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engine plans #3279769
01/01/25 05:43 PM
01/01/25 05:43 PM
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cha1lenger Offline OP
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I have experience racing big block and small block mopar, but my next endeavor is exploring the Gen 3 hemi. I have nearly no experience with this platform. I love that the BGE block is so strong, to get a race block for B/RB or SB is soooo cost prohibitive.

My goals:
650+ horsepower naturally aspirated and bulletproof reliability for bracket racing
7000 RPM, maybe 7500 max? I don't want to make valvetrain a reliability concern

Tentatively figuring on BGE block, 426 stroker kit, AFR heads?, drag pak intake.

I am unsure on the heads, if an aftermarket head is money well spent. I am unsure on the valvetrain, I can't believe what Jesel or T&D ask for rocker arms. I am also tentatively leaning toward carburetor but could be swayed either way. Also, not sure if someone has experience with a cam choice for this target.

Essentially, I am looking for advice on what pieces it will take to get to my goals. I don't want to cheap out, but like anybody I want to maximize bang for the buck.

Last edited by cha1lenger; 01/01/25 05:49 PM.
Re: engine plans [Re: cha1lenger] #3279826
01/01/25 08:51 PM
01/01/25 08:51 PM
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HotRodDave Online content
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Originally Posted by cha1lenger
I have experience racing big block and small block mopar, but my next endeavor is exploring the Gen 3 hemi. I have nearly no experience with this platform. I love that the BGE block is so strong, to get a race block for B/RB or SB is soooo cost prohibitive.

My goals:
650+ horsepower naturally aspirated and bulletproof reliability for bracket racing
7000 RPM, maybe 7500 max? I don't want to make valvetrain a reliability concern

Tentatively figuring on BGE block, 426 stroker kit, AFR heads?, drag pak intake.

I am unsure on the heads, if an aftermarket head is money well spent. I am unsure on the valvetrain, I can't believe what Jesel or T&D ask for rocker arms. I am also tentatively leaning toward carburetor but could be swayed either way. Also, not sure if someone has experience with a cam choice for this target.

Essentially, I am looking for advice on what pieces it will take to get to my goals. I don't want to cheap out, but like anybody I want to maximize bang for the buck.



At only 650 HP you don't even need to port the 6.4 heads, they flow similar to a fully ported W2 SB head. A fully ported 6.4 or BGE head can work to 800hp probably more in the right hands. Aftermarket heads are a huge waste of money on a 650HP 426. I would stick to the 426CID because the longer stroke requires such a short piston, keeping some amount of piston height is good for longevity. The stock rockers and even the factory hydraulic lifters are fine at 7000 or even 7500RPM. I wouldn't consider any other intake for carb or EFI if I could make room for a drag pack. Buying a BGE long block from a JY is like buying a R3 block, Indy 360 heads, good ductile iron non adjustable W2 rockers and a crank you can sell for $600, a $200 cam, a set of pistons you can get a couple hundred out of and if it has an intake you can make another $400 on it.


I am not causing global warming, I am just trying to hold off a impending Ice Age!



Re: engine plans [Re: HotRodDave] #3279931
01/02/25 11:31 AM
01/02/25 11:31 AM
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cha1lenger Offline OP
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Originally Posted by HotRodDave
At only 650 HP you don't even need to port the 6.4 heads, they flow similar to a fully ported W2 SB head. A fully ported 6.4 or BGE head can work to 800hp probably more in the right hands. Aftermarket heads are a huge waste of money on a 650HP 426. I would stick to the 426CID because the longer stroke requires such a short piston, keeping some amount of piston height is good for longevity. The stock rockers and even the factory hydraulic lifters are fine at 7000 or even 7500RPM. I wouldn't consider any other intake for carb or EFI if I could make room for a drag pack. Buying a BGE long block from a JY is like buying a R3 block, Indy 360 heads, good ductile iron non adjustable W2 rockers and a crank you can sell for $600, a $200 cam, a set of pistons you can get a couple hundred out of and if it has an intake you can make another $400 on it.


Thanks for the reply!!

Follow up question, what would it take N/A to get more horsepower? 650 was just a number I pulled from nowhere. I agree with you I don't want to stroke past 426 even though it would be tempting.

And 6.4 in junkyard seems like nearly impossible to find for under $5k. Considering I wouldn't use the rotating assembly, it seems like the math makes sense to buy a new block and start from scratch. And I was looking at porting stock heads, by the time you buy them and send them for porting it seems to start adding up fast in cost. I certainly hadn't considered what it would 'earn' to sell off the pieces that aren't re-used.

