Gen II 426 hemi v. gen III

[70chall440]

This post is what could be termed "thinking out loud" so please bear with me. 

I have a 1966 426 Hemi which like many was used as a race motor. It was "windowed" and repaired at some point in its life but has been sonic checked and is good. I have had all of the machine work done and the short block as well as the heads have been rebuilt. The only issue with is that the rear main cap which takes the oil intake tube is damaged slightly, so I will run an external Mildon oil system. The engine currently has like 13.1 pistons in it which will require me to run .090 - .100 thick head gaskets to get the CR down to something reasonable or change pistons.

This engine was/is intended for my 70 Roadrunner with the plan to install EFI on it as my Roadrunner is pretty modified complete with a tilt front end and a Charger like quarter panel gas filler. Regardless, as I am thinking about this I am beginning to lean towards selling off the 426 and installing a Gen III hemi instead. Either way it will be a stick car as I have to have a pistol grip  , that with the air grabber makes the car for me. A bigger point is that I have enough garage art and would like it to be reliable and drivable when done (whenever that may be).

I have been mulling this over for a long time and I am a long time before I need to decide as I am still trying to get my 73 Cuda done. However, this deal keeps popping into my mind. I just thought I would put it out there and see what others think.

So, the question is do I stay old school (to a degree) or do I go new school? On the one hand, it would be a good fit sitting with my 440 6 pack (efi) Challenger RT and 340 (stroked and EFI 6 pack) Cuda, but on the other it would be nice to know it will start/run and be pretty reliable. Yes, I am sure I can make it "reasonably" reliable but lets be honest, the new power plants are considerably more efficient. that said, they surely do not have the "wow" factor that the old school does which I guess is what is driving this dilemma.

thoughts and opinions welcome I would just ask that they be reasonable and relevant.

[onebadfish]

If it were me, I would stick to the Gen 2. Just something about running an old school hemi in something like a modified 70 Runner. I think it can be built to be reliable with EFI and you will be totally satisfied. I like the way a gen 2 hemi sounds opposed to the modern engine. I would change the pistons as thick head gaskets tend to leak - at least I always had problems with them on forced induction stuff.

[70chall440]

Appreciate your response and I agree with you. After thinking about it, I have a Gen I and several Gen III hemi's, makes sense to have the Gen II as well, plus nothing looks as good. 

[73440]

I don't have anything against seeing a Gen III in an early car , but always am glad to see an original type engine when that hood opens.

[70chall440]

Yea thats basically where I arrived at, opening the hood and seeing that elephant is awesome. It will be even better with the tilt front end ad big chrome headers.

[1 Wild R/T]

I've got a buddy with a 61 Falcon set up as a gasser, flip front, straight axle.... Kinda cool if your into gassers, but he choose to run a 5.0 Coyote.... Kills the look IMO, it's a confused vehicle.. Total old school look and super modern engine... Bad choice IMO... He should have either done a FE or a small block....

And you should stick with your Gen II which it sounds like what you've already realized anyway....

[70chall440]

Good points and I agree, Plus a 5.7 or 6.1 just isnt going to look near as cool  426 it is 

[1 Wild R/T]

So the next question is how to lower the compression... Spacers or thick head gaskets are going to make sealing the intake a nightmare... Even with all the normal parts Hemi's have sealing issues.... I'd take a hard look at machining the domes, My old 12.5 Hemi pistons had enough meat to cut them down into the 11-1 range... You might get lucky.... If not I'd dig deep & buy the right pistons...

When your ready to screw that hemi together if you haven't already talk to someone who's been there about sealing the heads & intake..... Also rocker geometry....  Not an engine for beginners... Not saying you are, I know you've played with a good bit of stuff but still Hemi's have their own challenges...

[70chall440]

So the next question is how to lower the compression... Spacers or thick head gaskets are going to make sealing the intake a nightmare... Even with all the normal parts Hemi's have sealing issues.... I'd take a hard look at machining the domes, My old 12.5 Hemi pistons had enough meat to cut them down into the 11-1 range... You might get lucky.... If not I'd dig deep & buy the right pistons...

