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Discussion Starter · #1 · (Edited)
Was out playing with the car over last weekend and it looks like I'm burning oil both at startup and during normal driving (rebuilt it myself a few years back, not surprised but just a little disappointed).

I'm going to start digging into valve stem seals some nice weekend coming up, but I think I'm going to start sourcing another engine to fix up so I have less downtime in the event I need to dig into the 2.5 that's in the car right now. If I'm going to rebuild another one anyway I was thinking I might as well soup it up or look into a 3.0l swap, which direction would you go and why? Looking around it looks like there are a few manufacturers making hotter cams but I don't see much as far as pistons go. I have a buddy with a spare Megasquirt laying around as well which could be fun...

Thanks,
Brendan
 

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These get expensive to build. $1000 cam sets, nearly that for pistons (JE does customs). Even the gasket sets get pricey. However, they are easy to work on as far as full rebuild goes. For budget conscious, a stock rebuild with MegaSquirt would be effective and nice.

Improved power to dollar value will always lie with forced induction. Given the MS option you can easily get over the L-Jet limitations. Either turbo like the Calloway or Eaton super charger. Internal components don't need to be changed, but you can cut down the stock pistons for a bit lower compression if you want. There have been several who have made simple supercharger systems on the LH side of the car. Mine is a bit more complex and on the RH side. I think my total build cost was around $5-6000 for the engine. Lots of reused / reconditioned parts and I had access to tools for fabricating some of the custom parts.
 

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Maybe you can find a decent 3.0 motor for not too much dough and then you have a straightforward swap and a nice increase in torque. You can then go for more with Megasquirt and a pair of cams at a later date.
 
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Have you done any tests to determine whether it is the valve guides/seals or the piston rings are the cause of the oil consumption? A compression and leakdown test will often show ring sealing issues (high leakage past the rings will show up as an audible air leak at the oil filler).

Valve guide/seal issues cannot be determined by compression/leakdown tests in most cases, but if your oil consumption is heavy (say a quart every few hundred miles), this can be demonstrated by decelerating the engine in gear for several seconds, then applying full throttle: if a large puff of grey-blue smoke emits from the tailpipe when the throttle is opened, you have a guide issue. If this is the case, you can likely get away with only a top end rebuild. If you get heavy smoke during hard acceleration in any case, then it is more likely to be a ring issue.
 

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If you are leaning toward swapping in a 3.0L from a Milano Verde, and are close to New England, I have an extra I'd let go of. I have that same conversion in an '84 GTV6 in my yard. Only about 30HP more than a 12v 2.5, but the added torque is noticeable. Good luck with whichever direction you choose to go. I also have a spare 2.5L if you want to keep your car on the road while puttering on a V6 engine separately.

Cheers, Peter
 

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I tend to think a 3.0 swap is the way to go. Of course I'm biased as that is the way I decided to go. It's a relatively cheap way to gain 30 horses and approximately the same increase in torque.

If you can find one that does not need a lot of work, I'd just reseal it and stuff it in. I should have done that, as I've spent considerable sums on higher compression pistons and liners, a couple of sets of cams (including a couple of hot rod RJ cams). I've also picked up a standalone from Al Mitchell, configured to be a plug in to the stock harness...plus a few additional goodies.

Bob
 

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If you are leaning toward swapping in a 3.0L from a Milano Verde, and are close to New England, I have an extra I'd let go of. I have that same conversion in an '84 GTV6 in my yard. Only about 30HP more than a 12v 2.5, but the added torque is noticeable. Good luck with whichever direction you choose to go. I also have a spare 2.5L if you want to keep your car on the road while puttering on a V6 engine separately.

Cheers, Peter
How hard is the 3L swap - and would you do it over the 24v upgrade?
 

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I'm not the ultimate expert on this, but I may have some insights to add. I have an '84 GTV6 in the yard with a 3.0 Verde in it. I didn't do the conversion. But that's pretty much a plug-and-play operation. The additional toque is noticeable.

As I understand it, using a 12v 3.0 from a 164 does add some extra dinking to the process. I think converting this FWD engine to work in a RWD chassis will require Frankensteining some parts from a 2.5 onto the 3.0. Like: swapping the oil sump/pan and the oil pickup/pump from the 2.5 onto the 3.0. Maybe the face plate on the front of the engine too? I have heard that ALFA upgraded the valve gear on the 164 engines tho (maybe stronger rockers?). May require modifying the exhaust headers too?

I'm currently working at a creeping pace on a 24v 4 cam 3.0 164 LS/Q conversion into an '86 GTV6. From my research on this project, this transplant requires considerably more attention! The larger heads won't clear the GTV6 brake servo barrel. So you have to find a pedal box and servo booster from an Alfetta to swap in. Turning the FWD engine 90 degrees will then require custom-made headers to line up with the RWD exhaust (stock 24v headers have oval ports at the heads, so you have to use the original manifold flanges to start). There are several options on what needs to happen with the intake plenum. Some have used two center mount GTV6 plenums grafted into one larger unit. Some have modified the 164 unit to work. Oil sump and oil pump swap applies here too. Ideally, you may also want to move the oil filler cap to a different location where it's easier to access. There's a bunch more to it than that. But that should be enough to help your decision on which way to jump.

