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2.8 ---> opel

2857 Views 12 Replies 6 Participants Last post by  namba209 (R.I.P.)
I've decided on my plan for the opel's power plant. I have a 2.8 from a 84 FWD setup. I'm going to run that. I'll rebuild it with some upgrades and all, and probally run a Edlebrock manifold, with a small 4 barrel, and headers for it, probally modified a bit.... Keepin' it simple and carburated. I guess any 5spds from a camaro or s-10 with a 60deg v6 will work right? actually I think that even a v8 trans would bolt up, just the amount of splines on the input shaft is different. But a V6 trans is easier and cheaper to find.

I know there are probally threads about this, but I just want to know the basic things that need to be done to put this in a 72 opel manta. Fabricating isn't a problem, I've got a mill, welder, and anything else that would be needed. So whats the basic things that need to be done?
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read the article on the oana website, all modifications will be the same as the GT except maybe the cutting of the engine compartment, the Manta may not need to be cut because there is more room in there.
Two things you need to check on. First the transverse mounted V-6s have different bellhousing bolt holes, second, the T-5 for an S-10 will work in a GT because the shifter is centered on the tranny, other GM T-5s have the shifter on the tailshaft. I don't know if that would be a problem, but you need to check both out before starting. It may be cost prohibitive to do the machining to get what you have to work. Just my $.02.

Yep. And an S-10 has about a 3.56:1 low gear. That's 12.6:1 net ratio with the rearend. Nice tire squealer. Most RWD have hydraulic clutchs, a few use cables like an Opel. The S-10 clutch is hydraulic. V8 T-5 trannies cost twice as much as V6. Neither is very strong if you're racing.

A 390 cfm Holley carb is nice, looks good, but costs more. 600 cfm is way too much carb for 2.8L. Many racers use the stock 2 barrel intake. Yes - stock 2 barrel. They mildly port it, esp. in the plenum, and use a 500 cfm Holley 2 barrel on a homemade adapter. It's good up to about 270 HP. 2 barrel carbs are rated differently, 500 cfm = 354 cfm 4 barrel. Holley also makes a 350 cfm 2 barrel (costs more). Another option is a '75-'76 2GC Rochester. You can even buy modified versions at a decent price that'll be more than big enough for your engine, although stock is fine and available at parts stores. Of course there's lots of TBI units in salvage yards, esp. on trucks.

There's a lot of pics posted. I'd search thru them.
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Thanks for the replys. Ya I did a little looking around, and the FWD motors have the starter on the other side to I think. I think I may just look for a 2.8/5 spd complete setup from an S10. I was hoping to save a little on the motor.
I would have needed to used a different intake because of the FWD has the waterneck in the back of the intake. Edelbrock does make a good 450CFM 4 barrel carb. My buddy ran one on a chyrsler slant six 3.7l, and it worked awesome. The advantage to the 4 barrel is the staged secondaries, and the barrels are smaller which will help signal and all that stuff.
why does every one want to chop up opels? they werent 400 hp muscle cars and wont be unless you really reinforce the frame. I would suggest doing that on a full framer, something that will be easy to weld more metal onto it to reinforce it. just an idea.
Jordan, I've had this car for a long time and one before it. My reasoning for the upgrade is real simple: It took me 3 1/2 miles to run the car from a stop to an indicated 150 MPH @ 7000 RPM. I don't need to go any faster, I just want to get there quicker. I can really appreciate the folks that want to keep their cars totally stock, and there are some that want bigger Opel engines and all the bells and whistles that go along with that. I can appreciate that too. They may have reliablilty problems with modified engines, it is a common agreement that more modification, less reliability, to a point. I'm putting a fairly stock engine in MY car that will get me down the road at a reasonable rate, will look good, and if I want to smoke a rice burner that's playing "Tom Fool" on my freeway I can. So far, the only sets of wheels I have that cannot do the century mark in a mile or a lot less, is my GT and 38 foot motorhome. I like to drive "fun"

#1. To use fully 450 cfm you'll need to rev past 10 grand. My guess on a 3.7L it doesn't kick in much on the secondaries. And a liter is a lot of extra engine, even for V8's. The 450 cfm worked great on my 4.3L and the 600 cfm sucked. Crossing the line to too big is bad. Plus, 450's have limited adjustments, so adjusting for the less cubes isn't easy. An Edlebrock 500 cfm is easier to adjust. If you want staged secondaries Webers work too.

#2. 1.9L is whimpy. People love the car and want more power. I'm surprised more aren't using turbos. It'll make a 1.9 run like a 2.8 with less work and cost. As for those that use cheap donor engines, their day will come shortly when the engine needs a rebuild and it isn't cheap anymore. Power comes at a price.
2.8 primer

The engine to transmission bolt pattern is the same on both the FWD and RWD motors.

The early FWD 2.8's, the ones with cast iron heads and stamped steel valve covers are almost all the same as the RWD ones, with the exception of manifolds and timing covers. Their starter is almost always on the passenger side. All of the S-10 2.5 4-cylinder and 2.8 6-cylinder transmissions, manual and auto, have the starter pocket in the bell housing for these motors.

The second generation 2.8 and 3.1, and third gen 3.4, the FWD ones with the aluminum heads and almost flat aluminum valve covers, had the starter on the drivers side of the motor. Some of the Crapmaro 3.1's and 3.4's also had their starter on this side. Early Crapmaro 2.8 and 3.1 transmissions had starter pockets on the passenger side, like the S-10, later ones had the pocket on the drivers side. Most of the 3.1's from the early '90's actually had starter pockets on both sides, to allow either starter position.

