Well It Finally Happened

[diymirage]

I had Mike at MRL rebuild my 360 as a 408
Machined my block, redid my heads, reused my can and ported my intake
Really, the only parts I bought was the rotating assembly
He put it together and dynoed it
4500 dollars later and I'm putting down 423 hp and 470 ft/lbs of torque

If I were you I'd build a mild 408 and put that blower back on

There's a lot to be said about the cool factor of a blown engine.

Not the way he blew the bottom end though

 

[lomchivok]

Approximately how much does it cost to have someone build one of these? I am on the fence as to whether I am going to build it or if I am going for instant satisfaction and go short block.

From start to finish 360 LA block decked and squared to pistons in the hole .008 with IMM indy heads shaved to get 10.0:1 comp, scat forged 4" crank, scat forged Ibeams and forged Mahle pistons, eddy airgap, hughes SER3438ALN-10 cam, hughes retro roller lifters, hughes roller rockers, hv oil pump, new water pump, deep sump oil pan, 3000 stall converter, fitech 600 power adder, internal balance and machining right around $7500. My 408 is installed and burning up the street. It easily goes sideways with a stomp on the gas at 30 mph with a 3.23 suregrip. Haven't ran it on a chassis dyno yet but will after the fitech learns a bit more. 400 miles on it so far and love it. 12.3 mpg highway light on the pedal in my 68 barracuda. Next is to beef up the 904 with this MODULAR TRANSMISSION KIT it can't handle the torque on the 1-2 shift.

 

[superchargeddrt]

From start to finish 360 LA block decked and squared to pistons in the hole .008 with IMM indy heads shaved to get 10.0:1 comp, scat forged 4" crank, scat forged Ibeams and forged Mahle pistons, eddy airgap, hughes SER3438ALN-10 cam, hughes retro roller lifters, hughes roller rockers, hv oil pump, new water pump, deep sump oil pan, 3000 stall converter, fitech 600 power adder, internal balance and machining right around $7500. My 408 is installed and burning up the street. It easily goes sideways with a stomp on the gas at 30 mph with a 3.23 suregrip. Haven't ran it on a chassis dyno yet but will after the fitech learns a bit more. 400 miles on it so far and love it. 12.3 mpg highway light on the pedal in my 68 barracuda. Next is to beef up the 904 with this MODULAR TRANSMISSION KIT it can't handle the torque on the 1-2 shift.

From start to finish 360 LA block decked and squared to pistons in the hole .008 with IMM indy heads shaved to get 10.0:1 comp, scat forged 4" crank, scat forged Ibeams and forged Mahle pistons, eddy airgap, hughes SER3438ALN-10 cam, hughes retro roller lifters, hughes roller rockers, hv oil pump, new water pump, deep sump oil pan, 3000 stall converter, fitech 600 power adder, internal balance and machining right around $7500. My 408 is installed and burning up the street. It easily goes sideways with a stomp on the gas at 30 mph with a 3.23 suregrip. Haven't ran it on a chassis dyno yet but will after the fitech learns a bit more. 400 miles on it so far and love it. 12.3 mpg highway light on the pedal in my 68 barracuda. Next is to beef up the 904 with this MODULAR TRANSMISSION KIT it can't handle the torque on the 1-2 shift.

Wow that sounds stout! This is the kind of info I was thinking about. I was going to do this slowly but I think I am going to jump in feet first (after some research and help from FABO knowledgeable members) I am going to look at the engine in the Dart today and maybe shoot a little video of the noise. Stay tuned.

 

[superchargeddrt]

Well this is the '69 340 block that I had sitting in my shed for 3 or 4 years and then under my work bench for the last 2. This block was given to me by a friend and I was sure that it was going to be at least at 30 thousand overbored but after measuring it is actually a stock 4.04 bore WOO HOO! It was missing the main caps so I will have to source new caps and have them bored. Does anyone know if all small block Mopar caps are the same? Let the fun begin.

We had to use a hone on it with some WD 40. We found a few areas that had some small gouges in it but it looks like 30 over should get them out. Now on to the machine work.

 

[yellow rose]

Your best bet is to just buy aftermarket caps. You can't use 360 caps because the mains are bigger.

I've never verified but someone mentioned 318 caps are bit shorter than 340 caps. If you have a complete set of 318 caps I doubt the little height difference will matter.

The biggest issue will be with the number 5 cap. You can fudge the 1,2 and 4 caps but 5 is critical and 3 is a bit touchy. 5 has to be as close as you can get it. If 3 is off a bit you can clean it up to make the thrust correct.

 

[moper]

318 caps are smaller and shorter. They're not as beefy, basically. If it was me I'd not bother using them. Buy aftermarket caps or find a set of 340 caps. Or take them off the blown up engine. I would figure on $7500-10K depending on what you are buying, what you are doing, or if it gets dyno'd.

