Engine planning 101

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My initial plan started with just wanting to be able to do a massive burnout through a stoplight intersection. Then it was (after attending the Mopat Nats in 2008 and watching the cars popping corn thru the pits) something with a similar idle. And then it was what level of street performance I wanted, and then after more trips to the dragstrip, what ET's I wanted to run. Logical downhill snowball type thing:eek:
 
I'd start with a block. Might want to know what type of block you have. Displacement is a big plus.
Bearing diameter should be established.
Be good to know the location of the cam or how many their are.
Piston diameter and bore clearance next.
OK im being facetious.
Dang man its a loaded question. You can just get all blueprinty that you want.
 
dartfreak75 said:
So what started all this is I'm working on my plan and I'm trying to work out any issues before I start buying anything. That way when I drop the block off I can tell the machinist exactly what I want and know what I'm getting. So I started with the intended purpose of the car
1)Street car
This car is has a an automatic transmission 999 torqueflite and 2.76 highway gears
So I know I want to run on pump gas so that is where the questions start. What scr/dcr can you effectively run on pump gas? There seems to be alot of opinion with no definite answer.
Moving on...
I'm reading my book (Larry Sheppard how to hot rod a small block mopar) and imo this is the worst book ever written. It is so jumbled with little factoids but no explanation or definition. So anyway I'm reading about valve to piston clearance and it tells you how to check it but again in order to do that you have to already have the engine assembled. So how can you plan for pistons and cams without knowing this information beforehand?
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Everything I asked you, that's where I start.
You're talking about building around an octane limit 1st. Point being ... have a target power range and set a perimeter in which it must function...then figire out which end you want to be on... safest or ragged edge.
 
dartfreak75 said:
Well my particular build that I have currently in mind is a 318. For a street car I want something that will be reliable and not over heat run on pump gas.
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Set it up 9.5 and find a cam that best suits you and will yield a 8.1 dynamic. Play with Wallace calculators to narrow down a cam range then come back for opinions.
 
Speaking only for myself...
The first and most important part of the plan is the budget. Pretty much everything is driven by what you are willing to spend. If you were serious when you said under a grand, it's gonna have to be basically a stocker. I just built a 351 Cleveland for a friend and the machine shop work was over a grand.
Second, I do a lot of research. I read about other builds, I talk to knowledgeable people, and other engine builders. I learn from their mistakes and successes. I write down what worked and what didn't especially when it comes to valvetrain stuff.
Comp Cams, Edelbrock, and many other companies will help you choose the right parts the first time. If you tell the guy at Comp Cams what you have in the shortblock in terms of stroke, rod length, pistons, what heads you are using... he can help you choose a cam, lifters, pushrods and rockers that will provide the proper valve to piston clearances.
You can build a nice 318 with 8.5:1 compression that will run on regular fuel and not overheat. Probably around 250-275 HP. And, you could use a lot of the original parts, which would save you a bunch of money.
 
MOPAROFFICIAL said:
Set it up 9.5 and find a cam that best suits you and will yield a 8.1 dynamic. Play with Wallace calculators to narrow down a cam range then come back for opinions.
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Lol you must be a mind reader that is exactly what I came up with!! Then a chose a cam to go with that 9.5 to get my dcr of 8.07 .
 
Dartfreak74, if your budget is <1000 dollars, what Jpar suggested is your best bet, junkyard 360 with a warranty if you can get it. Buy the engine, do the usual used engine checks, buy some gaskets if there are leaks you see. Stick with this plan.........stock engine.
dartfreak75 said:
I want to keep it under a grand.
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Dicer said:
Dartfreak74, if your budget is <1000 dollars, what Jpar suggested is your best bet, junkyard 360 with a warranty if you can get it. Buy the engine, do the usual used engine checks, buy some gaskets if there are leaks you see. Stick with this plan.........stock engine.
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Thanks but that's probably not the route I'm going to go.
 
Ok so I will spill the beans here is what I have in mind.
318 .40 over with speedpro h814cp pistons. Have the deck milled .037 to give me a .03 deck height. This with my 302 heads and a .045 felpro Hg will give me a 9.6 scr with the freedom to upgrade to 360 heads if I ever wish too. The cam (two actually) that I am looking at is a lunati voodoo I'm between the 10200701 and 10200702. The 701 will give me a dcr of 8.01 and the 702 will give me a dcr of 7.94. I'm leaning towards the latter. The top end is ported (mildly) 302 heads stock valves,headers and topped off with a 340 cast iron intake.
 