Newer S-10's with the 2.2 ecotec motor have the same bolt patern for the motor to transmission, but the starter is also on the drivers side.

All of the automatics, Crapmaro and S-10, from 2.2 or 2.5 4-cyl or 2.8, 3.1, or 3.4 6-cyl, will bolt up fine to any of the 2.8, 3.1, or 3.4 motors, but the starter pocket is in the dust shield underneath. You will get a working combination, but you may have trouble finding a good dust shield for the long term.

So, if you already have a running 2.8, 3.1, or 3.4 motor, FWD or RWD, check the side the starter is on. If it is on the passenger side, any S-10 transmission and bell housing will work. If the starter is on the drivers side, you will need the bell housing from a early '90's Crapmaro to go with your S-10 transmission, or get the whole transmission and bellhousing from a newer 2.2 S-10. Or you could try to find the transmission from a 2WD 2.8 equipped Isuzu Amigo. Good luck on that one.

As to the intake, any motor with the cast iron heads can use the carb, tbi, or Edelbrock manifolds. If the heads are aluminum, you'll have to fabricate/ modify an intake to make it work, or turn the manifold around backwards on the motor. This won't clear with the stock FWD timing cover/ water pump setup, but will clear the RWD timing cover/ water pump set-up.

If my camera was working, I could get a picture of every one of these combinations out in the garage. Anyone need some parts?
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Opelguy, thanks for that wealth of info! Looks like my old 2.8 might work afterall.

As for the ditching the Opel motor: The 1.9 is a good motor, but a 2.8 has more potential. The 2.8 won't make it a 400HP muscle car, that's what my Buick is for, but I need a little more than the 1.9 can resonabally do. I'm not one for keeping anything stock/original, unless it's a particularly rare peice, or of some automotive historical value. The lack of parts for these motors also make me want something else. I know that you can get alsmost anything for it, but I like being able to goto my local parts store and order anything I need. I'm making a trip to the junkyard in the next few days, so I'll check around for S-10 transmissions.

A for the carb, I'll have to do a little more research into it.

Stephen, I was going by what the new crate aluminum engines were described as on the GM website. Although I don't remember the exact wording, there was a very decisive application for these engines. So, if all engines fit the trannies in this application, the only thing left is to decide which of the bellhousings, hydraulic or manual, and T-5 tranny, tail shaft shifter or body shifter can be used. Neat. I've got the late Camaro 3.4 with a 92 S-10 T-5 and an 88 bellhousing, so I can put the shifter in the console hole and use the manual clutch mechanism. All I had to do basically, was to move the S-10 tranny mount back 2 1/2 inches from the stock automatic mount holes, and drop it 3/4 of an inch. From there, getting the longitudional angle for the engine mounts was an easy step. The engine mounting plates were a little harder, but now it's all done and waiting for sheetmetal trimming to install.


Before anyone goes crazy here buying a ton of parts, there ARE a couple of issues you might not know about that need to be addressed befor this swap is undertaken:

The stock RWD manifolds are heavy, fat, and angled all wrong for the Opel. The FWD ones have one side cross over the top of the bell housing and join with the other, then dump out the bottom. Unfornutaly neither will work well in the Opel. The only other option is the Fiero manifolds, which dump straight out the front or back of the engine, either into the firewall or the fan. If you're willing to run an electric fan, you can use these manifolds to dump to the front, then drop one underneath to meet up with the other. If the starter is on the passenger side, you can run the exhaust ofer the top of the passenger manifold and along the firewall down the back passenger side of the motor. Then run your exhaust. as normal. If the starter is on the drivers side you might be able to do the same and run the exhaust out below the manifold. Be advised that the fiero manifolds are very hard to come by, and they seem to fetch a premium. (Also, I really need a set, so if anyone runs across a set I would be VERY grateful.)

Please mount the starter to the motor before you fabricate any crossmembers or mounting fixtures. It goes pretty far forward along the motor and it needs to be taken into account when your doing all this work. In a Manta or Kadett it won't clear the suspension crossmember.

Oil filter:
The oil filter mount comes out the side of the block exactly where the motor mounts would need to be. The mount can be rotated, and the FWD units are a lower profile and longer to give you more clearance, but it will be an issue. Alternatly, the FWD ones can be cut off and drilled and tapped to hook up hoses and remotely mount the filter.

Good luck, let me know if you need more info.
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Stephen, on my 3.4 there was a pinned adapter for the oil filter that puts the oil filter front to rear and clears the motor mount area. I had to drill out the motorplate for access to the oil pressure plug forward of the adapter plate. One other thing that I have written about is the bolt bosses for the driver's side of the block are not on the same plane. There is a difference of 1/4 inch between the two top bolts and the single bottom bolt. The starter I got for a 3.4 bolted right up and shimmed out correctly, there was no interference with the engine crossmember at all. The passenger side engine plate had to be trimmed a lot because of the casting shape above the oil pan. I couldn't understand why the plate wasn't working after I was so careful in laying it out. Then I looked under the plate and found the problem. I couldn't see the tree for the forest. Hopefully, the engine will be in the car again, next week, I hope, I hope, I hope.

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