Brainstorming Ideas for 400-450 hp 360 Build

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fishmens67 said:
your 408 with iron heads IS respectable at 430 hp. But it is under headed for any future big hp gains.
If I'm building an engine and need to sink money into refurbishing heads, I'm moving to aluminum for a few more bucks.
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Only because i can work the heads myself and measure the improvements on my own bench am i not hitting the full on agree button. lol
But i hear you... and if some dont even have a decent set to start with, especially...then why not buy aluminum. They're like 300 each anymore and even cheaper name heads do better .350-.550 flow than a stocker as cast.
Definitely agree the 430 hp is respectable.. yet no more room without substantial work to them or a better head.
 
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MOPAROFFICIAL said:
You can make 425 hp pretty easy
360 .030 over 9.5/7.9 static/dynamic
.528 solid purple cam installed 4 degrees advance
mildly ported 2.02 heads x or j etc...basic iron that do the old 245cfm by .500 -very basic average etc..
rpm intake
750 carb
cheap headers or good ones.... does'nt matter.
It doesnt take much. 360 is a great motor.
Click to expand...


Shhhhh. Keep saying that and I won’t be able to buy them for 50.00 with those junk cast cranks. Lol
 
MOPAROFFICIAL said:
You can make 425 hp pretty easy
360 .030 over 9.5/7.9 static/dynamic
.528 solid purple cam installed 4 degrees advance
mildly ported 2.02 heads x or j etc...basic iron that do the old 245cfm by .500 -very basic average etc..
rpm intake
750 carb
cheap headers or good ones.... does'nt matter.
It doesnt take much. 360 is a great motor.
Click to expand...

I like the basic recipe for sure.

My normal hot rod engine build is a zero deck piston height. Bowl ported 2.02 iron heads back in the day that were replaced by well prepped not ported Edelbrock heads. An RPM intake topped w/a 750, 1-5/8 or 1-3/4 headers (larger headers were notably but marginally better. If you can afford TTI headers, that would be my choice for extra top end pop.) into a “H” or “X” piped 2-1/2 exhaust. Choose your muffler wisely because A LOT of power can be lost there.

The largest Hyd. FT cam I really like to use is 240*@.050. Something like a Comp Cams HFT @ 241/247 & mid .500’s in lift would get you there above the 400hp level for sure. Any work on the heads are a plus. This is as big as I would go for the street, for myself, what ever your good with is your call. I’m not really a fan of larger HFT cams on the street. Better off with a solid cam at that duration or larger IMO for improved rpm range. Add 1.6 rockers!


A 408 stroker will add a lot of torque and about another 15/20 hp at 500 or so less rpm’s.
 
fishmens67 said:
your 408 with iron heads IS respectable at 430 hp. But it is under headed for any future big hp gains.
If I'm building an engine and need to sink money into refurbishing heads, I'm moving to aluminum for a few more bucks.
Click to expand...
Completely agree. I had them and put $300 into them freshening them up. If I had to acquire a set of heads, 100% agree, buy a set of aluminum.

I did that myself and stepped up to CNC220 heads from BPE, Bloomer Performance Engineering out of South Bend. Rod is a great guy, he teamed up with Brett Miller and Bischoff on the CNC program and mill work. The heads will support more power than I am putting to them but I won't have to upgrade heads when I do upgrade the short block and upgrade to solid roller cam.
 
MOPAROFFICIAL said:
Only because i can work the heads myself and measure the improvements on my own bench am i not hitting the full on agree button. lol
But i hear you... and if some dont even have a decent set to start with, especially...then why not buy aluminum. They're like 300 each anymore and even cheaper name heads do better .350-.550 flow than a stocker as cast.
Definitely agree the 430 hp is respectable.. yet no more room without substantial work to them or a better head.
Click to expand...
Cannot disagree with anything you said.

I had the heads and didn't need to source a pair. I put a couple bucks in them to freshen them up, mainly updated springs and seal .

