ATK 5.9 Magnum crate motor horse power

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Sorry to resurrect this thread, but it's a good one. I just picked up a '71 Valiant with 39,800 original miles. It is really solid and has a fresh blue metal flake paint job. I'm excited to have it!

It current has the 198 slant six (yes, not even the 225!) and I'm a power guy so I've been diligently researching crate engines. ATK and Blueprint were on my short list, hence resurrecting this thread. I'm an automotive engineer of 21 years in the Detroit area, so I get pretty deep into the weeds on technical factors.

So... I really want a good bang-for-the-buck motor and I'm drawn to the Magnum-based 408 from Blueprint. My question / concern is that both Blueprint and ATK use the stock Magnum heads which are crack-prone. Why not use (or at least offer for extra) the aftermarket and stronger EQ heads (EQ-CH318A)? They flow better and are much stronger. Also, how much does it really save to go backwards to a flat tappet cam? Aren't there good roller cams that don't cost much more? The Magnum engine block is already set up for roller.

@Johnny Mac - would love any input! Really trust your insight. If that motor had the better EQ heads and a moderate roller, it would be a no-brainer. Could that maybe be a mid-level upgrade between that and the aluminum head roller 408?
I doubt the iron heads that BluePrint installs and warranties for 30m/50k are the same crack prone originals, but I'm sure JohnnyMac will address that concern. I wouldn't hesitate to jump to the more powerful roller cammed engine over the heavier, less powerful FT cammer. It's a lot of bang for the buck.
 
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If you want a pair of those heads from Jegs you better jump on them now because they only have seven left in stock.

Yeah for sure, unless that's just what they have on hand right now and can and will order more. The million dollar question is if the EQ (and probably JEGS) heads are still actively being produced. I don't see why not.

@gzig5 - I would hope so, but then Blueprint should advertise that! They should be shouting that they are the improved thicker, better flowing heads. Their webpage for the motor just says "Magnum cast iron heads". Too generic. But I agree with you, the jump to the roller cam aluminum head 408 is probably the way to go for $1,300. But still, that's not pocket change.
 
@gzig5 - I would hope so, but then Blueprint should advertise that! They should be shouting that they are the improved thicker, better flowing heads. Their webpage for the motor just says "Magnum cast iron heads". Too generic. But I agree with you, the jump to the roller cam aluminum head 408 is probably the way to go for $1,300. But still, that's not pocket change.

Just a few more peanut butter jelly sandwiches for lunch....
There are certain times when I will "buy once, cry once" and the engine build is one of them. False economy to do it otherwise, IMO. I do a lot of stuff on the cheap in order to save for the really important things. Motor and brakes are high on my list of getting the best I can. Either way, from what I've seen you'd be happy with either of their offerings.
 
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@GFlo pretty clear from the link you posted (lower pic) that the ch318a and ch318aa (assembled) are the only heads they are selling. Neither of which they list as a performance variant.

From engine quests old catalog, (upper pic) the ch318b and ch318ba were the performance variants and are not listed. I am not sure what the casting differences are other than some dual intake bolt pattern options. But both are listed as “performance”.
 
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The CH318A and B are the exact same head with one difference: the A is tapped for the Magnum-style straight down intake manifold bolts and the B is tapped for the original LA-style 45 degree angle. (As you said, the second letter (AA and BA) just means assembled w/ valves & springs.)

The EQ head was an aftermarket replacement head but they were smart and made it flow more while they were at it and made it to be tapped with either style intake manifold. Very smart on their part. (Not sure why they sometimes called one Performance; they were inherently higher performance from the start.)

I looked at the EQ318 and JEGS head side by side (below). Now I'm not so sure. There are definitely casting differences. Does JEGS really make their own head?

EQ-left-JEGS-right-heads
 
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Hey all,
Sorry took me a min to see the tag and jump in!
You would be surprised at the jump from a flat tappet cam and lifter setup, to a roller. Keep In mind also, as a performance company, I would much rather sell an aluminum headed engine, that starts an a nice clean aluminum casting, than reman anything. If we added a roller, iron headed engine, right in between the current 408's it would make the aluminum headed engine even more of a "no brainer" as the cost separation would be even less between the two. I know we mopar guys dont have a ton of choices out there, but at the same time we need to know a good value add when we see it too. I wouldn't intentionally put an iron head on anything at this point in the game. And since we are so far removed from a reman company, the cost savings vs reward just isnt there.
If you have never had a roller cam, it's one of those "will never go back" type upgrades. That new BPC4085CTCD engine is such a screamer compared to the LA engine it replaced.
I will gladly help ya with a little when the time comes to order on the aluminum headed engine. As far as the head castings and such. We buy the aluminum ones from edelbrock bare, and we then clean them up and assemble them in Nebraska our way, with our valves and contents. The iron ones, I will honestly have to look and see if those are OE castings or aftermarket. The iron headed engine is not a super popular engine, and i didnt help design it, so i dont have it memorized like i do my bpc4085.

