Anyone been able to nail down some specs for Mark IV 454 engines?

[Mr_Ryumaru]

alright guys, heading out shortly to go get some more pics. Gonna clean the casting number and figure out what it actually is, take some pics of the mains, some pics of the pistons, as well as pics and measurements of the valves and such. Anything else I should grab? Also, thank yall so much, you guys are always super helpful, and just downright awesome to deal with <3

 

[4WDKC]

www.mortec.com can help you decipher the numbers on the engine.

 

[Mr_Ryumaru]

Alright guys, got a bunch of pics below for you. Cleaning up the casting number revealed a hidden digit. The number is "3999289", which checks out on the list linked earlier in the thread. However, the list doesn't say anything about it so any additional info would be greatly appreciated. So, below are the pics and a brief description of what they are.

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Picture of the mains showing this is a two bolt block. I'm fine with that, I've been told you can take these to 500hp easy, and I do plan to convert it from bolts to studs. Also, some day down the road I can convert it to a 4 bolt, but I doubt I'll ever make enough power to warrant doing so.

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Picture of the piston. Not sure if these indents are typical, or if they're an aftermarket design. Would love input on that. I am fairly certain they're aftermarket bought though, based on the shape they're in. Regardless, I will be reusing them as they are in phenomenal condition and I'm also on a budget here.

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Horrible picture, sorry. But I'm just curious what "Hi-Perf" means? I would love to thing it means high performance, but I am skeptical

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Picture of the cylinder heads. Rough measurement showed the intake to be ~ 2 1/8", and the exhaust to be ~1 3/8, now these weren't exact as it was hard to get the caliper in there. That said it is definitely within 1/16 to true size. Are these stock sizes?

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As requested, a detailed picture of the valves springs. I did not realize the springs were a double spring design before. But I know that some engines come stock with double springs so idk if these are stock or not. Opinions?

So that's it, I have some other pictures if any are needed, but I think these cover everything requested. Thanks again guys, and can't wait to hear your thoughts.

 

[nvrenuf]

"HI-PERF PASS" isn't anything to get excited about, all passenger blocks have that (tall deck blocks say "TRUCK"). Everything looks good and typical Mark IV bbc, no idea on the pistons though. Clean the carbon off of the pistons, if aftermarket they'll likely have a part number stamped in them.

 

[Mr_Ryumaru]

Yeah I kinda figured. The things I'm most interested in are whether the valves are stock size, whether the pistons are domed enough to make better compression, and finding out more about this specific block. I'm not really concerned with the valve springs as I'll be running a lunati cam and will likely run whatever they reccomend.

Also, what's the difference between tall and short decks? And since this engine had no casting saying truck, does that mean it came out of a car? Sorry if these are stupid questions, still learning the way of the chevy

EDIT: In regards to tall vs short deck, google was my friend. I also understand that by "truck", they mean things like dump trucks. And while tall decks are more heavy duty, a short deck in a pickup is normal. But some searches did reveal that
3999289 is a great block to bore out and make stupid power. Not the path I'm going, but hey maybe some day. Feel free to correct me if I'm wrong on any of that. Always willing to learn more.

Still would love input on the pistons and valves. Also, still haven't found a factory power rating for this block :/

EDIT #2: Well, turns out I'm a jackass. In regards to the pistons, those would be valve reliefs and I'm an idiot for not realizing that. All thats left is valve size, but given the rest, it's probably stock. I'm just gonna go ahead and guess that this engine probably made 230hp stock like the various sites say. Might look into some different pistons, but I mean good grief they're spendy

 

[QBuff02]

Yeah I kinda figured. The things I'm most interested in are whether the valves are stock size, whether the pistons are domed enough to make better compression, and finding out more about this specific block. I'm not really concerned with the valve springs as I'll be running a lunati cam and will likely run whatever they reccomend.

Also, what's the difference between tall and short decks? And since this engine had no casting saying truck, does that mean it came out of a car? Sorry if these are stupid questions, still learning the way of the chevy

EDIT: In regards to tall vs short deck, google was my friend. I also understand that by "truck", they mean things like dump trucks. And while tall decks are more heavy duty, a short deck in a pickup is normal. But some searches did reveal that
3999289 is a great block to bore out and make stupid power. Not the path I'm going, but hey maybe some day. Feel free to correct me if I'm wrong on any of that. Always willing to learn more.