I was happy and the dyno tuner was impressed. That said, I was chasing a number and looking back with I would have stopped with what i had. I've since added an expensive set of CNC220 aluminum heads, a rather large custom solid flat cam, ported Victor 340 intake and a custom carb built by Thumper Carbs is being worked right now. The power increase is significant but so was the expense.
 
mpd12150 said:
I did that myself and stepped up to CNC220 heads from BPE

The heads will support more power than I am putting to them but I won't have to upgrade heads when I do upgrade the short block and upgrade to solid roller cam.
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And that’s the reason why you purchase excellent heads!
 
rumblefish360 said:
And that’s the reason why you purchase excellent heads!
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You are 100% correct. I'm glad I did the iron head build first so have that power comparison to judge both engine set ups. That said, dyno is cool and all, but it measures wide open throttle. That is not ideal for a street engine that will operate at all throttle ranges from idle to at times wide open.

The goal is to build a solid, reliable seat of the pants engine. If you are smiling when driving, that's the right judge.
 
Freakin A!!!!

When I build’em to drive’em, it’s how well they drive as well as the smile it puts on your face. It doesn’t take trick parts or the latest do dad thingy. Just good sense and good tuning. Done right, you can go fast with weird & Antique Parts.

As long as the air pump can breath deep and exhale well, it’ll move! Brand of part be dammed.
 
What if I started with a good running magnum 5.9. Keep the bottom end stock and just get good heads, cam, intake and carb? Put the money into good flowing heads?
 
cawcislo said:
What if I started with a good running magnum 5.9. Keep the bottom end stock and just get good heads, cam, intake and carb? Put the money into good flowing heads?
Click to expand...


Lots of ways to go about it but I always liked to start with a good fresh foundation (short block). That way in a few days I can update my build and never miss a race weekend.
 
cawcislo said:
What if I started with a good running magnum 5.9. Keep the bottom end stock and just get good heads, cam, intake and carb? Put the money into good flowing heads?
Click to expand...
IMO, this is a great way to go about it inexpensively.
(And what I have also done and am doing now myself.)
The first thing you need to check is the cylinder bores for wear. The engine should still show the cross hatching. If there good, probably, it still worth the check, the mains and rod bearings should be in good shape. Look for the lowest mileage 5.9 you can. These can normally be found at a good price.

IMO, skip the Hyd. roller in favor of a solid roller and solid roller lifters if the wallet allows of course.
Move to a aluminum cylinder head and port it.

Even a moderate cam (like a 230 or 236 @.050) will make 400+hp easy. Use a cam with a good lift to take advantage of the cylinders improved head flow. Check for valve to piston clearance! If you clear, let’er rip!

You can finish the engine off with;

A 750 carb
RPM intake
Headers - 2-1/2 pipe exhaust.
Upgraded distributor & coil

Get your gears and converter to match and it’ll be a great street runner.

Been there done that, on the second time around now. The only draw back is the compression ratio. It can be a little low, depending on your cam choice and ultimate goal.

Here is a thread to look at. Admitting his combo is t great, he still does well. Scroll down some and find it in post #4.
Click here —> Won my first race in a while Saturday night
 
Absolutely you can do it with iron heads. But, remember, guide and seat work are the two biggest costs besides port work and you need ALL THREE to get to that HP level, so then it becomes evident, that unless you can do your own guide and seat replacement, enlarge the bowl and seat areas yourself and port yourself, NEW HEADS are the better choice.
 
I’ll refer back to my first post.

This will guide the build.

360, 9.5cr+, speedmaster heads, rpm, solid cam, headers, 750dp, easily 400HP+........ unless the short block is crap.

It’s kind of a no brainer.
 
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Magnum blocks as said are inexpensive and tend to have less wear
mostly due to EFI and no fuel wash but also machined to tighter tolerances
450 can be made with solid, hyd, or HR
Late 360 or Magnum base gives you a choice
rumble is saying what I said about Iron heads
DYI or buy new aftermarket
Pick a modern combustion chamber
no X or J or other 60's design
Closed chamber is easier to get quench- no special pistons required as with old open chamber heads
 
Wyrmrider said:
Magnum blocks as said are inexpensive and tend to have less wear
mostly due to EFI and no fuel wash but also machined to tighter tolerances
450 can be made with solid, hyd, or HR
Late 360 or Magnum base gives you a choice
rumble is saying what I said about Iron heads
DYI or buy new aftermarket
Pick a modern combustion chamber
no X or J or other 60's design
Closed chamber is easier to get quench- no special pistons required as with old open chamber heads
Click to expand...
He can ,if he wants..
...but a closed chamber is NOT going to make or break the goal...and an open chamber will shroud the valve way less than a closed chamber and that means the open chamber will flow more with the same work done. Jim Leroy tested a lot of things in his time and i tested what i could that he told me.. and he is right. His ported 906 head is a testiment to this.
speaking of chamber shape by itself with identical port shape... obviously if the ports were w2 and the chambers were closed...no standard rocker head ' sans trickflow' would come close.
 