I'm just on my phone right now, and will hop back on to read all the questions on PC in a bit.

Thanks for the callout and interest
 
Cool. Thanks Johnny! Yes, the $1,300 current price difference between the iron head flat tappet 408 and the aluminum head roller 408 is a screaming deal. No argument there. Telling myself to suck it up and clip coupons!

Hypothetically... if several of us wanted to buy one at the same time would BluePrint do a volume discount deal?
 
Hey all,
Sorry took me a min to see the tag and jump in!
You would be surprised at the jump from a flat tappet cam and lifter setup, to a roller. Keep In mind also, as a performance company, I would much rather sell an aluminum headed engine, that starts an a nice clean aluminum casting, than reman anything. If we added a roller, iron headed engine, right in between the current 408's it would make the aluminum headed engine even more of a "no brainer" as the cost separation would be even less between the two. I know we mopar guys dont have a ton of choices out there, but at the same time we need to know a good value add when we see it too. I wouldn't intentionally put an iron head on anything at this point in the game. And since we are so far removed from a reman company, the cost savings vs reward just isnt there.
If you have never had a roller cam, it's one of those "will never go back" type upgrades. That new BPC4085CTCD engine is such a screamer compared to the LA engine it replaced.
I will gladly help ya with a little when the time comes to order on the aluminum headed engine. As far as the head castings and such. We buy the aluminum ones from edelbrock bare, and we then clean them up and assemble them in Nebraska our way, with our valves and contents. The iron ones, I will honestly have to look and see if those are OE castings or aftermarket. The iron headed engine is not a super popular engine, and i didnt help design it, so i dont have it memorized like i do my bpc4085.

I'm just on my phone right now, and will hop back on to read all the questions on PC in a bit.

Thanks for the callout and interest

What all do you guys do to the bare Edelbrock heads?
 
What all do you guys do to the bare Edelbrock heads?
Firstly, you wouldn't believe how filthy some aftermarket heads are out of the box. So they are hand cleaned. Burrs and flaws addressed. From there, pretty basic cleanup, valve job, and assembly using our components. Those components are QC'd by us. And IMO better.

Since the above is kinda "sales BS-Ish" to get to brass tacks, No they arent cnc'd, or fully ported, that's labor intensive and at this HP and rpm range, the HP per dollar isnt there.

Even on our big block 632 engines, the cost added to take them from 815 street HP to 840 is worth it to a drag racer...but not the average street customer.

I will fully confirm that they are however 1000% better than buying a set out of the box as far as quality, cleanliness, and longevity goes.
 
Firstly, you wouldn't believe how filthy some aftermarket heads are out of the box. So they are hand cleaned. Burrs and flaws addressed. From there, pretty basic cleanup, valve job, and assembly using our components. Those components are QC'd by us. And IMO better.

Since the above is kinda "sales BS-Ish" to get to brass tacks, No they arent cnc'd, or fully ported, that's labor intensive and at this HP and rpm range, the HP per dollar isnt there.

Even on our big block 632 engines, the cost added to take them from 815 street HP to 840 is worth it to a drag racer...but not the average street customer.

I will fully confirm that they are however 1000% better than buying a set out of the box as far as quality, cleanliness, and longevity goes.

Any thought of selling the prepped heads? They'd probably be decent sellers given Edelbrock's record for QC lately (as you noted).
 
Cool. Thanks Johnny! Yes, the $1,300 current price difference between the iron head flat tappet 408 and the aluminum head roller 408 is a screaming deal. No argument there. Telling myself to suck it up and clip coupons!

Hypothetically... if several of us wanted to buy one at the same time would BluePrint do a volume discount deal?
Honestly the "group buys" never go anywhere.
Unless someone wants 5, all paid for by a single check or wire, assuming it's all unique shipping address's, ya'll are just better off giving me a holler 1 on 1. Like I said, happy to help anyone, anytime.
 
Any thought of selling the prepped heads? They'd probably be decent sellers given Edelbrock's record for QC lately (as you noted).
It's been discused. I pushed hard for our own casting. It's all about volume. Always the catch 22 of sales volume increasing on what you currently have, to show where future endeavors are profitable enough to explore. Need everyone's help blowing the roof off the current offerings so we can do more in the future. Tall task. As you see above...everyone wants exactly what you have, except completely different ;)
 
Yeah, I bet that's common! Actually, I do want exactly what you have, full stop. You've done the homework and made a killer package. Just saving up now.

I work in the auto supplier industry as an engineer. That's exactly what we live every day: you need volume to get the price down, but you need a lower price to get the volume!
 
