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QuarterHorse

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I'm having a hard time deciding on what to do down the road. I can't seem to get any interest in my 340, and I don't want to set this car up for a small block first, to only then have to re-do it for a big block. Thus I'm looking at doing a big inch small block down the road. I realize I'll end up with different headers from one to the other which is fine, as I'm looking into something like a W9 cylinder head or something with some oomph to work with the big inches and nitrous set up. I'm looking for around 11:1-12.5:1 compression and running on E85.
The car will see some street time, so a completely filled block is out of the question, and so is an R3 block due to $$$. I don't want to be sitting at home on a hot day because I can't cruise my car down to the car nights at the local spots. Don't care if it won't last 80K miles so spare me that argument of the block not lasting at this point. Not being a jerk, I'm just not whiping my butt with 20 dollar bills.

Questions are this:

High flowing race heads for the SB Chrysler's are what?

What heads would you run? I'm looking for at LEAST 200CC intake volume.

What inch would you run? 408? 434? Something else?

I'll call the cam and converter companies when the time comes for them, but I'm wanting a rough idea of the basic components. I won't be skimping on the fuel system as I'm playing with nitrous again, and we all know that's where the problem starts when playing with the sauce.

Thanks for the input fellas,

Dustin
 
Ok we need to know how much hp you want and what you want the rpm's to be. You could make over 1,000hp with a nicly ported W9, 416cubic inch and N20. This is extreme example but you need to have some hp goals for us to go on. Also how many inches of vacuum do you need at idle and what rpm's do you need to idle at?
 
That's alittle over 700 hp at the crank. I would go with the biggest stroke that will fit and the best rods you can buy like oliver or you could go to Manleys pro I beam which are cheaper(1200 bucks). Also you can go with chevy rod journals and get some Howard billet rods for cheaper yet and the extra clearance will go along way when you have the grinder out clearancing the block. Pistons with probably be custom ones since the stroke is not all that common, Ross or CP can hook you up for around 700 bucks(don't forget the Howard rods are chevy size wrist pins). I wouldn't go W9 because they cost way too much to make them work and good luck finding headers that are under chassis. A nicely ported set of W2's can get you in the 550+range with a small roller cam plus you can still drive it around town. The rest of the power will have to be from N20. For the money I would just build the best bottom end you can, put a small roller cam and port your stock heads and use the N20 for the rest of the power. Either way I'm still not sure if the 4 head bolts per cylinder will take that much power.
 
Mopars are new to me. I lay'd down 530 rwhp on a little 306 Ford with a smallish 200 hit in the sauce. The cam was in the .570 lift range and duration at .050 was around .242 or so. It's been a few years for me. I was thinking something similar for a cam for this, a stall speed around 3600, tighter around 2800 if I spray it a lot (300+).

Your saying with my work'd X Heads I should be able to get that out of this or just get some W2's and start porting?

Also, since I'm not up to speed with my Mopars yet, what is the best stroker for a stock block? I know the 408 Ford's are about the best bang for the buck in a Windsor build, and the 331 is a lot nicer for the street than a 347 in a 302 block for various reasons. Would I be better off using my '68 340 block or going out and getting a 360 block?
 
W2's are expensive but if your starting fresh then it really won't be all that much more money if you go to a W2 head. W2 heads take a different manifold, rocker arms and headers but if your going to buy all of that new anyway you might as well go that route. Ported right they flow great on intake and exhaust; way beyond what you could pull from X heads unless you just completely went all out on the x head(raise both ports with epoxy.....ect.). As for strokers the 4 inch is the most popular and you can actual buy the whole rotating assemblies from many different places but most are forged and some even machined in china so have your machinist check everything. But honestly I'm not sure any of those kits will handle the hp you're wanting to run. I would call the manufacture and get their opinion before I'd buy the kits. As for the block it really doesn't matter in my books just find the block with the thickest AND most consistent cylinder walls. I know you don't want to hear it but the block will be a weak link in the build. There are many things you can do to help out bottom end strength but since you don't want to add block filler there is nothing you can do about about cylinder wall strength. Hope this helps you out and I imagine some one will chime in about your build.
 
A friend of mine has a 408 ford in a maverick, his car is very close to my 72 demon with a 408 in weight, cam, carb and the same gear. He runs a twisted set of heads (machinist ported) and I use STOCK CAST J HEADS that I have ported myself with no flow bench. My car runs a tenth quicker on most days but overall the cars are very close. I think your experiences with the ford windsor will apply to the mopar as well. Both are chevy eaters (; I would not worry about heating issues, my car actually ran cooler after adding hard block and cools off faster. Although I have not run it on a long street run, I would not be affraid to (if my car was street legal) Just my thoughts, Ray
 
Excellent, I just wanted to make sure when the time came I was going the right direction with a good stroker kit. Again, with a Ford 408 being a 4.030 bore and a 4.00 stroke they're the way to go. I figured the Mopar was close to the same bore/stroke ratio.
 