I don't think you could pull it off for under a grand and it's not really an option for this type of build but something I have been wanting to mess around with a late production 4.7 sohc engines out of a wreck for a while... One of the 2008 and up twin plug 300 plus hp outfits. If you get get a totaled vehicle with complete set up and could get around the anti theft hassles in the newer computer crap, you could build a pretty hard runner with 2.94 or 3.23 gears. I know from experience that an '02 Dakota with a 5 speed and the standard duty early weak sister 4.7 liter worked very well with 4.10 gears and 245/40-ZR 17's. The cylinder heads on the later ones are worlds better on the intake side... small block platform, lightweight & compact, would fit in a lot easier than a late hemi other than the technological nightmare. Might be able to get one on the cheap because nobody wants them, but finding a good properly maintained specimen would be crucial. Later ones have forged cranks, but pressed powder rods and thin crown pistons are the weak link and probably not easily upgraded with the 3.66 inch bore and 3.405 inch stroke. However, for a basic 300 hp turnkey engine package that lives best at the peak of the powerband it would make a great naturally aspirated combination... Forgive me for the ramble everyone, I like doing things that haven't been done yet!
 
So here was my process right or wrong. I knew I wanted a small block stroker so I looked at what I had that could be used. (W2's and a 360 block). Researched different combinations that used these parts and my hp expectations. I started with the heads getting them flowed and worked to the power level I was trying to hit. The guy doing the head work helped with locking down the combination in the compression and cam profile areas. Went with a very good machine shop that has the equipment and experience in mopars to handle the machine work, oiling mods and assembly. I used a highly recommended cam manufacturer for input on the custom ground cam. I talked with the head and engine guys before starting to get there opinions. I doubled checked the cam profile at a couple different companies to be sure. I'm getting close to the machining part of the build now and will dyno when done.
 
12many said:
My initial plan started with just wanting to be able to do a massive burnout through a stoplight intersection. Then it was (after attending the Mopat Nats in 2008 and watching the cars popping corn thru the pits) something with a similar idle. And then it was what level of street performance I wanted, and then after more trips to the dragstrip, what ET's I wanted to run. Logical downhill snowball type thing:eek:
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I feel you brother. This 318 started out as a regasket job. Lol
 
Here it is: I read what you said, but really, it IS about the budget. Why? Because your components and order of events will take place in accordance to what you have to spend.

So, if it's NOT about the budget, then the order of events would be this:
  1. The Short Block. Stout (meaning reliable) short block is your foundation. ARP bolts, cylinders measured, balanced, etc., obviously done to suit the purpose of the car/build. But see, you cannot do plan "A" if it's not in the budget, then you have to try to get a short block in "good" shape factory assembled, or a cheap re-ring kit.
  2. The heads. fuel mileage, performance, cold start ups, so much of it lies in the heads. Again, ideal a brand new aftermarket head (and having all tolerances re-checked by a good machine shop), obviously fitting the build intended also. But see, you cannot do plan "B" if it's not in the budget. So, you work with what ya got (home port, lap, etc).
  3. Cam. A good cam/lifter kit, in accordance to the build.
  4. Intake/Carb. Bought to match the block, heads, cam.
  5. Exhaust. Bought to match the build.
  6. Goes without saying, gears/converter to support the build.
 
318willrun said:
Here it is: I read what you said, but really, it IS about the budget. Why? Because your components and order of events will take place in accordance to what you have to spend.

So, if it's NOT about the budget, then the order of events would be this:
  1. The Short Block. Stout (meaning reliable) short block is your foundation. ARP bolts, cylinders measured, balanced, etc., obviously done to suit the purpose of the car/build. But see, you cannot do plan "A" if it's not in the budget, then you have to try to get a short block in "good" shape factory assembled, or a cheap re-ring kit.
  2. The heads. fuel mileage, performance, cold start ups, so much of it lies in the heads. Again, ideal a brand new aftermarket head (and having all tolerances re-checked by a good machine shop), obviously fitting the build intended also. But see, you cannot do plan "B" if it's not in the budget. So, you work with what ya got (home port, lap, etc).
  3. Cam. A good cam/lifter kit, in accordance to the build.
  4. Intake/Carb. Bought to match the block, heads, cam.
  5. Exhaust. Bought to match the build.
  6. Goes without saying, gears/converter to support the build.
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Thank you this is exactly the type of information I am looking for. Yes of course my budget is going to affect my build but hypothetically I'm curious to see how other plan there builds.
 
dartfreak75 said:
Ok guys lm starting from the beginning with a clean slate. When you are planning a engine build what!
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dartfreak75 said:
Thank you this is exactly the type of information I am looking for. Yes of course my budget is going to affect my build but hypothetically I'm curious to see how other plan there builds.
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Since my life in motorsports outside of anything in the dirt on 2 wheels is drag racing related my build would inevitably revolve around that. Secondly would be with or without a rollbar. And lastly would be am I looking for normally aspirated or power adder. To come up with a motor plan really entails the car as a whole....