Re: engine plans [Re: cha1lenger] #3279942
01/02/25 11:52 AM
01/02/25 11:52 AM
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RTSE4ME Offline
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Finding a JY engine is the way to go unless you have all the small parts laying around.
Once you get passed around 650 HP on a n/a GEN3 prices get stupid better off with boost. I think there some decent turbo headers available now at reasonable prices.
I bought complete jJY BGE engine last year for under a grand too bad it hurt the block.

Re: engine plans [Re: cha1lenger] #3279953
01/02/25 12:33 PM
01/02/25 12:33 PM
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Tulsa OK
Bad340fish Offline
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Originally Posted by cha1lenger
Originally Posted by HotRodDave
At only 650 HP you don't even need to port the 6.4 heads, they flow similar to a fully ported W2 SB head. A fully ported 6.4 or BGE head can work to 800hp probably more in the right hands. Aftermarket heads are a huge waste of money on a 650HP 426. I would stick to the 426CID because the longer stroke requires such a short piston, keeping some amount of piston height is good for longevity. The stock rockers and even the factory hydraulic lifters are fine at 7000 or even 7500RPM. I wouldn't consider any other intake for carb or EFI if I could make room for a drag pack. Buying a BGE long block from a JY is like buying a R3 block, Indy 360 heads, good ductile iron non adjustable W2 rockers and a crank you can sell for $600, a $200 cam, a set of pistons you can get a couple hundred out of and if it has an intake you can make another $400 on it.


Thanks for the reply!!

Follow up question, what would it take N/A to get more horsepower? 650 was just a number I pulled from nowhere. I agree with you I don't want to stroke past 426 even though it would be tempting.

And 6.4 in junkyard seems like nearly impossible to find for under $5k. Considering I wouldn't use the rotating assembly, it seems like the math makes sense to buy a new block and start from scratch. And I was looking at porting stock heads, by the time you buy them and send them for porting it seems to start adding up fast in cost. I certainly hadn't considered what it would 'earn' to sell off the pieces that aren't re-used.


If you happen to find one I am in the market for a good 6.4 crank. I bought a cheap 6.4 off of eBay that I knew might need a crank and it turns out it does. I am in zero rush.

I had the same thoughts as you on building from new but with a junkyard engine you get all those little parts and nuts and bolts that add up really fast when it comes to replacement. I paid a low enough price that if nothing below the heads turns out usable I still did OK just not great.


68 Barracuda Formula S 340
Re: engine plans [Re: RTSE4ME] #3279961
01/02/25 12:48 PM
01/02/25 12:48 PM
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cha1lenger Offline OP
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Originally Posted by RTSE4ME
Finding a JY engine is the way to go unless you have all the small parts laying around.
Once you get passed around 650 HP on a n/a GEN3 prices get stupid better off with boost. I think there some decent turbo headers available now at reasonable prices.
I bought complete jJY BGE engine last year for under a grand too bad it hurt the block.


Can I ask how you found the engine? I am having like zero luck.

Re: engine plans [Re: cha1lenger] #3279994
01/02/25 02:56 PM
01/02/25 02:56 PM
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RTSE4ME Offline
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Facebook MP, it was cheap enough to take a chance. Only reason I bought it like most junk on Facebook.
I sold the cam , exhaust manifolds and other bits off it to get my money back. Still have block,crank & heads.
This was my 4th Gen3 engine I have bought... locked up. First 6.4 though.

Re: engine plans [Re: RTSE4ME] #3280039
01/02/25 06:03 PM
01/02/25 06:03 PM
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Pattison Texas
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a new BGE block is only 2k


1968 Charger COLD A/C Hilborn EFI
512ci 9.7 compression, Stealth heads, 4.10 gear A518 ODtrans 4100lb,10.93 full street car trim
2020 T/A 392 Stock 11.79 @ 114.5

Re: engine plans [Re: CSK] #3280046
01/02/25 06:24 PM
01/02/25 06:24 PM
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A stock SRT 392 will spin over 500 on an engine dyno, so just go from there. If built to RPM you may not need to go all the way to 426 for another 150hp

Re: engine plans [Re: Bad340fish] #3280097
01/02/25 10:34 PM
01/02/25 10:34 PM
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Kalispell Mt.
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Originally Posted by Bad340fish
Originally Posted by cha1lenger
Originally Posted by HotRodDave
At only 650 HP you don't even need to port the 6.4 heads, they flow similar to a fully ported W2 SB head. A fully ported 6.4 or BGE head can work to 800hp probably more in the right hands. Aftermarket heads are a huge waste of money on a 650HP 426. I would stick to the 426CID because the longer stroke requires such a short piston, keeping some amount of piston height is good for longevity. The stock rockers and even the factory hydraulic lifters are fine at 7000 or even 7500RPM. I wouldn't consider any other intake for carb or EFI if I could make room for a drag pack. Buying a BGE long block from a JY is like buying a R3 block, Indy 360 heads, good ductile iron non adjustable W2 rockers and a crank you can sell for $600, a $200 cam, a set of pistons you can get a couple hundred out of and if it has an intake you can make another $400 on it.