I've said several times you can make more HP with the open chamber head for the reasons MO mentions
especially you keep the revs above the torque peak
and
run extra special good gas
The traditional high compression big cam combination converter, gears etc

but you can make a better running street build with less sensitivity to timing and fuel with tight quench
remember this is a 4 speed build
no converter to keep the revs up and more likely to ping if lugged
build the tight quench motor
you do not want to always have to shift down when you would rather just give it some gas and go
 
So you want something that you can tear around on the street for fun and drag race and autocross? My recommendation has more to do with you than the 360. If you REALLY plan on doing all those things with it, my one suggestion would be build it with some room to grow. Forged bottom end and the best flowing head you can afford. I think the torque of a 408 might be helpful in autocross, but no real experience in it.
 
Preach it brother!
Just what you have stated has been the no brainer for decades and the build must be done for the situation at hand.

I say it often when speaking on my builds. There all in the street. Zero deck flat tops with a good quench w/ closed cha. Seed heads eating pump gas. Great performers all around.

On a race build going nutz, that open chamber is what I’m eye balling! Or opening up the closed chamber to de-shroud the valves as much as possible. Gotta get it to breath and allow that fuel to spread around.

Get the best high flowing head you can afford!

Wyrmrider said:
I've said several times you can make more HP with the open chamber head for the reasons MO mentions
especially you keep the revs above the torque peak
and
run extra special good gas
The traditional high compression big cam combination converter, gears etc

but you can make a better running street build with less sensitivity to timing and fuel with tight quench
remember this is a 4 speed build
no converter to keep the revs up and more likely to ping if lugged
build the tight quench motor
you do not want to always have to shift down when you would rather just give it some gas and go
Click to expand...
 
Wyrmrider said:
I've said several times you can make more HP with the open chamber head for the reasons MO mentions
especially you keep the revs above the torque peak
and
run extra special good gas
The traditional high compression big cam combination converter, gears etc

but you can make a better running street build with less sensitivity to timing and fuel with tight quench
remember this is a 4 speed build
no converter to keep the revs up and more likely to ping if lugged
build the tight quench motor
you do not want to always have to shift down when you would rather just give it some gas and go
Click to expand...

No one argued the benefits of quench fyi

I stated a fact that you dont need it to make the goal and you dont have any pinging issues @9.5 and an 8 or hair lower dynamic. that's like 155 psi. You'll be fine.
And if we start debating why not another .5 and get some more snap just for the sake of arguing for quench... well.. that speaks for itself. Ran many 340's 360's like this.
 
If I’m building a new street motor to run on pump gas, I’m not going to “chose” to not build a motor with decent quench.

If I have a pile of stuff sitting on the shelf I wanna use up, then it is what it is.
 
PRH said:
If I’m building a new street motor to run on pump gas, I’m not going to “chose” to not build a motor with decent quench.

If I have a pile of stuff sitting on the shelf I wanna use up, then it is what it is.
Click to expand...


I agree. You can get quench with the early heads, you just have to have a machinist who understands the piston CAN (and SHOULD) come out of the deck, or you are the machinist and you do it yourself.
 
I would chose the path of the least time and expense, and the most choices.

Zero deck & closed chamber heads.
No reason to reinvent the wheel.
 
PRH said:
If I’m building a new street motor to run on pump gas, I’m not going to “chose” to not build a motor with decent quench.

If I have a pile of stuff sitting on the shelf I wanna use up, then it is what it is.
Click to expand...
Spare parts build?
Love’em.
Doing on now. It is what it is and it’ll still make some good power. It doesn’t have to be a perfect combo, just perfect machining.
 
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