how many of 2.4cis parts can I reuse?

[}{arlequin]

I have an early turbo/3.0 Carrera case, crank, and rods. I'd like to build a short stroke 3.2, maybe a 3.4 motor using those parts.

I also have a healthy 2.4cis motor w/ approx. 40k miles since the rebuild (fully stock spec).

Can I use various parts from the 2.4 for this build up? Cam towers? Can the heads be machined to match the 3.2 or 3.4 flow rate? Better yet, what *CAN* I use in the build up of the other motor?

Is this even worthwhile or would it be better to sell the 2.4 complete? Does parting it out make more sense? (It has the 7R case)

thanks for the opinions

[KobaltBlau]

Stud spacing is different which busts you for easy reuse on a bunch of stuff.

Don't let people talk you into using a 66mm crank unless you're building a track only car, imho

[}{arlequin]

Originally posted by KobaltBlau
Don't let people talk you into using a 66mm crank unless you're building a track only car, imho

i thought that's what most used to get a 3.2ss out of a 3.0
is something wrong w/ that setup?

[KobaltBlau]

no, 3.2ss out of 3.0 doesn't change the stroke which stays at 70.4, while bore goes from 95 to 98.

but its "ss" because the 3.2 carrera is 74.4x95 instead.

The 3.0 carrera/turbo case has smaller journals than an SC, so it is the only case that can use the old 66mm stroke crank from the 2.0/2.2 and also has the later stud spacing.

Because of this, you can build a 2.8SS, which is 66x95, compared with the 70.4x92mm that a 2.8 is normally built on. With the early 930 case (like you have), this 66x95 is more robust than the "normal" 2.8 and potentially higher revving, if in fact the bottom end is the limiting factor. It is also normally legal in classes where the standard 2.8 is legal. This is what drives up the price of these cases.

Some people get all hot and bothered about how high they could rev a 2.8SS for street/track work. My personal opinion is that the valvetrain is usually the limiting factor rather than a 70.4 stroke. as evidence I present the factory 2.8RSR and 3.0RSR motors which were both 70.4 stroke and rev quite high, and the fact that missed shifts on 70.4 and even 74.4 motors cause bent valves a lot more often than rods self destruct.

If I've made any errors, someone please correct.

Cheers,

[}{arlequin]

the case came w/ crank and rods, so I'm assuming it's 70.4

your "don't let people talk you into..." post confused me a little, but now I understand. There's no worry about me going w/ a 66, primarily b/c I already have what I need, and also b/c I'm not interested in going down in displacement. This will be a street motor as well (with only 10-14 track weekends/year), so I'll take all the grunt I can have.

either way, I still need to decide on the p/c's, and find an intermediate shaft for it, but otherwise I was just curious how many of the 'normal' parts (valve covers etc.) I could use from my 2.4

If not many, then I guess it's better to just let that one go in one piece.

[jpnovak]

Dave there is not much that would be used between the two engines. As Andy mentioned the stud spacing for the heads is different. Even if they would fit the valves would be too small to flow enough air. you would also have to go with a later cam tower. I guess the valve covers, fan/shroud would work. The oil cooler too. Any of the parts that bolt onto the longblock for that matter.

YOu are looking at a long road to buying parts. If you only have the crank, rods and case you will be buying parts. It still might be better to find a donor 3.0 to get those parts.

I have a partial set of (5) Nikasil cylinders if you need parts. They would be great with a set of JEs which is what I am saving them for.

[}{arlequin]

thanks Jamie. I figured it'd be easier to find a beat up 3.0 for this. As for the P/C's, I'm still on the fence, maybe I'll get lucky and get RSR pieces, or maybe make the leap into "Nickies".

[jpnovak]

yes, A beat up 3.0 would be a perfect donor. I might know of one in NC if you are interested.

Yeah, I got lucky and found a set of the 98mm RSR PCs. They have been sitting on the shelf for a year now. One day I will have saved enough money to build that engine...

[Walt Fricke]

Harlequin

There is actually quite a lot that you could use from your 2.4 on your early 3.0 should you choose to do so:

The cam carrier, the chain housing, the cam, and all the associated stuff - chains, gears, tensioners, rockers, rocker shafts. Also the oil pump and intermediate shaft and all the gears associated with that. And the oil cooler.