Thanks for the reply!!

Follow up question, what would it take N/A to get more horsepower? 650 was just a number I pulled from nowhere. I agree with you I don't want to stroke past 426 even though it would be tempting.

And 6.4 in junkyard seems like nearly impossible to find for under $5k. Considering I wouldn't use the rotating assembly, it seems like the math makes sense to buy a new block and start from scratch. And I was looking at porting stock heads, by the time you buy them and send them for porting it seems to start adding up fast in cost. I certainly hadn't considered what it would 'earn' to sell off the pieces that aren't re-used.


If you happen to find one I am in the market for a good 6.4 crank. I bought a cheap 6.4 off of eBay that I knew might need a crank and it turns out it does. I am in zero rush.

I had the same thoughts as you on building from new but with a junkyard engine you get all those little parts and nuts and bolts that add up really fast when it comes to replacement. I paid a low enough price that if nothing below the heads turns out usable I still did OK just not great.



I have one from a 2022 6.4 that was in a fire, I bought in 2023 so almost no miles. I also have another that needs turned down. Where are you located?


I am not causing global warming, I am just trying to hold off a impending Ice Age!



Re: engine plans [Re: HotRodDave] #3280178
01/03/25 11:26 AM
01/03/25 11:26 AM
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Tulsa OK
Bad340fish Offline
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Originally Posted by HotRodDave



I have one from a 2022 6.4 that was in a fire, I bought in 2023 so almost no miles. I also have another that needs turned down. Where are you located?


I am in Tulsa Oklahoma


68 Barracuda Formula S 340
Re: engine plans [Re: Bad340fish] #3280240
01/03/25 02:29 PM
01/03/25 02:29 PM
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With a stroker 6.4, 650 HP should be easy peasy with stock heads and the right cam and compression.

A JY is going to want a premium for any 6.4, but there are deals out there.

I gave $2400 for the following package deal from a guy's abandoned project -

*Stock bore BGE 6.4 complete short block (supposedly 18K miles from a cab fire in a service truck and the block sure looked low mileage)
*Stock BGE complete heads w/rockers
*SRT front cover
*Manley 4.08 crank
*Manley Rods
*Billet main caps
*ATI balancer

The stroker stuff was originally used in a 6.1 block, so I would have had to buy mix/match new rods/pistons and deal with the crank snout/front cover situation AND this 6.4 block was one of the blocks with the "short" cylinders that are difficult to put a stroker crank in.

I sold all of the used stroker stuff for $1600 and that paid for machine work (hone and balance), NEW replacement SRT 6.4 pistons/rods, head work, rod and main bearings, and all new bolts. Polished the OE 6.4 crank (forged) and the short block is done.

$$$$....

$2400 short block and head work
$150 oil pump
$400 ATI balancer
$400 head work
$480 cam
$500 lifters
$180 pushrods
$350 springs/retainers/locks
$350 oil pan and pick up
$650 carb intake (OUCH)
$350 gaskets

Less than $6500 intake to pan, not including the cheesy valve covers. (Stock VC's would work just fine) CR is a measured/calculated 10.93:1. Heads FLOW! Fresh VJ on the BGE heads, showed us 336 cfm @ .600" Then 6 hours ($400) worth of massaging by my cylinder head guy got us 362/248 cfm @ .600"

Will it make 700 HP? No way. 650? Nope, but should be north of 600 on pump gas.

