fact that nothing else fit that would work in the RWD engine bay, pacesetter headers would work just as well) I realized a gain in the form of 27RWHP and 30RWTQ. (thats from 140rwhp -> 167rwhp and 183rwtq -> 203 rwtq). Once I took the cutout plate off to open the exhaust fully, it gave me another 3 horsepower and 3 torque (both rearwheel) taking me to 170RWHP and 207RWTQ. That’s a 30 RWHP gain and 24 RWTQ gain. Factor in 15% drivetrain loss and that comes to 200 horsepower at the engine. Now when I started, stock engine save for the 3” catback exhaust and K&N FIPK – I had dynoed at 140RWHP and 183RWTQ – that’s 164 HP and 215 TQ at the crank. Just updating the heads and intake from the restrictive version that GM put on there in 1993-1995 to the ones they were currently using in 1996 gave me an increase of 36 hp and 30 tq (170rw=>200c / 207rw=>245c) over what came from the factory. Then I decided to upgrade to the “3400” parts. I made sure I got a set of heads used on the 1999+ Grand Am GT, which featured bigger valves and roller rocker arms built in, as well as larger runners and ports on the plenum as well as an increased plenum size."


There is a lot of good info there for all interested in 3.4L OHV engine swaps.

Hope that helps.

[OpelNewb]

Thanks for the info Blancojp. I may try to get a complete Camaro or S-10 Blazer somewhere down the line. As of yet I am not ready to tear into the car like that. I am still wondering about the power that can be made with the stock engine in N/A form. I won't go turbe I have been there and done that and I want the power start to finish and the reliability of a N/A engine. I have built a Turbo Civic and it was a pain in the A@@. Lot to fit in a small package and retain the stock features. I currently drive a 08 Subaru STi and albeit the lag is not bad in it. The AWD is amazing but I wanna waste some tires if you catch my "drift"

[smittro]

Originally Posted by Nathan Acree You can't use aluminum heads from a FWD motor on a RWD block because the pistons are different. I can't remember which way the compression ratio is altered but it moves drastically- Either way to high or way to low but I can't remember offhand which way. The intakes are also different between the two types of heads as well. But FWIW the 3.4TDC (dual overhead cam engine) is very wide, much wider than the pushrod motors. Not saying it can't be done, but there will be issues. Hope that helps some. Nathan Acree Albuquerque New Mexico

No. The 3.4l dual twin cam is not very wide nor is the intake manifold. I have a custom n/a tuned 92 z34. It's a very different setup yes however it's still a 60 degree v6. The intake manifold is very small and the engine is not wider hence the 60 degree v6 title. Also yes you can use 60* fwd heads on 60* rwd engines the difference is push rods and pistons can be changed around depending on the cross over you are attempting. For more info on this you need to visit LS1.com there an article there where the guy did just that.

I also include the history of the 3.4L dual twin cam engine for the real facts about that particular engine and it's true lineage. Sorry not tryin to start a war but you don't know what your talking about.

[Nathan Acree]

Originally Posted by smittro No. The 3.4l dual twin cam is not very wide nor is the intake manifold. I have a custom n/a tuned 92 z34. It's a very different setup yes however it's still a 60 degree v6. The intake manifold is very small and the engine is not wider hence the 60 degree v6 title. Also yes you can use 60* fwd heads on 60* rwd engines the difference is push rods and pistons can be changed around depending on the cross over you are attempting. For more info on this you need to visit LS1.com there an article there where the guy did just that. I also include the history of the 3.4L dual twin cam engine for the real facts about that particular engine and it's true lineage. Sorry not tryin to start a war but you don't know what your talking about.

Go get a tape measure slick. The TDC motor is VERY much wider at the heads because of the dual cams, 60 degree V not withstanding. The width of the motor at the heads is what causes the motor to be a difficult swap into an Opel GT which is what this subject was about. I have installed a RWD F-Body 3.4 into an Opel GT and the intake on that motor BARELY fits, and the TDC intake is bigger and offset to one side. That would mean a lot of cutting into the wiper cowl. Add the fact that the exhaust on the RWD 3.4 using Fiero-style log manifolds already requires fairly extensive cutting of the drivers side footwell and one can easily see that the TDC with the wider heads would require even more to get the exhaust fitted.

I did say that the pistons are different between FWD and RWD blocks. There is that to consider as well as intake, pushrods and some other items as well like alternator brackets etc.

Basically what I was saying is that they are not a bolt on deal. I think everyone understood that but you. But hey, when you get any type of motor swapped into an Opel GT then you can come talk to me.

Nathan
Albuquerque New Mexico

[opelwasp]

Originally Posted by smittro No. The 3.4l dual twin cam is not very wide nor is the intake manifold. I have a custom n/a tuned 92 z34. It's a very different setup yes however it's still a 60 degree v6. The intake manifold is very small and the engine is not wider hence the 60 degree v6 title. Also yes you can use 60* fwd heads on 60* rwd engines the difference is push rods and pistons can be changed around depending on the cross over you are attempting. For more info on this you need to visit LS1.com there an article there where the guy did just that. I also include the history of the 3.4L dual twin cam engine for the real facts about that particular engine and it's true lineage. Sorry not tryin to start a war but you don't know what your talking about.

Wow, that's pretty bold for your first post. How many Opel GT's do you own? And for how many years have you been working on them? We have members here who have owned and worked on Opels longer than I've been alive, 33 years. You might want to check yourself befor you start talking out your a$$.

[BQS4]

Ooops, gonna have to lock this one down till the smoke clears....