Drug this thing home (360). Now what should I do with it? - IT'S ALIVE!!!!

[471_Magnum]

Standard bore 360 short block.

Roadrunner has some issues with the 340 in it. Got an ear busted off the block, and a really annoying harmonic vibration. Don't know the internals on it, but it is externally balanced (albeit badly) and is a bit of a slug. Spent quite a bit of time over the summer getting it to the point where it could actually squeak the tires, but the performance can best be described as leisurely.

Been looking for a standard bore 340 block so I could re-balance and re-block what I've got. Maybe do a cam swap and some head work in the process. Unfortunately, standard bore 340s have proven to be rare as hens teeth, and really pricey.

This 360 cam up for sale locally really cheap. Figured it might be a good base for a 408 stroker. With the price of stroker kits, I can pretty much put one together for not much more than the price of a rebuild.

I want to maintain stock appearance (except for the headers), and my budget is modest. Going to stick with my T-quad intake and J-heads for now, possibly upgrading heads at a later date.

Give me your thoughts and suggestions for a stock appearing 408, namely cam selection.

[Troy]

Sorry to hear about the issues with the new ride. I have been able to find reasonably priced later model 340s but nothing in the 69-70 range for my Challenger. I bought a 5.9 Magnum (for the Barracuda before I sold it) that will eventually be going into one of my cars. Some day...

I am not very good with cams. Kamcuda is running a 408 stroker in his 70 vert so you might want to shoot him a PM. I think Ron may have helped in putting it together. The other guys I know personally all have trucks so the cam selection is different with the EFI.

The Magnum head swap is relatively cheap and they'll flow a lot better than any "LA" head. I will have a pair of stock ones that I can sell really cheap since I'm using a set of aluminum R/T heads on mine. No, it won't look exactly stock - but neither will a set of Edelbrocks. The Edelbrock Performer RPM Air Gap is the hot ticket for an intake but, again, not very stock looking.

Troy

[471_Magnum]

Any head swap will come later, but the Air Grabber limits the carburetor and intake combination, which in turn kind of limits my head selection. Not sure I can get a Magnum intake under there.

At this point, budget dictates I reuse as much as possible off the 340, including the entire top end, but I want to keep my options open for future upgrades.

[Troy]

I have a similar problem on the Mach 1 since it has a Shaker. I don't know that most Magnum carb intakes are any taller - but the Air Gap certainly is!

I'm not sure I'd worry about stroking it if you're keeping the top end from the 340 (ie. I don't know that you won't be handicapping yourself). Is it possible to just use the 360 block "as is"? Assuming the pistons aren't way down or there's some other reason you need to rebuild. Yes, stroker kits are cheap but you could be tossing a bunch of money down the drain if the heads/intake don't help move more air. Just thinking out loud here. Since I have to pay people to do this sort of work it's cheaper for me to go with heads and an intake than to tear into the bottom end.

Have you tried contacting Ryan at Shady Dell? Those guys only work on small blocks and they're always helpful on the phone (or email if they ever have time).

Troy

[471_Magnum]

Just about every retrospective that I've read on a small block rebuild these days expresses regret for not going the stroker route. I realize stock heads will be a handicap with a stroked short block but:
1. I'm not looking to build a rocket ship. Just something with more grunt than a 72 spec 340.
2. Heads can easily be upgraded later as finances permit.
3. The 360 internals are junk on this short block. Nothing there worth saving. I only paid $80 for the thing, so not much invested yet. I'd have been more selective had I wanted to stick with the stock stroke.

[Troy]

I see. If you need everything and you have to do the labor either way then it makes much more sense to go the stroker route.

I've been going through all my notes and all I have are cam recommendations for stock 5.9 Magnum with intake, carb and headers OR 408 with aluminum heads, intake, and carb.

Troy

[firefighter3931]

I'd look at the Comp XE275HL grind for a mild 408 street type build. That's the cam Rob runs in his Cuda and it is very streetable and makes excellent power. It'll roast the 275's for 200 feet ! 

Basic combo ;

-4in MP cast crank
-KB slugs 9.5:1 (less than ideal)
-275hl cam
-Box stock RPM heads
-RPM airgap intake
-#4779 Holley 750 dp'er
-TTI step headers with Dynomax Mufflers and 2.5in X-pipe
-TA 2800 stall converter & 3.55 SG


Ron

[471_Magnum]

I'm not going to have the top end breathing that Rob does since the intake, carb and heads will be stock. I already have the headers, 2800 stall and the 3.55s.