So yea, as HRDave said, I have the equivalent to a 392 small block, R3 Block, ported Indy heads, and Indy intake...LOL Fun fact: On the flow bench that Prefix intake was a ZERO loss when bolted to the head.

hemi.jpg
Last edited by cudadoug; 01/03/25 04:27 PM.
Re: engine plans [Re: cha1lenger] #3280269
01/03/25 04:44 PM
01/03/25 04:44 PM
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Tay Offline
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426ci/650HP , is not hard with a G3 , Hell ,depending on the engine management system , Blueprint crate 426 makes a legit 610hp/520Tq with a crappy rip off job of Holley’s old G3 Sniper intake , 90mm Throttle body ,Stock Apache heads 2.14X8mm 1.645X8mm valves …. Cam they come with is 614/.614 lift ,230/255@ .050 115 LSA cam and 10.40 to 1 compression, on good 93oct and some creative timing, it’ll make as much as 625/540.
We’ve run them with a bench mount Ram1500 2014 PCM, hit 615hp and called it a day. With a Holley Terminator system 620 is not out of the question, just plug and go.
We had one (BluePrint426) on the dyno new year’s day made 650@ 6500, 585 @5600 with a Drag pak Intake , out of the box Holley Ulitmit XP 950 carb and MSD Hemi-6, same engine with Comp Cams 201-337-17 .635/.635 229/241 @ .050 117LSA made 675hp @ 6800 &610Tq @ 5800.
Hughes Engines did 720HP (then re-did the dyno sheet to say 740) back in late 2016 maybe 17 , with a 6.1 based 426 (4.08X4.08) If I remember they claimed Compression was 13.1 to 1 They used the pre Eagle head with 2.10 and 1.625 valves, heads were flowing 330@ 650 lift Intake was a Ritter drag pak copy, carb was a 950 Holley, MSD hemi 6 box, cam was .640/.640 250/255 @/050 110 lsa, Peak HP was 7100-7500. Depending on which copy of the dyno sheet was posted, I’ve seen that “package” done a few times, and 700hp with 12 to 1 is attainable and more along what I’ve done and have seen.
I’ve built that “Hughes combo” 6 times with 6.1 blocks, all ranging between 421 and 428ci, once was 4.055X 4.08 (421CI) with a set of Pre Eagle heads done by Performance Injection out of Delaware, intake manifold started out as a pair of R5P7 Mopar that were cut up, welded ,mangled, re-welded, re-mangled, 950 Holley, compression was 11.8 to 1 ,Cam was Howards 786965-13 .625/.600 237/237 @ .050 113 lsa , made 680ishHP @ 7000 ,620ish Tq at 5800 on 93 oct, at the track in a 71 duster, 3k race weight , ran 9.80s 138-145mph at Atco(RIP Atco) 3 of the other builds were with Eagle heads, 2.125/1.625 valves , same Howards 786965-13 cam, roughly 690/700 ish hp, same TQ results, the other 2 versions of this combo were with MMX ported Apache/BGE heads , one was 4.08X4.08(426) the other was 4.075X 4.05(422) roughly 700ish HP, but both of these made peak Tq above 6k.
I like Eagle heads Vs Apache/BGE heads for the street type builds, the smaller Exhaust valve keeps TQ peak lower and seems to carry the TQ band 500RPMs longer.
AFR and the New BlackBird heads , those are for those who have money to spend on special lifters/ custom cams and 4k+ rocker gear, let’s face it , What good are heads that flow over 400cfm @ 700lift if the biggest practical cam you can buy is .640(+/- .010) the OEM style lifter and cam core limits the G3 to about .660 lift, besides most people don’t spin these G3s high enough to utilize the 375CFM that the average port job on an Apache/BGE yields.
Stock rockers will spin to 8k with some prep work, Lash caps are your HIGH rpm friend MAKE sure the Ends of the rocker are even , no casting high spots , Banana grove the shafts, the top side of the shaft has 2 oling holes, one for “rest” the other for “max Lift” issue is the Max lift hole gets blocked once you go over .550(gross) lift, hence the reason a lot of people complain about burnt tips. The bottom side of the shaft has one hole which is a constant feed. Rocker shafts hold downs like the ones Stanke sells, are a preference thing, I spin my 380CI G3 to mid 7kRPMs with stock oem hold downs,(and stock oil pump) but…I do have rocker shaft collars to keep the rockers from shifting back and forth.
Lifter Trays, AAD performance has a Billet Aluminum one that is worth the $220(as of this posting) , it’s great piece of mind ,nothing says Crap like one of the OEM plastic lifter trays cracking…Granted , it’s rarity for those OEM trays to break but they do.
Best option, find a 392SRT or 6.4l truck engine, either buy a stroker kit, or DIY a kit. Eagle, Manley, Scat, Molnar, K1 all have 4.05 cranks, doesn’t matter which one you buy, they’ll all take a 700HP beating. Rods that’s your choice. DSS pistons are worth looking into, good price, part# 1-6817-4090 is a +4 dome STD bore 1.12 pin height, it’s for a 4.05 crank with 6.125 Rods, with Apache/BGE head this piston is 12.1 to 1, I’m building a 427(4.10X4.05) next week with this piston DSS piston,
One of great things about the G3 is ,you can run as high as 12 to 1 on the street with 93oct. with aftermarket pistons.
Next best deal is a OEM 392, there are a lot of builds out there with “drop in forge piston and rods” 600 street able HP” the stock 392 crank is good for 750-800hp and mid 7k rpms , they don’t start to “jump rope” till high 7k.
Intake , For EFI the Edelbrock Victor will get you to 7kRPMs , but that’s about it’s high point, the OEM intakes are good for mid 6kRPMs,
Holley HI-Ram is best all purpose option, Go EFI, use one top, Change over to Carb, go buy a different top, in a carb application, the Dual 4150 top is max effort , and fueling is very even.
All out Carb, the Drag pak is within a few HP of the twin 4150 top HI Ram…for single carb , Drag pak is the best option…. if you don’t mind the Carb sticking through the hood, Ritter single plane has some fueling issues, mostly 5/7 passage, but fixable, it will not out power the Drag pak, Prefix has a good carb Intake , broad Tq ,works well between mid 4k to 7k RPM, I like to think of it as the old B/RB Holley street dominator intake.