 

[sireland67]

Who manufactures a decent set of aftermarket caps for a 340

 

[yellow rose]

Who manufactures a decent set of aftermarket caps for a 340

Milodon for one. I know there are others but I can't think of them now.

 

[diymirage]

I love my 408, gobs of power. If you decide to sell supercharger please let me know. I tried to pm you but it didn't work.

Can I be first in line if he decides to donate it?

 

[superchargeddrt]

Well I have another 340 block that I am being given. This one I know is already 40 over so I guess I will just swap the caps and get it align bored. Wow it's overwhelming the amount of research you have to do to build one of these. I don't want to make a mistake matching up the components.I was going to run my x heads that have had some work done to them with stainless steel valves and double valve springs but I think that good aluminium heads are needed here (I don't want to miss my supercharger). I want to be around that magical 500 horsepower with this and suggestion on Cam, Intake and heads would be greatly appreciated.

 

[1mean340]

I think there are a lot of myths about aluminum heads and boost. I used to hear guys say that they dissipated heat quicker so they allowed you to run more timing with boost. I have heard very experience builders tell me it is quite the opposite, that you HAVE to run more timing because you are bleeding energy out in the form of heat. Keeping heat IN is actually what you want, as it is keeping the energy inside the bore/chamber where it belongs. Iron heads won't distort as easily which should help with keeping the head gaskets sealed. Downside is weight and they are much harder to port. I kind of wish I went with AL eddy heads on my procharger build but I found a great deal on a set of well ported W2 econo heads. Iron heads probably aren't a bad thing when you consider how few head bolts we have too.

Just use something that flows good, that's really the most important part. Get that CFM up to around 275-300 and you should be able to make 500+hp with hardly any boost which is the desired goal. The less boost, the lower your intake air temps will be.

What I like about blowers is you can take a small cube motor like a 340, run a good head on it and make 500HP with a tiny cam and do it all before 6000rpm's. When cruising out of boost you have yourself a tame, 8.5-9.0 c/r motor with a small cam that doesn't require a huge stall or gears. No need to wind out to rotating assembly stretching RPM's to make your power. It makes for a very street friendly setup for a given HP level vs N/A. With that said, if you're "only" looking for 500hp, you can make a pretty streetable 500hp out of most strokers and it would probably be easier and cheaper. Since you already have the blower though, why not use for the cool factor alone. I think your goals may be a little too modest though. Not sure how much air that blower can move, but you should be able to make a reliable 575hp out of a boosted 340 with good heads without breaking a sweat if you do it right.

 

[MopaR&D]

B&M Blowers are Roots style.
They have 4 point teflon striped straight rotors.
Whipple, Kenne Bell, Lysholm are Twin screw.
ProCharger, Paxton, and Vortech are Centrifugal.

Gotcha, I guess my point was more towards the "positive displacement" vs. centrifugal aspect overall.

 

[superchargeddrt]

Well I'm on the plane coming back from England and I am excited to get started pulling the engine from the Dart tomorrow. I want to be able to drop the block off at the machine shop on Monday ( no Saturday hours arrrghhh).
So this is where the VERY KNOWLEDGEABLE members of FABO come in. I want to be able to run this thing on 93 octane pump gas,what compression do you recommend? I was thinking 10.5:1 max. This will be primarily used on the street but I will run at the strip a few times a year. I don't mind being a little radical on the street (never want to loose to a ricer or 5.0 Mustang). I was going to go with the Scat 416 forged kit and get the Total Seal gapless.rings to go along with it. I have had good luck with the Total Seals, they lasted almost 30 years and my compression has always been good and equal across the cylinders. I have the Crane roller rockers in my engine already along with solid roller lifters. The Cam will have to be changed as it was chosen for the supercharged engine. I could use a little help here. I value everyone's opinion here. The Dart currently has 3.55 gears right now with a 3000 stall converter. Opinions on cams and intakes are welcomed. I want to run aluminum heads that wont break the bank but perform well. Any help would be GREATLY APPRECIATED as I want to get the shoe on the road and I only can afford to do this once. Thanks again FABO!

 

[superchargeddrt]

No one?

 

[dart_68]

I think 10.5:1 compression ratio might be too high for 93 octane unless you get a cam that bleeds off so much cylinder pressure at low RPM that it's almost completely unstreetable. IMO, I wouldn't go higher than 9 or 9.5:1. Aluminum heads are ok but look into a good iron head. They are generally cheaper and can flow as good as any street aluminum head.

