Classic 2.4L Swap

[RallyBob]

Originally Posted by Gumby Also the flywheel on my 2.4 is distinctly different than the 40lb+ monster described elsewhere here on the forums.

You may have gotten a passenger-car version of this engine then (Omega IIRC). The Frontera version (SUV) had the heavy dual-mass clutch/flywheel setup.

But as Hiro said, the pistons are 'très fragile'. He has the oil pan full of ring lands to prove it!

[Gumby]

Originally Posted by RallyBob You may have gotten a passenger-car version of this engine then (Omega IIRC). The Frontera version (SUV) had the heavy dual-mass clutch/flywheel setup. But as Hiro said, the pistons are 'très fragile'. He has the oil pan full of ring lands to prove it!

It's from a Omega A 2.4i (automatic). OGTS doesn't carry forged pistons for the 2.4 but are there any forged pistons in the US that can be made to fit?

[Hiro]

Originally Posted by RallyBob You may have gotten a passenger-car version of this engine then (Omega IIRC). The Frontera version (SUV) had the heavy dual-mass clutch/flywheel setup. But as Hiro said, the pistons are 'très fragile'. He has the oil pan full of ring lands to prove it!

oh yes you may even say "fragile comme du verre" Bob!
I've cleaned the ring land bits in my oil pan but there are more coming from nowhere,
btw I have lots of stock 2.4 pistons for sale now...

[opelwasp]

Originally Posted by Gumby It's from a Omega A 2.4i (automatic). OGTS doesn't carry forged pistons for the 2.4 but are there any forged pistons in the US that can be made to fit?

Yes, call Venolia and they can make you some. I have heard they cost about $100 each to have made. Not bad when a new stock set of cast cost the same.

[RallyBob]

Originally Posted by opelwasp Yes, call Venolia and they can make you some. I have heard they cost about $100 each to have made. Not bad when a new stock set of cast cost the same.

And FWIW, I have had made the following pistons for the Opel 2.4 from Venolia:

8.5:1 turbo design - lowered ring stack, HD pins.
9.8:1 dished piston - tool steel pins (same as Samdog's and Neuropel's)
11:1 domed piston - tool steel pins (actually Duane had these made, I just helped a bit to co-ordinate it)

So they have the program on file. The only catch is these have been all 97 mm bore (2512 cc's new displacement). If you want 96 mm, it would be an easy request because the don't need to re-invent the wheel! They were all designed for 1.94"/1.60" Chevy valves and much bigger cams than stock, so there's tons of valve clearance.

Bob

[Gumby]

Originally Posted by RallyBob And FWIW, I have had made the following pistons for the Opel 2.4 from Venolia: 8.5:1 turbo design - lowered ring stack, HD pins. 9.8:1 dished piston - tool steel pins (same as Samdog's and Neuropel's) 11:1 domed piston - tool steel pins (actually Duane had these made, I just helped a bit to co-ordinate it) So they have the program on file. The only catch is these have been all 97 mm bore (2512 cc's new displacement). If you want 96 mm, it would be an easy request because the don't need to re-invent the wheel! They were all designed for 1.94"/1.60" Chevy valves and much bigger cams than stock, so there's tons of valve clearance. Bob

Thanks for the information. $100ea isn't a terrible price… a lot better than trying to get some from Germany! I am going to have to wait on the pistons, at least until I start shipping the flanges. Maybe I'll find the stock 2.4 satisfying

[Gumby]

I was dinking around last night with seeing what it is going to take to remove the fuel tank from my GT. It occurred to me that you could probably get away without installing a "true" hard return nipple on the fuel tank. It seems to me that it would be possible to run a hard line up to the normal tank inlet and pipe the line through the rubber connecting the top of the tank to the metal tube that runs up to the gas cap. If you pipe the line down close to the bottom of the tank I think it would avoid the obnoxious rainfall sound you'd otherwise get.

Am I explaining that well enough? Thoughts or concerns?

[namba209]

Gumby, that fuel tank/neck line is not a good place to install a return line. I put a fitting in the filler neck, below the vent line fitting. My original plan was to just weld a 90 degree 1/4" tube in the filler neck that would protrude below the steel filler neck , and then hose clamp a fuel line to the bottom of the tank. That fell through the cracks when the line broke off at the weld. Hint: don't use old brake lines and try to weld them in place. I ended up just welding a steel barbed fitting below the vent line fittting and running my FI return lines to it. It works just great and I don't here any fuel running back to the tank at all, except with the gas cap off and my ear close to the hole. I'm running a 70 psi fuel pump and my fuel rail relieves at 50 psi. HTH.

[Gumby]

Originally Posted by namba209 Gumby, that fuel tank/neck line is not a good place to install a return line. I put a fitting in the filler neck, below the vent line fitting. My original plan was to just weld a 90 degree 1/4" tube in the filler neck that would protrude below the steel filler neck , and then hose clamp a fuel line to the bottom of the tank. That fell through the cracks when the line broke off at the weld. Hint: don't use old brake lines and try to weld them in place. I ended up just welding a steel barbed fitting below the vent line fittting and running my FI return lines to it. It works just great and I don't hear any fuel running back to the tank at all, except with the gas cap off and my ear close to the hole. I'm running a 70 psi fuel pump and my fuel rail relieves at 50 psi. HTH.

I'll say it isn't the best place to install it but it certainly the simplest place to install it (no welding since the lower section isn't metal on mine). My fuel pressure is considerably lower than yours. The intention was to have the swirl pot (surge tank) bleed off extra fuel to the "neck line" as you called it so it would only be under the excess pressure of the low pressure/high flow pump that feeds the swirl pot. Pressure returning to the main fuel tank would be relatively low.