If you're into Fords, the factory block splitting should be known to you. Like, in half, down the cam bore? Mopars dotn have that. But, they do have issues with cylinder wall integrity, and the limited main possibilities. You say the R3 is out with no room to debate. So my response is, if you ever actually reach your goal, the block wont hold anyway. Not to mention that really, the best heads are for 48° blocks. Four bolt caps are a cool look, but there's not enough meat for them to really help, and in fact, will weaken the main areas of the block. Cylinder walls are notoriously thin. So huge NOS loads, and long strokes with short pistons, lead to failures. For the money you will put in to a factory block, you can buy a much better peice. By that I mean sonic test, sleaving as needed, cap replacement and fitting, 1/2 filling and the oil mods and cooler, boring, honing, squardecking and studs. You're over $2800 in labor and parts. Buy a block. You want to build a 5 story brick building on a wood foundation.
 
I'm saying very few Fords survive it using nitrous for very long, which is why there are other cheaper better block choices. You want 700hp, but you're doing it in a fairly violent and unforgiving way. Turbos would be better, and not as hard on the block. You can make the power. Anybody can make the power using the right parts. But for it to live, is entirely another matter. And if you're spending on the lower end to be reasonably safe at over 600hp, you're within hundreds of the cost of a block that will survive much longer, and make more power. 600 is the reasonable limit for NA or NOS use. I also use that for supercharger builds, because the drag on the crank nose can strain a block and crank. The numbers you want are not unrealistic. Expecting it to come from a 40+ year old factory design with some buttressing, and do it for very long, is simply not a solid expectation. I think instead of $5000 heads and valve train, I would buy the best block, crank, and rods, put heads that can move enough air to make 500hp on thier own, and pump laughing gas thru them to get the numbers you need. Better foundation= more power over a longer life span. The same Ford fellow I recall used Big SHot systems and Foggers to run high nines in his Fox Mustang and a 302. He split three seperate 5.0 blocks down the middle on NOS. He now runs a single turbo, much better block and rotating assembly, and the same car (with updates) runs mid 8s on street radials and makes tons of money on the street racing scene. If you saw it, it looks and sounds like a 12 second car.
 
I really don't want to debate power adders, as I have enough experience with each, and know what I want for my reasons.

I don't want to debate Ford vs. Mopar, as I'm not comparing 302 blocks, but 351W blocks that I have built to 800 crank HP with no issues splitting. Everybody and their dog knows about the 302 blocks splitting.

What I DON'T know, are Mopars, thus I'm asking on a Mopar board. Again, from the sounds of it, SB Mopars aren't what I'm after from what I've heard from you and a few other Mopar fellows on other sites. Am I wrong?
 
I think a better question to this whole post is to just ask who has broke a smallblock mopar and what was the build? All can still here and say this will work or it won't but personally I've never broke ANYTHING major in the motors I've built but I've never tried to make 700 at the crank either. The best knowledge comes from trail and error.

So who here has broke a block and what was the build?
 
Also the smallblock mopar has 4 inherent problems and none can be fixed cheaply. One the bottom end strength is not great for making a ton of power. 2 bolt mains, thin webbing and non solid pain rails. The second is cylinder wall thickness which again is a big limiter on how much power you can make. Most I've sonic tested have .275 for the thickest and 2.30 below for the normal before any bore is done. Third is the 4 bolts per cylinder which stinks if your plan is alot of N20 or boost. 4 bolts is just not enough to hold the gasket at high cylinder pressure levels. The last is the 59 degree tappet angles. These do not lend themselves to valve train stability in high rpm situations.

Even with all their problems they are very good blocks but also ALL these problems can be fixed with an R3 block.
 
A 700 HP S/B, 11 to 12.5 comp on juice and E 85? What are you wiping your butt with? LOL!!!

Thats funny right there I don't care who ya are.
 
So just for the sake of argument, why not start with a big block? I'm not sure what W-9 heads, a stroker crank, custom pistons and all that stuff costs, but I bet it's a lot. A 440 inch big block is gonna cost less than a 408 inch small block. And if you want to build a stroker, and spend cash on a set of high-zoot heads you'll stand a far better chance of ending up with a 700 hp engine that can be driven on the street. You might even be able to save some of theose $20 bills.
 
QuarterHorse said:
I'm having a hard time deciding on what to do down the road. I can't seem to get any interest in my 340, and I don't want to set this car up for a small block first, to only then have to re-do it for a big block.
Click to expand...

Right out of my opening paragraph. I would RATHER not, but it's looking like I can't take a few pages out of my Ford building days huh?
 