Still would love input on the pistons and valves. Also, still haven't found a factory power rating for this block :/

The pistons look like a run of the mill aftermarket "flat top", like a speedpro/trw or such. they'll probably only give you in the neighborhood of 8:1 compression with those heads, i'd recommend going to domed pistons (if budget allows) if you want to make any kind of power and certainly if you want to take advantage of any camshaft upgrade. I am running a +25cc domed trw in mine and with the work and block/head milling i'm right around 10:1-10.25:1 on compression. Looks like you also have stock size valves, which isn't all that bad. depends on how much you want to spend to upgrade to larger valves. I'd still caution to have the heads knocked apart and checked out before you got crazy with them, just knowing what I know about the valve seat issues. If you're going to run an aftermarket cam than I would definitely recommend a change to different valve springs. specifically whatever the cam card calls for when you pick one out. unless you decide to purchase a complete cam kit, then it'll come with whatever it works with. As far as tall deck/short deck, the tall deck truck block has a deck height of 10.2 inches, where a standard short deck block is only 9.8 inches. that's the distance between the crankshaft journal and the head mating surface of the block. Lots of pullers and super high performance applications run tall deck blocks for utilizing big stroker crankshaft assemblies. As for the valve springs you have, they look like stock valve springs with a damper spring, and depending on the pressures they have, and giving them a correct installed hieght, you could possibly use them with a small performance cam, but more along the lines of an rv type cam. Also, there's absolutely nothing wrong with a 2 bolt main block for most applications. I was prepared to build mine exactly like I did without knowing what I had, figuring on a 2 bolt. I just got lucky and it was a 4 bolt block when I took the pan off, at least something went right for me in that regard, everything you have so far looks to be a solid foundation for any build route you decide to go down.

 

[Mr_Ryumaru]

The pistons look like a run of the mill aftermarket "flat top", like a speedpro/trw or such. they'll probably only give you in the neighborhood of 8:1 compression with those heads, i'd recommend going to domed pistons (if budget allows) if you want to make any kind of power and certainly if you want to take advantage of any camshaft upgrade. I am running a +25cc domed trw in mine and with the work and block/head milling i'm right around 10:1-10.25:1 on compression. Looks like you also have stock size valves, which isn't all that bad. depends on how much you want to spend to upgrade to larger valves. I'd still caution to have the heads knocked apart and checked out before you got crazy with them, just knowing what I know about the valve seat issues. If you're going to run an aftermarket cam than I would definitely recommend a change to different valve springs. specifically whatever the cam card calls for when you pick one out. unless you decide to purchase a complete cam kit, then it'll come with whatever it works with. As far as tall deck/short deck, the tall deck truck block has a deck height of 10.2 inches, where a standard short deck block is only 9.8 inches. that's the distance between the crankshaft journal and the head mating surface of the block. Lots of pullers and super high performance applications run tall deck blocks for utilizing big stroker crankshaft assemblies. As for the valve springs you have, they look like stock valve springs with a damper spring, and depending on the pressures they have, and giving them a correct installed hieght, you could possibly use them with a small performance cam, but more along the lines of an rv type cam. Also, there's absolutely nothing wrong with a 2 bolt main block for most applications. I was prepared to build mine exactly like I did without knowing what I had, figuring on a 2 bolt. I just got lucky and it was a 4 bolt block when I took the pan off, at least something went right for me in that regard, everything you have so far looks to be a solid foundation for any build route you decide to go down.

Yeah most people are saying I could take it to 500hp easy with only a stud conversion, so I'm fine with that. The pistons on the other hand, they're like 125-150 bucks a pop, and needing eight of them means Imma be spending a hot chunk if I do it. Just something I'll have to think about. As for the valvetrain, like I said I'll be running a Lunati barebones series cam, and when I'm ready to purchase it I plan to call them up and run whatever they tell me to. I wonder if they could point me in the direction of a good valve size for the cam I'll be running. In case your curiou, these are the planned mods: Headers and dual exhaust, 750cfm Quadrajet, MSD ignition system, Lunati barebones series cam (PN# 10110101LK), and an Edlebrock Performer intake manifold.

The whole idea I'm going with for this entire build is sort of "waking" up the motor/truck. You know, make more power but not make power the point of the build. And I want this thing to be reliable and solid, and the more power you make the more risk you run (too a point). So it's certainly a rabbit hole deal of how far do I want to go. I mean, realistically I can just wait longer to save more. But this truck is intended to replace my daily while I restore it, and she's getting pretty tired already so I really don't want to delay for too long.

 

[Mr_Ryumaru]

The pistons look like a run of the mill aftermarket "flat top", like a speedpro/trw or such. they'll probably only give you in the neighborhood of 8:1 compression with those heads, i'd recommend going to domed pistons (if budget allows) if you want to make any kind of power and certainly if you want to take advantage of any camshaft upgrade. I am running a +25cc domed trw in mine and with the work and block/head milling i'm right around 10:1-10.25:1 on compression. Looks like you also have stock size valves, which isn't all that bad. depends on how much you want to spend to upgrade to larger valves. I'd still caution to have the heads knocked apart and checked out before you got crazy with them, just knowing what I know about the valve seat issues. If you're going to run an aftermarket cam than I would definitely recommend a change to different valve springs. specifically whatever the cam card calls for when you pick one out. unless you decide to purchase a complete cam kit, then it'll come with whatever it works with. As far as tall deck/short deck, the tall deck truck block has a deck height of 10.2 inches, where a standard short deck block is only 9.8 inches. that's the distance between the crankshaft journal and the head mating surface of the block. Lots of pullers and super high performance applications run tall deck blocks for utilizing big stroker crankshaft assemblies. As for the valve springs you have, they look like stock valve springs with a damper spring, and depending on the pressures they have, and giving them a correct installed hieght, you could possibly use them with a small performance cam, but more along the lines of an rv type cam. Also, there's absolutely nothing wrong with a 2 bolt main block for most applications. I was prepared to build mine exactly like I did without knowing what I had, figuring on a 2 bolt. I just got lucky and it was a 4 bolt block when I took the pan off, at least something went right for me in that regard, everything you have so far looks to be a solid foundation for any build route you decide to go down.