Can you explain why that is not a good place to install a return line?

[oldopelguy]

The return line really doesn't need to go back to the tank, it can just go back to the suction of the filter immediately before the pump. After all, the pump is by definition going to be sucking more out of the filetr than coming back on the return line, so there will still be a net suction from the tank. Easiest would be to use ono of the mechanical EFI return-type filters from Speedway or the like:
Fuel Filter with Return

One disadvantage to returning the fuel to the filler neck is the constant running water sound, which may or may not bother you, from the fuel splashing down into the tank. This isn't really an issue if you run a tube inside to down below the "water line" inside the tank.

[namba209]

Gumby, my reference was to NOT install the return line in te hose connecting the filler neck to the tank spout. It would have the possibility of leaking, since int would be hard to seal a fitting in the hose. On Willit?, I'm running a surgetank/swirl tank just behind the grill, with an overflow return line from it, that "T"s into the high pressure fuel pump pressure relief/bleed port, that "t"s into the fuel rail pressure relief port, that eventually goes to the filler neck of the fuel tank. During normal engine running, or at any time the pumps are on, I don't have the "running water" sound from the tank, Stephen referred to, unless I pull the gas cap and stick my ear down to the gas filler hole, I'm curious, now that I've read your initial post again. What part of the fuel tank filler neck to the tank is not metal, other than the connecting hose?

[Gumby]

I'm not sure why sealing would be an issue with the connecting hose it you do it correctly but no worries I like the T joint right before the high pressure fuel pump idea a lot better from an installation standpoint. It's a lot cleaner because you only need one fuel line up to the engine compartment. This is why I like bouncing ideas off the forums! Someone else may have a better idea.

[N61WP]

I have got the purple return filter OldOpelGuy has posted. I'll give it a shot. The problem I see is finding enough room for both it and the high pressure pump under there.
Damn Opel engineers that decided to put a fuel tank inside the car without access!
Jc

[Gumby]

Originally Posted by N61WP I have got the purple return filter OldOpelGuy has posted. I'll give it a shot. The problem I see is finding enough room for both it and the high pressure pump under there. Damn Opel engineers that decided to put a fuel tank inside the car without access! Jc

I plan on mounting it up front with the swirl pot. No point in piping that much high pressure lines if you don't have to.

[bigben]

Originally Posted by N61WP Damn Opel engineers that decided to put a fuel tank inside the car without access! Jc

Yeah, but how many rusted out GT tanks have you seen? It may not be easy to access but neither are the connections on a tank exposed to 30 years of rain, dirt, salt and snow!

[Gumby]

I took the engine and transmission out this weekend. It was kind of a pain to do by myself but going back the other way (putting the 2.4 in) shouldn't be as much trouble.

My current plan is to use a low pressure pump to keep a swirl pot/surge tank full up at the front of the vehicle full. Then feeding from the small tank will be a high pressure fuel pump (MSD brand if anyone was wonder) that goes to the fuel rail.

Maybe one of our more experienced opelers can enlighten me on what sized fuel lines they suggest I run for the EFI on the 2.4?

All I have left to buy fuel system related is the connections to the tank up front and the fuel lines themselves.

The clutch issue reared its ugly head again the kevlar clutch plate I purchased off of a member here was broken when it arrived. The springs in the plate itself are broken. So I'll have to figure something else out.

"Yes"! I am aware the 4 speeds gears are not exceptionally strong… but technically speaking neither is the getrag 240 so I am saving my pennies until I determine what transmission/clutch assembly will work best with the future planned supercharged 2.4. Once this is all back together it will be my daily driver until I can get my Honda fixed.

Originally Posted by bigben Yeah, but how many rusted out GT tanks have you seen? It may not be easy to access but neither are the connections on a tank exposed to 30 years of rain, dirt, salt and snow!

I've only ever seen one... it looked brand spanking new when I got back there.

[RallyBob]

Originally Posted by Gumby Maybe one of our more experienced opelers can enlighten me on what sized fuel lines they suggest I run for the EFI on the 2.4?

3/8" (known as -6AN when using the braided stuff) is perfectly adequate. I've seen cars dyno near 450 whp with this size line for road racing, and higher for drag racing.

"Yes"! I am aware the 4 speeds gears are not exceptionally strong… but technically speaking neither is the getrag 240 so I am saving my pennies until I determine what transmission/clutch assembly will work best with the future planned supercharged 2.4.

Have you looked into a Getrag 265? An Opel 6-cylinder version bolts directly to your block and can handle 350+ ft lbs of torque.

Bob

[Gumby]

Originally Posted by RallyBob 3/8" (known as -6AN when using the braided stuff) is perfectly adequate. I've seen cars dyno near 450 whp with this size line for road racing, and higher for drag racing.

Thanks for the suggestion!

Originally Posted by RallyBob Have you looked into a Getrag 265? An Opel 6-cylinder version bolts directly to your block and can handle 350+ ft lbs of torque. Bob

That was my first thought but I think the consensus here was to consider other options because of the bulk and issues procuring the bell housing. Do you know if there are any shifter location issues? It seems for about 3.5k I can get a new "bolt in" transmission plenty strong enough for my requirements but that is a bit more than I want to spend on just the transmission. Variants of the 265 seem to have been used in several US cars so maybe there is an outfit here that can replace the guts with gears more appropriate for a GT and relocate the shifter. I think it is definitely worth looking into.