Yeah, I bet that's common! Actually, I do want exactly what you have, full stop. You've done the homework and made a killer package. Just saving up now.

I work in the auto supplier industry as an engineer. That's exactly what we live every day: you need volume to get the price down, but you need a lower price to get the volume!
Sounds good to me! Looking forward to helping out.
 
So I just confirmed with ATK: they DO NOT use the EQ (Engine Quest) heads on their iron head 360 crate motors! Stock Magnum heads. Very disappointing. Those stock Magnum heads are extremely crack prone. Why you would use those to save a couple bucks is beyond me. I asked them to consider using the EQ's and charging a bit more. We'll see if I get any response.

Given that, I'd have to scratch ATK from the list. So, my crate engine short list is even shorter now:

No #1 - For sure the BluePrint Engines 408 (BPC4085CTC): 465hp / 494 tq / Alum head / roller cam / $7,300 complete (without damper and water pump) or $7,800 (w/ damper, water pump, air cleaner, plug wires). This is top shelf in my mind, but a little pricey.

No #2 - Same as above but iron heads and flat tappet (BPC4082CTC) : 375hp / 460tq. Saves about $1,300. I assume they use the EQ heads, but need confirmation from BluePrint. If they are stock Magnum heads, then this would have to get scratched from the list too.

No #3 - PIE (Performance Injection Equipment) 360 : 450hp / 465tq / EQ modified iron heads / roller cam / $6,350 complete incl. damper and water pump (but minus carb). CONFIRMED they use the EQ heads, then they modify them from there with mild porting, manganese valve guides and 2.02 intake valves. They do make this as a 408 for $650 more, but then you're getting really close to the BluePrint.

After much research, this is my short list. If anyone knows of a good low-cost EQ-based iron head roller 360, I'd be all ears to add it to the list, but I haven't found it. Thanks all for the good discussion and help.
 
So I just confirmed with ATK: they DO NOT use the EQ (Engine Quest) heads on their iron head 360 crate motors! Stock Magnum heads. Very disappointing. Those stock Magnum heads are extremely crack prone. Why you would use those to save a couple bucks is beyond me. I asked them to consider using the EQ's and charging a bit more. We'll see if I get any response.

Given that, I'd have to scratch ATK from the list. So, my crate engine short list is even shorter now:

No #1 - For sure the BluePrint Engines 408 (BPC4085CTC): 465hp / 494 tq / Alum head / roller cam / $7,300 complete (without damper and water pump) or $7,800 (w/ damper, water pump, air cleaner, plug wires). This is top shelf in my mind, but a little pricey.

No #2 - Same as above but iron heads and flat tappet (BPC4082CTC) : 375hp / 460tq. Saves about $1,300. I assume they use the EQ heads, but need confirmation from BluePrint. If they are stock Magnum heads, then this would have to get scratched from the list too.

No #3 - PIE (Performance Injection Equipment) 360 : 450hp / 465tq / EQ modified iron heads / roller cam / $6,350 complete incl. damper and water pump (but minus carb). CONFIRMED they use the EQ heads, then they modify them from there with mild porting, manganese valve guides and 2.02 intake valves. They do make this as a 408 for $650 more, but then you're getting really close to the BluePrint.

After much research, this is my short list. If anyone knows of a good low-cost EQ-based iron head roller 360, I'd be all ears to add it to the list, but I haven't found it. Thanks all for the good discussion and help.

The iron head blue print uses oem magnum heads as well, or at least they did in the past. PM Johnny he is a good guy and will help you out.
 
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So I just confirmed with ATK: they DO NOT use the EQ (Engine Quest) heads on their iron head 360 crate motors! Stock Magnum heads. Very disappointing. Those stock Magnum heads are extremely crack prone. Why you would use those to save a couple bucks is beyond me. I asked them to consider using the EQ's and charging a bit more. We'll see if I get any response.

Given that, I'd have to scratch ATK from the list. So, my crate engine short list is even shorter now:

No #1 - For sure the BluePrint Engines 408 (BPC4085CTC): 465hp / 494 tq / Alum head / roller cam / $7,300 complete (without damper and water pump) or $7,800 (w/ damper, water pump, air cleaner, plug wires). This is top shelf in my mind, but a little pricey.

No #2 - Same as above but iron heads and flat tappet (BPC4082CTC) : 375hp / 460tq. Saves about $1,300. I assume they use the EQ heads, but need confirmation from BluePrint. If they are stock Magnum heads, then this would have to get scratched from the list too.

No #3 - PIE (Performance Injection Equipment) 360 : 450hp / 465tq / EQ modified iron heads / roller cam / $6,350 complete incl. damper and water pump (but minus carb). CONFIRMED they use the EQ heads, then they modify them from there with mild porting, manganese valve guides and 2.02 intake valves. They do make this as a 408 for $650 more, but then you're getting really close to the BluePrint.