That XE275HL is about what I was thinking. It might be a bit more cam than needed, but it will leave some room for future upgrades.

Got the 360 tore down last night. No big surprises. I'll probably drop it off at the machine shop next week for cleaning and inspection.

[firefighter3931]

I'm not going to have the top end breathing that Rob does since the intake, carb and heads will be stock. I already have the headers, 2800 stall and the 3.55s.

That XE275HL is about what I was thinking. It might be a bit more cam than needed, but it will leave some room for future upgrades.

Got the 360 tore down last night. No big surprises. I'll probably drop it off at the machine shop next week for cleaning and inspection.

Jim, the 275hl is pretty mellow in a 408 but it idles nice and makes lots of manifold vaccum for easy tuning. If you have power brakes it will be no problem....this one made 16in hg at idle. Timing is 18* initial/35* total all in at 2600 

An LD340 intake is low enough and looks stock enough to fit under the factory hood. Performance is on par with the newer dual planes allthough it doesn't have the air-gap design. 

Here's a short clip of Rob's car with the 2.5in x-pipe exhaust and dynomax super turbo's :

http://www.youtube.com/user/robkamstra#p/u/4/hkFp6HBjp20



Ron

[471_Magnum]

I'll be keeping my eyes open for a LD340, or maybe a Street Dominator. Really want to maintain a stock appearance though. Both would probably sit on the shelf until the bug bit me to go faster (and budget permits a cylinder head upgrade).

[kamkuda]

I built this engine when the stroker cranks for small blocks where just available.  The pistons available at that time were very very limited.  The KB piston had a quench dome that I had cust to match the chamber of the eddy heads.

There are a lot more piston choices now but you may have to work on the pistons later if you switch to a closed chamber head. 

I would like more compression but truly it is an awesome street cruiser with loads of torque, excellent street manners, and runs on any fuel you put in it.  You could probably run kerosene LOL.

Best of luck 

[kamkuda]

very little notching reqd for the crank

[471_Magnum]

The Mahle dished pistons offered in most kits yield about 9.8:1 with 62 cc heads.

I see you've notched the bottom of the bores. From what I've read, clearancing is only required with H-beam rods.

Right now I'm leaning towards the Scat cast crank, forged piston, I beam rod rotating assembly.

Been thinking about what oil pan to use. Want a stock look, but the stock pan lacks baffles. Looks like Milodon has a stock replacement pan with baffles.

Pretty much tallied up all the Christmas receipts now. Looks like the next major parts purchase (the rotating assemby) will be after I get my tax refund. Meanwhile, I'll get the block to the machine shop.

[kamkuda]

I see you've notched the bottom of the bores. From what I've read, clearancing is only required with H-beam rods.

Notching will be determined when you mock up the engine and see how close the rod is to the block.

Have fun! 

[471_Magnum]

Notching will be determined when you mock up the engine and see how close the rod is to the block.

What rods did you use?

[kamkuda]

Standard rods.
ARP bolts IIRC

[Challenger340]

"Sometimes yer the Bumblebee, sometimes yer the Windshield"
I still dunno "which" we were on this one ?

We recently did a .030 over 340 for a "numbers matching" Car, using the 'Thumpr' cam the Customer supplied !
NOT, our first Cam choice obviously ! but the Guy wanted the "sound" ?
Surprisingly,
the little wee-40 popped out about 415hp & 390 Torque on the Dyno RIGHT AWAY, using the Stock Cast Iron Intake Manifold & Thermobog Carburetor !
Anybody who's played with Thermobogs knows how un-tunable they can be without parts, which we had NONE !
The Dyno Headers were used on the otherwise "Bone-Stock" appearing Engine.
Pretty shocked !
We were standing around in the Dyno room trying to look all "Intelligent", like we "knew" it would do this ?
NOT !

The only "tricks" applied internally, were some 2.02" Intake Valves in the otherwise 1.88 J head castings, and Intake Port porting ONLY, (Intake Port Bowl Volume), leaving the exhaust Port alone & Untouched, which seemed to counteract somewhat the Thumpr cams overembellished Exhaust profile for the "Lumpy Sound" ?
I'm sure we could have made more with a better Cam profile/Carb & Intake ?
Nonetheless,
kinda puts a wet rag over some of the "Stroker" builds I've seen ?