 

[superchargeddrt]

I think 10.5:1 compression ratio might be too high for 93 octane unless you get a cam that bleeds off so much cylinder pressure at low RPM that it's almost completely unstreetable. IMO, I wouldn't go higher than 9 or 9.5:1. Aluminum heads are ok but look into a good iron head. They are generally cheaper and can flow as good as any street aluminum head.

Thanks for your reply dart_68. I will most definitely look into a good set of iron heads. I have x heads on my current engine with stainless steel valves and double springs. They have had work done to them as well. I know that there are worked cast iron heads out there and they are in the running. I was wondering about the junk gas situation and 93 not being enough for 10:1 compression.Guess I will have to shoot a little lower or use better gas. Thanks Again, very much appreciated.

 

[DARTGAME]

A lot depends on how much you are going to swap over from your existing long block. I personally would go with aluminum heads if cost isn't a factor. That compression will be ok on 93 as long as cylinder pressure is where it needs to be. As far as intake, performer RPM would also be my choice for mostly street duties. Cam not to sure about but since you already have lifters and other valve train stuff I would stay roller.
Ian
p.s. I still think you should keep supercharger on it!!!

 

[superchargeddrt]

A lot depends on how much you are going to swap over from your existing long block. I personally would go with aluminum heads if cost isn't a factor. That compression will be ok on 93 as long as cylinder pressure is where it needs to be. As far as intake, performer RPM would also be my choice for mostly street duties. Cam not to sure about but since you already have lifters and other valve train stuff I would stay roller.
Ian
p.s. I still think you should keep supercharger on it!!!

Thanks for your reply and your opinion. I would like to keep the blower but if I build it high compression then I can't use it.Still thinking about it though. I love the way it looks but if I build the 416 right I will have more than enough horsepower.

 

[MiradaMegaCab]

No one?

A public vote on the strokers build, CR, CI and whether to use the blower would be interesting......
I'd say build a blown stroker.


I'd go with a blown 408!!
Icon pistons part# IC982 Has a -34cc dish and will result in a 8.8CR with 65cc heads. It's a forged 2618 piston perfect for boosted applications. Off the shelf pistons save money too.

 

[doogievlg]

A public vote on the strokers build, CR, CI and whether to use the blower would be interesting......
I'd say build a blown stroker.


I'd go with a blown 408!!
Icon pistons part# IC982 Has a -34cc dish and will result in a 8.8CR with 65cc heads. It's a forged 2618 piston perfect for boosted applications. Off the shelf pistons save money too.

I am in the process of putting together a new engine and I wanted to go with a stroker with some spray or possibly a turbo. Everything I saw said that once you get in the 600+ hp range with a stock block you are taking a huge gamble. I am with Leadfoot on this topic and say stick with the blower. There are tons of strokers running around but there is something special about a blown small black. Not to mention you bought the thing from a legend!

 

[Mopar Tim]

I am in the process of putting together a new engine and I wanted to go with a stroker with some spray or possibly a turbo. Everything I saw said that once you get in the 600+ hp range with a stock block you are taking a huge gamble. I am with Leadfoot on this topic and say stick with the blower. There are tons of strokers running around but there is something special about a blown small black. Not to mention you bought the thing from a legend!

Tons of stroked small blocks Mopars? Really?

 

[Leadfoot]

I was wondering about the junk gas situation and 93 not being enough for 10:1 compression.Guess I will have to shoot a little lower or use better gas.

I run a good solid 10:1(and change) with iron heads on 85 and have no problems. I'd like to hear some real numbers fro the guys at lower elevations. I'm at 5k feet and have never had so much as a knock or ping.

Tons of stroked small blocks Mopars? Really?

Well, they are 650 pounds each so it only takes three to make a ton.

 

[doogievlg]

Tons of stroked small blocks Mopars? Really?

I would be willing to bet that there is 2000 stroked small blocks out there. The point I was making is that there is more stroked small blocks than blown small blocks.

 

[superchargeddrt]

For those voting for the supercharged stroker, I am still considering it but part of the reason I was thinking about selling it is because it would help finance the new engine. It was cool to buy it from Dick Landy and I did get to talk to him once. If I build the 416 low compression then I have to stick with the blower. This engine was 8.5:1 . If I build it with 10:1 and go with very thick head gaskets and use a cam with a fair amount of overlap I might get away with it.

 

[MiradaMegaCab]

I used a PurpleShaft 509 lift , 292 duration, 108LSA cam on a blown 9:1cr 360.
The 174 blower was only able to put out 6PSI.... I was at max blower OD then went with a smaller blower pulley, exceeding B&M's max OD RPMs....This resulted in no additional PSI as the smaller pulley had less surface area and I was having belt slip issues....
With your additional CI the 174 blower might not be able to keep up while using a cam with a lot of overlap.