Aaaaaaaaaaaaaand once again, I'm an idiot. the price of ~150 was for a set of eight, so **** it, why not. You got a link to or part number for yours, just so I can get an idea of what to look for?

 

[bucket]

Even a low compression, stock headed 454 will respond well to a mild cam, intake and headers.

But a boost in compression certainly won't hurt.

 

[Mr_Ryumaru]

Even a low compression, stock headed 454 will respond well to a mild cam, intake and headers.

But a boost in compression certainly won't hurt.

Thats my mentality. If I can find or be recommended a set for around the $250 range I would be alright with spending that much.

 

[shiftpro]

First of all Sean, you can't be that stupid or you would be asking questions on a Ford forum.

 

[shiftpro]

Even a low compression, stock headed 454 will respond well to a mild cam, intake and headers.

But a boost in compression certainly won't hurt.

Well... a little yes. But the mods you mentioned would make much more of a positive improvement with some compression behind it all.
Also, depends on the heads... crappy low compression and low flowing heads will not 'wake up' with cam and exhaust work as much as something that flows... like 781s or 049s like he has.
Not trying to start an argument bucket, just pointing out how these mods don't do the same for every engine.

 

[shiftpro]

Aaaaaaaaaaaaaand once again, I'm an idiot. the price of ~150 was for a set of eight, so **** it, why not. You got a link to or part number for yours, just so I can get an idea of what to look for?

$150 is too low. Must be cast junk. Not all cast is junk btw. You should spring for forged pistons everytime.

 

[shiftpro]

The pistons look like a run of the mill aftermarket "flat top", like a speedpro/trw or such. they'll probably only give you in the neighborhood of 8:1 compression with those heads, i'd recommend going to domed pistons (if budget allows) if you want to make any kind of power and certainly if you want to take advantage of any camshaft upgrade. I am running a +25cc domed trw in mine and with the work and block/head milling i'm right around 10:1-10.25:1 on compression. Looks like you also have stock size valves, which isn't all that bad. depends on how much you want to spend to upgrade to larger valves. I'd still caution to have the heads knocked apart and checked out before you got crazy with them, just knowing what I know about the valve seat issues. If you're going to run an aftermarket cam than I would definitely recommend a change to different valve springs. specifically whatever the cam card calls for when you pick one out. unless you decide to purchase a complete cam kit, then it'll come with whatever it works with. As far as tall deck/short deck, the tall deck truck block has a deck height of 10.2 inches, where a standard short deck block is only 9.8 inches. that's the distance between the crankshaft journal and the head mating surface of the block. Lots of pullers and super high performance applications run tall deck blocks for utilizing big stroker crankshaft assemblies. As for the valve springs you have, they look like stock valve springs with a damper spring, and depending on the pressures they have, and giving them a correct installed hieght, you could possibly use them with a small performance cam, but more along the lines of an rv type cam. Also, there's absolutely nothing wrong with a 2 bolt main block for most applications. I was prepared to build mine exactly like I did without knowing what I had, figuring on a 2 bolt. I just got lucky and it was a 4 bolt block when I took the pan off, at least something went right for me in that regard, everything you have so far looks to be a solid foundation for any build route you decide to go down.

Good advice here.
IMO the flat tops may be fine to use. There is a lot of meat on the deck to remove. The deck should be surfaced anyway. Talk to your engine builder/machinist about decking the block down to zero deck height. Enough material can be removed to make a difference in compression, as does the compressed thickness of the head gasket. If they were dished pistons... forget it and toss them. But don't be so hasty to dump flat tops yet.

As for your heads... if you're on a budget but want more (don't we all?), consider installing larger exhaust valves before intake. Stock intake and larger exhaust will make more difference than vicy versy. There will be some porting work too, the bowls should be hogged out to go vertically straight down.
You don't want to see and taper in the bowls. The valve guide bosses can be cut down some, maybe don;t go to crazy thinning out the bosses as this is where these heads like to crack.
Go with solid bronze guides... not the cast guides with a bronze liner.

 

[shiftpro]

Have you considered the fuel you will use?
Are you interested in perhaps using propane?
Then you can throw serious compression at it.
And a fun bonus will be the tree huggers who will compliment you on your vintage truck with clean propane...heh heh... not knowing you have 450hp.