More power to ya brother! 700 on a stock block seems high to me but I dont know what knid of numbers can be made.

BTW, how fast do you wanna go?

Why not go big block? You are talking a whole lot of $20's to do a 700 HP S/B. Maybe you and I have a differant idea of how much it will take to do.
Don't know, love to see it. Good luck either way.
 
Lets make this two parts.

Build me a 500 horse stroker small block. Then add a 200 hit of the sauce on it. All we need to do is make the small block internals handle it, or are the blocks not gonna do it?

How fast do I want to go? I'd like to see bottom 10's but it's not a drag car. This car isn't caged, and won't be. It's a street car, built to be a sleeper before you turn the key. Let's not get off topic about the chassis, that's not why I made this thread, there are too many variables when people ask about ET, I don't want to go there.

Please read my responses as why I don't want to go BB. I don't want to spend money on building TWO transmissions, and chassis work, I want to do it once. If I could sell my 340, I would go with a stroker B block, the explanation was in my very first post, and just quoted again above the last response.

Thanks for the input fellas, lets just try to stay about the topic at hand.

Again, thanks for the replies,
Dustin
 
Okay, thats easy. Your 340, good 4 inch crank, stock rods are fine, they are forged. Light forged pistons, W-2's, cam in the 250 plus @50 range, easy 500 hp.

Have a fine day.
 
OK Quarterhorse, I couldn't ignore this thread for another minute.

In Jim Szilagyi book "How to Build a Big Inch Small Block Mopar" he states that the LA block can support up to 430 hp continously. Later on he states 500 hp. He's a Mopar engineer and most likely has/had access to data that we will never see. Having said that, this is what I know:

There is a member here who is running close to 550 hp naturally aspirated with a stroked stock 360 block. He did have a problem with a broken crank and has replaced it with the addition of a stud girdle and has not had any more problems. I might add that all internals are forged too and he races this car pretty often.

I'm with Moper when he states that aftermarket 4 bolt main caps are a bad idea as the main webs are too thin. Drilling this out does not help matters and may only serve to weaken the block.

So, my opinion is that a stock block can support 500-550 hp if:

1. You are using a premium rotating assembly consisting of all forged parts. The rotating assembly must be balanced even if the maker says that it's "pre-balanced". A top quality harmonic damper must be used.

2. The machine work must be impeccable!! Everything should be magnafluxed before assembly and the block should be blueprinted including align boring. Sonic checking the cylinder walls is must.

3. Use a stud girdle and top quality studs.

4. Block prep! Grind off all casting flash, parting lines, etc. Don't leave any stress risers.

5. Half fill the block with Hard-Blok or whatever.

I also think that making 500+ hp on E-85 or methanol will be easier on the block than doing the same on gasoline. Why I think so is for another post.

Now, will this block be 100% reliable with another 200 shot of juice? No way. Will it run? Hell yes, and really hard too for awhile. Mr. Szilagyi states that for 650+ hp applications, the R3 block is the only way to go. Main webs designed for 4 bolt mains, serious cyl wall beef, etc. The block itself even weighs about 50 lbs more than 340/360 LA block. Unfortunately, I don't think anyone can tell you for certain that "10 200 hp hits and she's a goner". You might get 1 shot or you might get 50 or 100, but it will go away and it won't be pleasant.

Hope this helps.
 
My favorite thing; Someone asks for advise and when the advise is not what they want to hear they bash and argue it.

Just stick with your Fords and good luck with them.



Moper, you can lead a horse to water but you can't make 'em drink.

Chuck
 
340mopar said:
My favorite thing; Someone asks for advise and when the advise is not what they want to hear they bash and argue it.

Just stick with your Fords and good luck with them.



Moper, you can lead a horse to water but you can't make 'em drink.

Chuck
Click to expand...

340 Mopar - What am I bashing!? I have people telling me a big block or telling me it won't work with no reason! Are you reading my posts wrong or what? I'm on here asking a legit question, and all I get is, "why don't you build a big block instead?" I've not been "lead to water" yet, accept for "ramcharger's" post. If you have nothing to add and to back up your reasons then the post is no good to me, even though I do appreciate input. What I don't appreciate are assumptions, which seems like what I'm getting out of your post. I would appreciate those comments be left out. I'm just asking questions as I have NOT built a Mopar, and am going to be doing one. I thought the Mopar "Family" was a tight knit group and could help a brutha out. Was I wrong? Please don't take this as any kind of static, I'm just here trying to learn, and ask more questions.

ramcharger - Thank you very much for your post. I do agree even with the Ford engines I've put together that drilling out for 4 bolts on a two bolt block is just bad news, and I have my reasons for that as well.

Speed Demon - Again, thank you for your posts. All this is going into consideration.

A forged rotating assembly was a given in my book, along with a girdle. Those things are just planned in a build to me.
 
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