The 24v 164 3.0LS has 210HP with the Q version (45mm intake runners vs 39mm). With a good design on the new headers plus a performance exhaust, you might arrive at 250HP. That's about 100HP over a stock 12v 2.5. That's about as far as I'm prepared to go, unless I opt for MegaSquirt at some point. You'll still have the same drive train, and I'm not sure how much more power those components can take without asking for trouble? Clutch, guibos, gearbox, diff, etc.

Hope that was some help.

Peter
 

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I'm not the ultimate expert on this, but I may have some insights to add. I have an '84 GTV6 in the yard with a 3.0 Verde in it. I didn't do the conversion. But that's pretty much a plug-and-play operation. The additional toque is noticeable.

As I understand it, using a 12v 3.0 from a 164 does add some extra dinking to the process. I think converting this FWD engine to work in a RWD chassis will require Frankensteining some parts from a 2.5 onto the 3.0. Like: swapping the oil sump/pan and the oil pickup/pump from the 2.5 onto the 3.0. Maybe the face plate on the front of the engine too? I have heard that ALFA upgraded the valve gear on the 164 engines tho (maybe stronger rockers?). May require modifying the exhaust headers too?

I'm currently working at a creeping pace on a 24v 4 cam 3.0 164 LS/Q conversion into an '86 GTV6. From my research on this project, this transplant requires considerably more attention! The larger heads won't clear the GTV6 brake servo barrel. So you have to find a pedal box and servo booster from an Alfetta to swap in. Turning the FWD engine 90 degrees will then require custom-made headers to line up with the RWD exhaust (stock 24v headers have oval ports at the heads, so you have to use the original manifold flanges to start). There are several options on what needs to happen with the intake plenum. Some have used two center mount GTV6 plenums grafted into one larger unit. Some have modified the 164 unit to work. Oil sump and oil pump swap applies here too. Ideally, you may also want to move the oil filler cap to a different location where it's easier to access. There's a bunch more to it than that. But that should be enough to help your decision on which way to jump.

The 24v 164 3.0LS has 210HP with the Q version (45mm intake runners vs 39mm). With a good design on the new headers plus a performance exhaust, you might arrive at 250HP. That's about 100HP over a stock 12v 2.5. That's about as far as I'm prepared to go, unless I opt for MegaSquirt at some point. You'll still have the same drive train, and I'm not sure how much more power those components can take without asking for trouble? Clutch, guibos, gearbox, diff, etc.

Hope that was some help.

Peter
Peter

You’re always a great help. Awesome write up sir.
 

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I'm blushing. Each of those 3 options requires more than I included, but should help on a decision between ease of task vs more HP and more work involved. I think even the Verde swap may need a spacer on the flywheel to get the starter properly engaged. Once you've made your final decision, others here can help walk you thru more details.
 

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My Personal choice is the 2.5, though I like the extra torque and a few extra horses of the 3.0, the 2.5 sings a sweeter song, it revs higher easier and I find it more fun playing on back roads with them. The 3.0 does noticeable extra low end torque, but it loses it by 6K rpm, whereas the 2.5 sings right up to 7K plus rpm.
 

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Has anyone here rebuilt their 2.5 to 2.8 as in the '80s Gleich conversions? I think they used bigger bore pistons/barrels and different rods, but the same crankshaft. 2.8 with S cams sounds nice, unless the pistons/barrels and rods are particularly rare and expensive.

I already own a "fast" car and drive much faster ones at work, so I don't feel the need to make my '81 GTV6 much faster, but maybe better throttle response and a bit more oomph without losing its character or sound.
 

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The 3.0 does noticeable extra low end torque, but it loses it by 6K rpm, whereas the 2.5 sings right up to 7K plus rpm.
The rev limiter in the L-Jet computer does not allow you to go to 7000 rpm. From memory it is set at 6200 rpm. It can be turned up by changing the value of a resistor on the circuit board. There is also a rev limiter in the ignition computer that is set higher and is almost impossible to change.
My 3L got Magasquirt with adjustable rev limiters and it revved faster than the 2.5 ever did but it was unnecessary since even with hot cams the power curve was pretty much flat at over 200 RWHP from 5200 to 7000. I finally set it at 6500 rpm.
 

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"The rev limiter in the L-Jet computer does not allow you to go to 7000 rpm. From memory it is set at 6200 rpm."
I have always run modded boxes with the rev limiter removed. I had a couple Zat boxes with that. It always bothered me hitting the limiter, and didn't seem the best thing for the engine either.
 
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