I want to make around 700HP. I have a forged eagle crank, forged eagle rods in my 383. I have Al. Trickflow heads. I also have an F1 Procharger. What are some good pistons to run? (company/ style).

I know I need some dished slugs, thats all. I assume forged aluminum. Prices seem to be all over the place though. Also any idea on rings?

I will be having this built for me next month, I just want to have more knowledge before I start having my engine shop TELL me what to buy, ya know what I mean?....

I will also be looking for what cam to run. I know I will be running 9.5 comp ratio, 100% street driven with a T-56 and 4.11s. The car wights something like 3200lbs. Carbed and I don't have to pass emmistions of course. Oh long tubes and all that too.


Main question right now is pistons though.

Thanks for any insight.

 

like you said, your gonna want dished pistons, however if your running 9.5:1 to start with, adding boost is gonna raise your compression ratio, if you go much higher than 11:1 overall you can kiss pump gas goodbye, but you would be making tremendious power. just a thought

 

JE heavy duty inverted domes and rings will fit the bill.

Loose the 4.11 gears with 700hp. You will NOT need them regardless if its a stick or not I'd go with a 3.42 gear if running a 26" tire. 4.11's will just run through gears wayyy to fast and roast tires off which is going to happen with any gear.

9.5 to 1 comp with 14 psi or so for 700hp is fine on pump gas

 

Adding a supercharger will not raise the CR, it's a mechanical value of bore + head & gasket volume + piston volume & stroke. It's not even going to affect DCR. It will affect cyl. pressures though. (not even talking about boost being a result of forcing a volume through a restriction) Cyl pressure is key. Dished pistons would be the best if you're looking for high numbers. A set of bigger top rings will help cool the piston crown, get real serious and some oil squirters may be a good idea too (Bo Laws sells a nice DIY drill fixture)

 

Thanks for the suggestions, I will look into those JE pistons that were mentioned.

I will loose the 4.11s next year. This years budget is going solely to the SC install. And that is maxing it out. By far. lol.

I am not trying to make this thing live way way up in the RPMS, it will be drivin casually around to shows and to the movies and so on. Just a fun cruiser that is a little extreme. I will be running 93 octane with a blow through carb.

I figured 9.5:1 is a good place to be at if I am going to be cruisin' around a lot so it will not be a dog out of booste. I would rather loose top end to keep a more street friendly bottom end of the power curve.

Thanks for the suggestions. Is JE the only guys I should look into? I will post what the engine shop wants me to use.

 

Alot of companies make good pistons you just need to find something to give you that compression. 9.5 to 1 with a 64cc head will need closer to a 20cc piston dish. Alot of places make 12-16cc pistons which give 9.8-10.0 to 1 which is abit high for you. CP/Diamond/SRP i think has them.

JE i know makes a big dish piston. Its 28 cc and will give closer to 8.8 to 1 compression which is abit lower than you want but will work great. Shouldnt loose much low end with the blower type cam.
Alot of places can easily make what you want.

CP's 16.2cc dish will give 9.8 to 1 which is high, but could be ok on lower boost and definately ok with meth injection

 

Well I have no idea where my motor stands in terms of decking or anything like that, so I guess I will have to wait and see what the engine shop says when I get to that step.

I will keep those companies in mind when I start to double check the prices quoted by the shop. Thanks for the heads up.


Is it better to get floating pins or pressed? I know I can look this up, but I figure you guys that have posted here might be able to give me a quick insight in regards to how this might affect what I am going for, in terms of my motor.

 

sorry about the mixup about the cr, i was thinkin of cylinder pressure, i thought of that after i posted it, and in terms of floating vs pressed pins, i dont know too much advantage or disadvantage to either, but i do believe that if you have floating pins, it helps for gaining rpms faster, or so i have heard (used to have a nissan z31, and i was told thats why z32 pistons are upgrades)

 

I dont know the advantages/disadvantages of pressed vs fit. i think mine were floating but cant be for sure. The machine shop hung the pistons on the rods for me so I just had to assemble from there.

Be careful with what pistons you get. I'm not sure off the top of my head, i'd have to confirm but for boosted setups I believe you want to use 2618 alloy pistons. There are 2 alloys commonly used. 2618 and a 4032 alloy. Malhe makes a few good dished pistons for 5.7" rod (not sure what rod you have) but they are 4032 alloy and were not recommended for a boosted application. My machine shop guy (CNC Blocks Northeast) told me to steer away from the Mahle's when doing my 383 boosted idea. They are great for n/a but not for boost. Mahle even told him that. JE I do believe used 2618 but I think have both available. I'm not sure but they definately offer ring install instructions for both materials.