Holley Single plane.......For Carb...LOL , it's a Joke it's only value is for those who don't want to cut a hole in their hood.....For EFI , it's actually not bad, More for the Stocker types who want more power above 6k but don't want to buy a Prefix or Drag pak.

The Odd ball intake, Indy Mod man, not bad for EFI, not going to set any track records either, Last but not least in the carb application is OCperformance Dual plane, Think of it as the Performer RPM for the G3.

Last edited by Tay; 01/03/25 04:56 PM.
Re: engine plans [Re: cudadoug] #3280273
01/03/25 04:58 PM
01/03/25 04:58 PM
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Quakertown PA
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Tay Offline
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Originally Posted by cudadoug
With a stroker 6.4, 650 HP should be easy peasy with stock heads and the right cam and compression.

A JY is going to want a premium for any 6.4, but there are deals out there.

I gave $2400 for the following package deal from a guy's abandoned project -

*Stock bore BGE 6.4 complete short block (supposedly 18K miles from a cab fire in a service truck and the block sure looked low mileage)
*Stock BGE complete heads w/rockers
*SRT front cover
*Manley 4.08 crank
*Manley Rods
*Billet main caps
*ATI balancer

The stroker stuff was originally used in a 6.1 block, so I would have had to buy mix/match new rods/pistons and deal with the crank snout/front cover situation AND this 6.4 block was one of the blocks with the "short" cylinders that are difficult to put a stroker crank in.

I sold all of the used stroker stuff for $1600 and that paid for machine work (hone and balance), NEW replacement SRT 6.4 pistons/rods, head work, rod and main bearings, and all new bolts. Polished the OE 6.4 crank (forged) and the short block is done.

$$$$....

$2400 short block and head work
$150 oil pump
$400 ATI balancer
$400 head work
$480 cam
$500 lifters
$180 pushrods
$350 springs/retainers/locks
$350 oil pan and pick up
$650 carb intake (OUCH)
$350 gaskets

Less than $6500 intake to pan, not including the cheesy valve covers. (Stock VC's would work just fine) CR is a measured/calculated 10.93:1. Heads FLOW! Fresh VJ on the BGE heads, showed us 336 cfm @ .600" Then 6 hours ($400) worth of massaging by my cylinder head guy got us 362/248 cfm @ .600"

Will it make 700 HP? No way. 650? Nope, but should be north of 600 on pump gas.

So yea, as HRDave said, I have the equivalent to a 392 small block, R3 Block, ported Indy heads, and Indy intake...LOL Fun fact: On the flow bench that Prefix intake was a ZERO loss when bolted to the head.


Hey I like those cheesy Valve cover.

Prefix's intake was designed for CASCAR, lots of R&D went in to it......it realy is the best all round/multy purpose intake, both EFI and Carb.

Re: engine plans [Re: Tay] #3280293
01/03/25 06:47 PM
01/03/25 06:47 PM
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cudadoug Offline
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[
[/quote]

Hey I like those cheesy Valve cover.

Prefix's intake was designed for CASCAR, lots of R&D went in to it......it realy is the best all round/multy purpose intake, both EFI and Carb. [/quote]

Lol... they are better than the FUGLY OE covers. At $399, a better option (for me) than the $1000-up billet covers, or even the sheet metal versions.

Yes, I learned about that Prefix intake several years ago. Once we had it in our hands and on the flow bench, wow! Plus...I don't have the hood clearance for a DP intake







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