Dodge 8.0 Differences?

PovertyPony

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I know this topic has been beat to death- but what is the extent of differences between the 8.0 found in the Viper and the 8.0 "Magnum" engine found in Rams? I've been entertaining the idea of the Magnum for another project and wondering how much knowledge would carry over.

Now I know the answer is "they're totally different." They were separate but parallel programs at Dodge both based on the old LA platform. But the question is how different? I know they don't share any parts. But is it like the 5.4 found in the Cobra R or GT compared to the 5.4 found in F150s, where they don't share any parts but they're the same platform, or is it more like the 351 Cleveland compared to the 351 Windsor, where they have absolutely nothing in common but the same displacement? (Ignoring Cleve-or hybrids.)

In particular I wonder about the valvetrain and rotating assembly, since the truck versions seem to leave a lot on the table with those.
 

MoparMap

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I had thought they said the only real similarity between the two was bore spacing or something like that. I think there were only a half dozen part numbers or so that were common between them. That being said, since the 8.0 was based on the LA, I'd wonder if it wouldn't share more in common with the Magnums when it comes to parts. One other thing with the Viper, it might not share actual part numbers with earlier engines, but sometimes those parts do interchange. One example I can think of is the lifters. The Viper lifters are a different part number than the LA lifters, but in theory they are the same parts dimensionally. I believe the Viper ones are held to a much better tolerance though, which could be one reason they have a different number. So Viper lifters could be used in other engines, but other lifters may or may not work in the Viper based on how well they were made.

Generally speaking though, changing from iron to aluminum is going to affect a whole lot of design parameters. Different thermal expansion and strengths are likely going to dictate different structural designs and interacting components.
 
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PovertyPony

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That's exactly what I'm driving at. I've seen guys use rockers, pushrods, and other valvetrain parts from the Viper engine in the truck one- both basically LA based stuff. And same thing with the other engines I mentioned: the GT lash adjusters and followers were different than the run of the mill truck parts, but they fit in place and were a popular upgrade. Same deal with both the Ford Modular and GM LS engines with iron vs. aluminum. Totally different parts, but same families so you could mix and match. Not to mention all the purpose built parts that would be different between a truck and sports car engine, even if they're interchangeable. It would be no surprise the rods are heavier for the lower RPM, higher volume truck versus the higher revving, higher cost Viper, but are they compatible?
 

Viperhunter

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Apparently Hall of Famer **** Winkles who helped develop the V-10 is suppose to be at this event in Pittsburgh. Might be pretty close to you. Could probably get some one-on-one time with him and hear it from thee man.

 
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PovertyPony

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Just a follow up to this one as I ended up taking the plunge and snagging a truck one for another project.

Some of the key differences include-
Cast iron material: Holy **** is this thing heavy
Block mounts: The Viper version uses an "ear" mount more like the old LA engines, whereas the truck has a pad mount that goes to your typical "spool" type mounts. If you're thinking of swapping something with an old LA, it would actually be pretty easy to use a Viper block versus a truck one.
Bellhousing pattern: Definitely seems to use a different bellhousing pattern, looks like the same as the one used in the 6BT trucks. Makes sense since they used the same transmissions between the two.
Accessory drive: Obviously different for packaging reasons, but similar serpentine setups.
Valve covers: Different, but haven't figured if they're interchangeable yet. The truck ones have provision for coil mounts.
Intake manifold: Obviously the truck has a much taller one with stupid long intake runners, making for incredibly low RPM peak torque. Haven't determined if they're interchangeable yet.
Exhaust manifolds: Obviously different rear exit on the truck. Same exhaust port and gaskets though.
Valvetrain/timing: I haven't measured anything but they sure look similar. Obviously cam specs are going to be way different.
Controls: Truck one is batch fire, waste spark. ECUs are different, but externally identical. Not sure how much is similar internally.
Internals: I probably won't get a chance to examine those any time soon (I hope.) I went a different route and rather than trying to improve the internals I decided to take advantage of the 8.6:1 CR, and cram a bunch of boost down its throat.

I still need to take a look at the injectors to see if they're different and by how much.
 

GTS Dean

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The water pumps share identical bolt patterns from G1 to iron truck, but the inlets/outlets differ somewhat. Drive pulleys are about 1/4" different in projection from the back fl_ange.
 

MoparMap

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I watched a YouTube video recently where a guy did a teardown of a trashed truck V10. He did a Viper style one earlier as well, but I believe it was gen 3 (maybe an SRT10 truck as well if I remember the oil pan correctly). I was amazed just how different the two really were as I've never seen an iron truck V10 before. Then again I haven't actually taken apart a gen 1 engine either, but just on the face of it I don't think much swaps over at all. I think I recall the only commonalities between them being something like bore spacing.
 

BoondocSaint

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I watched a YouTube video recently where a guy did a teardown of a trashed truck V10. He did a Viper style one earlier as well, but I believe it was gen 3 (maybe an SRT10 truck as well if I remember the oil pan correctly). I was amazed just how different the two really were as I've never seen an iron truck V10 before. Then again I haven't actually taken apart a gen 1 engine either, but just on the face of it I don't think much swaps over at all. I think I recall the only commonalities between them being something like bore spacing.
I've seen those videos in my suggested YouTube videos, but never got around to them. Seeing a tear down of the two variants definitely has me curious.
 
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