I am unsure of the hp/trq with the stock exhaust manifolds because we "stupidly" did not Dyno test with them, DUH !
We were only Dynoíng as a matter of procedure to break-in, and prove a product for delivery ? not expecting to chase any power ?
I don't even know if the Dyno headers helped or hurt ?
however,
I've since been for a ride in the HAPPY Customers Car with the Engine and stock exhaust manifolds, 3.55 gears etc., very FUN ride that gives a great accounting of itself as a "musclecar" with a wide powerband,  albeit, all done below about 6000rpm ?
NOT a Slug at all, that can roast the Balonies at will with a 2800 Stall Convertor !

Just some food for thought ?
I like Strokers, I REALLY do, and obviously if a Guy can afford the rotating assembly, GO FOR IT !
Just saying here,
but if you are considering using the stock Iron J heads on a Stroker, because of the cost factor,
sometimes, it may be important to remember,
even the stock cubic inch stuff can provide adequate smile factor ?
It's not the "Rotating seembly" by itself that pumps the Stroker cost, but the rest of the additions for the Stroker to work "well" throughout the rpm range that typically add to the expense ? Balancing/Heads/Intake/Carb ?

[firefighter3931]

The biggest advantage i see with going the stroker route is the increase in torque. Another 80-100 ftlbs is great when working with a heavy b-body using mild gearing. A stroker would be the only thing i would consider in a big car with a smallblock based engine. 


Ron

[471_Magnum]

Honestly, I could live with the modest power level of the 340 in this car. It's just the vibration that drives me nuts. But the cost of "upgrading" in the cubic inch department is almost too good to pass up.

[471_Magnum]

The motor got tore down last week. Loaded the block into the hatchback today and dropped it off at the machine shop. Going to get it cleaned and checked first.

[firefighter3931]

Hopefully no major issues with the block. 

Looking forward to your progress 


Ron

[471_Magnum]

Just dreaming out loud here:

360 block- 30 over
Scat 408 stroker kit. Cast crank, I-beam rods, Forged dish pistons (9.8:1 @ 62 cc) (just waiting for my tax refund)
J-heads (got 'em)... maybe upgrade to RHS LA-X heads if Indy has a good deal at the March swap meet
Stock rockers (got 'em)
Stock T-quad intake (got it)... or aftermarket upgrade if someone can point me to a spread bore that will work with an air grabber
Factory windage tray (check)
Summit stock replacement pan (w/baffles?), or Milodon stock replacement
Comp XE275HL
TTi step headers (got 'em)
2800 stall converter (got it)
3:55 gears (got 'em)

Other than the nuts and bolts stuff, am I missing anything?

[firefighter3931]

That looks like a great buildup 

Was talking with Dwayne last week and he just happened to have a set of the RHS heads in his shop for some cleanup work. They kick ass compared to the best factory heads and were on par with Eddy RPM's....he really liked them, especially at the price.  The only downfall is the added weight and cast iron casting which is more compression sensative than an aluminum head. He said the chambers were very nice. 

If you wanted to use a lowrise spreadbore manifold the Holley Street Dominator would work and provide a nice upgrade vs the stocker. 

Of course you will need a nice set of FireCore 50 ignition wires to light the fire 



Ron

[471_Magnum]

Those heads to appear to be one heck of a deal. That's where the project would seem to really start to snow ball though.

Just reading where we should expect $4/gallon gas prices this summer. Maybe sticking with a mild stock displacement rebuild is the way to go. Nice thing about the 340, I currently never give much thought to fuel price when I get behind the wheel...

[471_Magnum]

So now I've got a new dilemma. Just came across a "date code correct" standard bore 340 block.

Still in negotiations, but I think I can get it for less than 300 bucks. Haven't spent any more money on the 360 block yet.

Do I:

• 1. Grab it an rebuild the 340 with a few go-fast goodies
• 2. Stroke it. Toss the 360 block.
• 3. Buy it and shove it under the work bench and saveit for a day that will never come and build the 360-based stroker
• 4. Save my money. Don't need another big hunk of cast iron taking up space. Stick to the previous 360-based plan.

Don't just have 300 bucks to burn, so option 3 won't happen.

If I'm doing a stroker, I see no reason to "waste" a 340 block. The 8 additional cubes aren't worth it. But having the 340 block can make that a "game time decision" to be made once I open the old motor and see what I've got to work with.