 

Very interesting. Thanks for the heads up. I will keep than in mind when looking.

How can cylinder pressure be calulated and understood? I know what compression ratio does, dynamic and static. But how do people controle cylinder pressure?

I have no idea what amount of PSI I will be running right now. I am sure I didn't get lucky enough to get my SC with the correct puly I want. I asume I will be around the 15 PSI mark but I have no real way of knowing unitl I am on the dyno.

Building cylinder pressure must be sort of like raising CR right? They both lead to detonation if you have too much if I am not mistaken....

Any more details with all this would be great. Sorry for not knowing much.

 

Boost is described as being equivalent to a higher compression ratio motor since cylinder pressures are effectively increased in both applications. Compression ratio itself may not change but the pressure does which is similar to a compression change.

Cam valve events do have effect on how you build cylinder pressure. Mainly rpms in which peak pressure may occur which should be peak torque.

Too much pressure can lead to hotter chamber temps which could preignite the charge causing detonation. Cooler spark plug ratings and effective engine cooling system helps as well as higher octane gas

 

Right. I knew that kinda stuff, but how to people measure cyclinder pressure?

I am only really aware of CR and DCR. Thats it.

Random side question... Mech water pumps push more fluid than electric right?

I know with all this power I will need a really good cooling system and want to know the best way to go.

Thanks.

 

FWIremember, press fit vs floating. Floating utilizes (2) spirolocks per side of the pin, mechanically locking it into the piston. Press fit does just that, relys on a interference fit in the piston. Problem.....can loosen up slip out and creat one helluva divot in your cylinder wall.

 

So floating it is.

 

here's alittle more on 4032 vs 2618 alloy. Some well respected individuals seem to think there are no real differences in the two for a boosted application as long as the tune is correct. I believe this to be the case as I've seen stock internals support big power with good tunes.
But general concensus is based on material properties, the 4032's are harder, wear better but since they are harder, they can crack easier than the 2618s. 2618's tend to be more forgiving in case the tune isnt 100% spot on. I like this for the initial tuning phase when you are working out the bugs slowly. Good chance you will be in mild detonation areas when working the tune.

http://www.speedtalk.com/forum/viewt...hp?f=1&t=19612

 

This is true. I may be. I really hope not to be because of how I am going about this build.

Once the engine shop has gotten me as close to 9.5 (max) as possible I will have them, me and some cam companies talk over what is best to use for my setup to make the power I want. After that I will ship my carb to "the carb shop" and they are supposedly able to to tune to exact specs if you tell them every last detail about your car. So I will do that and hope this all falls right into place.

fingers crossed.

Motor should be plucked out by the begining of next month! I am getting exited.

PS- I just bought my procharger bypass race vlave, NEW for under 300.

 

So, have you picked something yet?

Probably late but:
that's kind of a BS answer (not blaming you, a lot of the monkeys at speed talk have chased anyone worth anything away from that site in the last 5 years or so), but if the tune is correct he could run hypereutectic or even standard cast pistons, and they'll have tighter clearances, make more power, last longer/wear better, run better cold and lower emissions. The whole reason to run forged pistons is so that they live (they give some rather than fall apart) when you screw up/push it to the limit.

4032 will be lighter (it's less dense) more wear resistant (higher silicon), less cranky when cold/can run tighter tolerances (lower thermal expansion)... The only advantage to 2618 is that it's softer/more ductile so you can hit it with a hammer more times before you break off a chunk (but in the process it will look more like a lump of **** faster also).

OTOH, at least 1/3-1/2 the consideration there is the piston design. All those differences can be designed around/for, so you could make a good forged blower piston out of both... that being the case talking to and trusting the manufacturer you choose will make as big a difference as what it's made of. (that being the case, I'd still be leaning 2618 for most 700hp blower apps, but the more "street" it is, the more I'd be tempted to go with a 4036).

Floating pins tend to be more durable than pressed, although the locks on floating pins make me more nervous than a pressed fit (I've never had either clearly fail, but I've seen locks pop out (I'm sure that they were installed incorrectly), but I've never seen a pressed pin come out).

The fact is that unless you're willing to pay for totally custom pistons or machine your own reverse domes, your decision will probably come down to who has the right reverse dome/dish volume for your application.

Cylinder pressure: most of the time you're talking cranking cylinder pressure which is still not going to help you, and dynamic cylinder pressure it not that easy a thing to get a number for. There are "compute your DCR and then do X to account for the boost," but the number you get is not really useful, you change one factor that isn't accounted for in those numbers and you get completely different reasults, for example, a 9.5:1 combination with some cam timing might be OK with 15psi boost at 6000rpm on pump gas, but on a 20* hotter day or at 2000rpm it could be disasterous.