After much research, this is my short list. If anyone knows of a good low-cost EQ-based iron head roller 360, I'd be all ears to add it to the list, but I haven't found it. Thanks all for the good discussion and help.

BPC4085CTC DOES come with a damper installed. the picture just needs updated. So maybe consider that $120 "to the good" if you were buying a damper elsewhere.

The iron headed engines do use an OEM 671 or 302 casting. If the belief is that despite our hand assembly, inspection, and QC process's is that any OE magnum head isn't for you, then this one isn't on your list.

I'd rebuttal with the fact we produce and dyno 50 engines a day here. If cracking magnum heads was on our repeat warranty reports, we wouldn't be using them. (do we find them and scrap bad castings in QC BEFORE any assembly, YES!)

considering the damper clarification, With only an approx $1500 difference from an iron headed flat tappet engine, and an aluminum headed, roller cam engine, I can't see offering one somewhere in the middle where an assembled iron head from a third party would require as much QC and Labor as our aluminum ones do.

Its easy for me to spend someone else money, I get that. But the retail value on a set of edelbrock, assembled, magnum heads is $999 EACH. considering we add those AND a roller cam/valvetrain to the bpc4085, vs the bpc4082... makes "pricey" a very, very, relative term, for only the $1500-1600 difference.

just my 2 cents here. Hopefully one of our options ends up being what you're looking for. As always. happy to help anytime.
 
Johnny - OK, great. Thanks for the clarification on the damper. Yes, that is a plus in the value equation (which should be in the picture as you mentioned). And perhaps "pricey" was the wrong word. I think it's an unbelievable value and well worth the money, I only meant that in absolute terms $7,800 is a decent chunk out of the bank account (pricey in total cost, not relative value). But for what you get it looks impossible to duplicate anywhere else. Amazing overall package.

As for the OE iron Magnum heads, it's not that they are cracked when you build them or that they crack on the dyno or any time in your possession. I know you guys would never build or ship anything in that condition. But over time they have a very high propensity to crack (and maybe after the warranty period). If I'm spending crate engine money, I don't want to take a chance on such a head.

Neither here nor there, the 4085CTC is the clear winner in my book. Just need to save up for an extra year or raid the kids college fund...
 
Johnny - OK, great. Thanks for the clarification on the damper. Yes, that is a plus in the value equation (which should be in the picture as you mentioned). And perhaps "pricey" was the wrong word. I think it's an unbelievable value and well worth the money, I only meant that in absolute terms $7,800 is a decent chunk out of the bank account (pricey in total cost, not relative value). But for what you get it looks impossible to duplicate anywhere else. Amazing overall package.

As for the OE iron Magnum heads, it's not that they are cracked when you build them or that they crack on the dyno or any time in your possession. I know you guys would never build or ship anything in that condition. But over time they have a very high propensity to crack (and maybe after the warranty period). If I'm spending crate engine money, I don't want to take a chance on such a head.

Neither here nor there, the 4085CTC is the clear winner in my book. Just need to save up for an extra year or raid the kids college fund...
Yup understood entirely, and I feel you have the correct take away for sure. You're right, its a chunk of change by any comparison, and is worth asking questions and doing research for sure!
 
The OE Magnum head crack issue is over rated in the sense that it will be an issue to a running driving vehicle. Of course you would never use a cracked head to rebuild and use in your car, but, if you own a Magnum engine and the heads are cracked, you would never know.

If you build your own Magnum engine, as far as I’m concerned, the only head material to use is aluminum. Edelbrock’s for low to mid level performance and then the Trick Flows for mid to high power levels.

You could use a MoPar W head and pushrod oil the valve train, but unless your building a balls to the wall engine, I would not bother with a W series head unless you already have it. The head itself (W-2/5) isn’t that expensive anymore, just a bit pricey on rocker gear. (Stepping up and above a Harland Sharp set up.)
 
@rumblefish360 - Yes, to your point a cracked Magnum head can run a pretty long time without even being able to tell (and may take a while to even crack in the first place). But over time that crack gets worse (i.e. coolant starts to leak in, etc). The head replacement rate in the field on 318 / 360 Magnums is quite high. There's a reason there are 3-4 companies making regular replacement heads for them. The point is, why would you buy a crate motor with crack-prone heads, even if it would take ~30-60k miles to manifest itself? Or even if there's "only" a 25% chance it happens? It's too much money to risk it.

I agree with you: aluminum all the way! Just save up and do it right.
 
Thought it was a dry crack on the magnum heads when they crack. Thought the fix was to put harden seats in the head.
 
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