Plus the valve covers. The intermediate shaft end plate. The crankcase breather piece. The various sensors (idiot, oil p, oil T). The case through bolts and nuts (maybe you could not use the thick washers, as then need a beveled outer edge), except, I think, for the nuts for the two bolts which stick out (as studs) behind the oil cooler - I think this case uses the finer thread through bolts. The head studs, washers, and nuts. The engine and surrounding tin, plus the fiberglass engine cover. The various 6 and 8mm nuts and washers and odd bolts. The engine carrier (the assembly that holds the engine to the chassis at the back). Your exhaust system. The alternator and assorted pulleys.

By using your earlier distributor crankshaft gear you should be able to use your distributor (you can just measure the width of the hole the distributor fits in to see if that part is compatible - I don't remember when the distributors got fatter in the shaft area) if the early 3.0s were the start of the "reverse rotation" system the SCs used.

What you can't use are pistons, cylinders, or (unless you are making a wierd motor and are willing to spend a bunch of money, and you say you are not making a weird motor) heads. You could use the springs and their associated hardware from your heads if you purchase raw heads, but not the 2.4 heads themselves.

Although the bolts will line up, you can't realistically use your 2.4T induction in terms of physical compatibility because the injectors on the T are inserted into the heads, and any heads you will buy won't be set up for that.

Your flywheel will be fine if in good shape, but the junk donor 3.0 you might purchase will have a 9 bolt flywheel that you can't use.

Now how much of this stuff you will want to use is an entirely different story. You might want a larger oil pump, like the ones from '77 on as a minimum, especially in a hopped up motor. You might not want to mix and match case stud thread pitch (I sure didn't). You might want to use the SC and later cams and cam carriers because they have 4 bearings and journals of a larger diameter. If the T didn't use the nice exhaust where each side has a 3 into 1 collector which then heads directly back to the muffler (no crossover), that exhaust won't be for you (and for that matter, if you build a 3.4 even the good early exhaust is probably too small).

I'm sort of in your boat (or was - I'm beyond the decision point now). I bought one of these early 930 cases and a 66mm crank as a start on a 2.8. I had bits and pieces from a blown-up early motor and several others. When buying all but one of the case through bolts from a junkyard for $100, and then laying out the better part of $40 for the one they were short plus its hardware, I wondered if I wouldn't have been money ahead buying a junk 3.0. That would have gotten me the heads and cam carriers as well plus a cam and a bunch more stuff.

And of course many folks would not be caught dead reusing nuts and bolts even though only rod bolts and flywheel bolts are on the bottom line must not reuse list.

But I bought Pauter rods and J&E pistons, and will have used 3.0 cylinders nikasiled (alas, the ones I had are Alusil, which adds extra cost to convert to nikasil). I'd have no use for the 3.0 induction. I have some mag chain boxes which should work fine (they do on my aluminum case 2.7 race motor). I was not going to use an SC oil pump and have no need for an oil cooler. So I've quit kicking myself for not going that route.

I suppose if you can trade your 2.4 for a 3.0 (one would think you might be able to sell a good running 2.4, even the not so desireable T, for more than a non-running 3.0 will cost) that might put you money ahead because you will get the top end stuff you need. On the other hand, if you scavange your 2.4 for parts, the case might bring a decent dollar - it should be the most desireable of the 7R mag cases: it is nicely broken in, but because this is the least stressed of these cases (as a T) it is the best for a project motor using that case (as in, for instance, a long stroke 2.8 race motor)

Those are my somewhat lengthy thoughts on your situation.

Walt Fricke

[}{arlequin]

damn Walt, that was nicely detailed. Lots of good info in there, unfortunately it only makes my decision harder.

To complicate things even further, I have a fully assembled, ready to run 3.0 w/ new Euro P/C's and Webers, although the cam is just a mild Webcam 154 grind used for hopping up CIS motors. This motor has 20k miles on it and I'm just itching to put it in. At the same time, when the track season ends, I'm looking at some lag time, and debating whether I should go through TWO engine drops/lifts, or just cannibalize one in favor of building a 3.2 and being done with it.

The reason that I didn't want to touch the 3.0 is because it is absolutely ready, and rebuilt by a reputable shop. Who knows what I'll end up doing once my hands touch it. Hence my plan on dropping in the 3.0 while tinkering w/ the early turbo case. I don't really see a point in taking apart a perfectly good motor just so I can use the turbo case and gain .2 liters.