When your ready to screw that hemi together if you haven't already talk to someone who's been there about sealing the heads & intake..... Also rocker geometry....  Not an engine for beginners... Not saying you are, I know you've played with a good bit of stuff but still Hemi's have their own challenges...

I thought about cutting the pistons down, and that might viable. If not (as you suggest) I will have to purchase some new pistons.

You are right, I have played with a lot of Mopars but not Hemi's so I will definitely need some advice/assistance. I realize they are not the same a normal wedge engines. Probably one of the reasons I haven't done more with it thus far. I have bought some books but to be honest I really need to find some resources locally to assist.

[Topcat]

Well I've been down this road as far as building a gen II Hemi.

If you want it to look just like it was supposed to be like in either 70' or 71',  it's big bucks.
then make it run even better and it adds up.

My engine is a stroked 71' cast block and OEM slight pocket ported heads.
Stroked with a 472 crank, EDM solid lifter, and all types of other goodies.

It took quite a long time to get it all correct.
These engines are like a nuance jig saw puzzle to get all the right pieces and everything working just right.

For example: You stroke it; the Carter's OEM settings won't be enough.
You better be a jet/needle expert if you go that route. 
Rabbit is out of the hat. Been there done that.

I probably have 30 grand into my Hemi. If not more.
But this is a factory close resto I did. You open the  hood, and it's 1971

You can build them cheaper but then they look cheaper. IMO.

Gen III is quick start ready to rock. Just not as pretty a girl whio is a little bit lower maintenance in the blankets.
And you won't have to date her as much till you get her.   

[jimynick]

Mike, I think that old gen 2 hemi is a piece of junk and you'd do well to be rid of it and in saying so, I'd be happy to help you in your quest to get rid of it! Definitely go gen 3 and get rid of all that old, carburated ****e. It'll be a royal PITA to mess with and I'll be happy to help ya out mate. Let me know, eh? 

[70chall440]

Topcat - greatly appreciate the input. I am not looking to make it look like a 70 or anything resembling a restoration, to that end I dont really care what it looks like as far as vintage. What I do care about is it being relatively reliable (not like daily driver reliable per se, just not something that is unmanageable). This is one of the reasons I fully intend to run EFI on it. I am also not looking for huge HP out of it, to be honest I am really looking for the "wow" factor more than trying to squeeze all of the HP I can get out of it. Perhaps better said, I need it to run when I go to start it and run relatively problem free or at least minimal. I already have a 70 Challenger with a 440 and EFI 6 pack, a 73 Cuda restomod with a stroked 340 and EFI 6 pack (not to mention plenty of modern cars to drive), so this is more of a "cool" car more than anything else. Therefore, I want it to run on pump gas.

I am sure some will think this is a waste of a good Hemi, but it is what it is. I already have far more money in my Cuda than I care to admit and not just a little bit in my Challenger, so my tolerance for spending thousands on a motor isn't very deep. Not to say that I am unwilling to get what I need to make the engine run, just that I don't intend to chase a plethora of high speed parts I don't really need.

[70chall440]

Mike, I think that old gen 2 hemi is a piece of junk and you'd do well to be rid of it and in saying so, I'd be happy to help you in your quest to get rid of it! Definitely go gen 3 and get rid of all that old, carburated ****e. It'll be a royal PITA to mess with and I'll be happy to help ya out mate. Let me know, eh? 

Jimy - thats mighty nice of you..  Seriously though, this is kind of what made me post this is the first place. A Gen III would in fact be far more reliable, however as stated would not have the overall effect that the Gen II does and more to the point; if I were to dump this 426 I would never have one again most likely and what type of Mopar guy would I be then... Same reason I bought my Viper, I felt I needed that as a real Mopar guy... LOL. Of course I tried to use the same rationale with my wife to get a Hellcat but she wasn't having it since there is a 2010 RT in the shop already..

To me, a 70 RR with a 426, air grabber and 4 spd is pretty much the top of the game for breed (winged cars excluded).

[jimynick]

"To me, a 70 RR with a 426, air grabber and 4 spd is pretty much the top of the game for breed (winged cars excluded)."- Amen brother, amen!! 

[70chall440]

Now, if I can just get it reliable I will be accomplishing something.