The only advice I can give on this topic is don't spend money you don't have trying to impress people you don't know. What abodyjim wrote is pretty close to how I do things and if we were talking LA specific W2's would be on my motor no questions asked..... But that's not what you are asking. But whatever you do treat it like a business model and write it down somewhere so and that might help keep you on course of the original intent of your build....

JW
 
Larry Shepard's last book that I have pictured has list/matrix of several performance levels that you can answer for yourself when the guys ask the basic questions: vehicle weight, rear gears, transmission, how-you-drive-the-car, etc.
 
I was starting to think about upping the ummph in the cuda. 273 in it now. I was hoping to do it for approx a grand. Started hunting for something....2 318's and a set of 302's later....one with forged crank and the other came with LD340, so not a total loss. But I started pricing pistons out for the bores on either of the 318's and it was pricey. Machine work up here is pricey too, so the budget would have been put the window. Back and forth with good local mopar machinist, picking his brain and dropped off 302 heads for him to check.
He calls me and says "wanna buy a 340?" Yes and no...do I need another engine?
I bought it being too good to pass up, short block all freshly machined and bearings. I had my "fresh" x heads on the shelf, LD340 from the 318 prev purchased. Kinda stalled with the build but will get back at it shortly.
I "wasted" $$ but my machinist is an old mopar guy and this 340 was outta his stash, so it paid to talk to him and get prices on stuff. Fyi a rebalance on rotating assembly was $600 ish...too rich for me.
As someone mentioned talk to a good machinist.
Good luck.
Ps
Read lots of books like posted previously.
 
dartfreak75 said:
With all due respect your missing the point. I'm not asking what you would do on budget or anything like that. Like I said in the OP starting with a clean slate. How do you plan an engine build? This all about the learning process not what I should do on my budget. But what a reputable engine builder thought process is when planning a build. I have a plan with my engine that is not what this thread is about. I want to know what was your thought process and how did you go about planning your 408 build?
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410 build. I bought a block from the machine shop and have them prep it. I bought a stroker kit from Jags and had them install it. And I had them dial in the cam that I chose and put the heads on that I chose. But since then I've had the heads off and the cam out several times.
(Stop taking bong hits so you can get your thoughts together?)
 
Questions to ask yourself: How fast does it need to be? How mild/radical a car do you want or are able to tolerate? Do you want to build it with the option of upgrading later without having to change everything? Intended gear ratio and converter stall speed? Don't build your engine based on one of those 400 hp 318 magazine combos and expect it to run well with a stock converter. If you are not willing to run a looser converter, then you should keep everything very mild.
 
j par said:
410 build. I bought a block from the machine shop and have them prep it. I bought a stroker kit from Jags and had them install it. And I had them dial in the cam that I chose and put the heads on that I chose. But since then I've had the heads off and the cam out several times.
(Stop taking bong hits so you can get your thoughts together?)
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Are you referring to me taking bong hits?? Because my thoughts have never been so clear. I'm just trying to get info on the order of operation.
Did you read my plan?? ^^
 
dartfreak75 said:
Are you referring to me taking bong hits?? Because my thoughts have never been so clear. I'm just trying to get info on the order of operation.
Did you read my plan?? ^^
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Looks great! build it! do it! make it happen! I'll cheer ya the whole way...:thumbsup:
 
My $.02, and worth exactly what you're paying for it...

The answer is what j par said in post #2. Figure out what you want the car to do, then stick with your plan. When you have the goal firmly in mind, work backwards from there for which parts you want. Some choices will affect other choices, much like photography. You can't change one part of taking a photo without changing the rest of the parts. For me, I wanted a certain look stance-wise, so I started with wheel/tire sizes and reverse-engineered it from there.

I've been accumulating parts for about a year and a half for my build, and I'm just about ready to turn wrenches to make it happen. I can't tell you how many times I saw something appealing/interesting (SQUIRREL!) to tear off in another direction. Luckily, I've not actually gone down any side roads. But it's hard to resist the urge. This is a slant build, beefed up to be a fun driver but it won't scare any V8 in the neighborhood. I wanted spunky performance, good mileage (via an 833 OD tranny), running well on pump gas, and having the right "look" for wheels and tires. I have all these in hand, and by all accounts will wind up with exactly what I wanted.

So why do I still slobber over the BB 69 Darts I see?? :eek::eek::eek: It's a disease, but right now I can't afford more than one project.
 
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