 

Thanks for the reply and all the info.

In the end it seems like I will see what the speed shop wants me to use and go from there as a starting point. I want to get the best piston I can without spending an arm and a leg to get it. I don't know what my deck height is exactly or anything like that so I will be learning that all once what I have has been torn appart. Then the real search for pistons can begin.

As of now, the car's battery is cahrged up and it is ready to go. Needs plates, happening next week. Then I will call the speed shop and setup a time to drop off the motor.

So I guess next month is when I will be posting here the suggested parts that they will want me to use.

This motor will be 100% street. I don't have to pass any emissions. I just want to make reliable power. I am not shooting for squeezing every last pony out and living on the brink of failure. I want something that is healthy and can last a long long time. The car definetly has something wrong with it now and makes 355 to the wheels and just feel a touch to slow for what i was shooting for. I am sure whatever amount of power this intercooled F1 setup gives me will feel like more than enough, even if I don't make it to the 700 RWHP mark.

I will post back in a few weeks when the real decitions are being made so I can get some help.

Thanks again.

 

I probably wanted go over 8.5-9.0-1 on a pump gas engine,you probably get by with 9.5-1,but if you ever want to crank the boost up,you'll could run into problems with detonation,personally I would probably build it with 8.5-1. 700hp should be relativley easy to do with the F-1,it's capable of alot more. For the camshaft,I would talk to Steve Morris at www.neweraracecraft.com ,he specializes in Procharger engines,and knows exactly what camshaft to run for what you are wanting to do,they are a little pricey,but the difference is amazing. We ran a custom Comp Cam set up for my F-1R 383,and we switched to a cam from Steve Morris,it was crazy how much difference it was.

I would look into the JE Extreme Duty Inverted Dome,they are 2618,will take alot of boost,and have pretty thick tops on them,we have pumped 23 lbs. of boost on them and not hurt them. I would run either Speed Pro HellFire rings or the Total Seal TNT conventional rings.

Hope This Helps,Brian

 

Sounds like good advice. I am hoping to find a grind that is not custom so I can just "copy" a build that has been done before. But a lot of times that is usually just not possible. Esspecially when I want to make this thing 100% street. Just about all builds that go as crazy as this plan to spend some time at the track and I don't.

Thats for the info.

 

My buddy is running the big comp blower cam on a 355 w/ an F1, car has awesome street manners and mid range/cruising power is great.

 

Not sure what piston you should use but hell fire or tnt rings a must. Static compression of 8 to 8.5:1 wont be lazy on the street
Good luck

 

I agree that 8 or 8.5 won't be lazy out of a 383, but with said, this motor is 100% street so a higher CR should keep it more awake.

I still think with my nice big intercooler I will be OK running low teens PSI wise. I will make sure to look into those TNT rings. Thanks for the heads up.

 

Running regular JE piston rings in my motor no problems. As long as the gap is somewhat more open, it will be fine. 18 psi so far no problems on a 9 to 1 comp motor in hot summer air with regular pump 93 gas. Conservative rich tune with conservative timing.

 

Awsome. Good to hear. Great to hear actually. I am a newbie when it comes to boost so pretty much everything worries me.

 

Man I wish we had 93 octane over here on the west coast!

 

Over here on the East it is just about everywhere. Sunoco even has 94.

Looks like I will be pulling my motor out next month some time. Can't wait to finally make a decition on pistons.

I figured out I am 90% sure my heads have 74 cc combustion chambers. Also learned that there are TONS of pistons for sale on racingjunk.com. Thats where I got my F1. Hope I can save money there. I will only buy new of course.

 

Yea the best pump swill we have in AZ is 91. You can find 100 octane at one or two gas stations, but it's like $6.50/gal

 

i ran a 150 shot of nitrous on my factory short block long ago, the cast pistons looked like new when i dissasembeled it due to rod bearings... so anything better than cast is good.

 

im using je inverted pistons in my motor not sure what cc id have to look and can't remember the rings i went thru the paperwok i have -28cc pistons and speed pro rings

 

Getting plates for the car today, and driving it down to the place where the engine will be pulled.

Piston decision about T-2 weeks it looks like.

Can't wait to see this F1 on the 385!!!!

C'mon bank account, you can do it! lol.

 

dennis sweet man what place is doin the install ?

 

SMG Performance, they are ripping appart my current motor and then, after discussing with me, buying new pistons, cam, springs and head gaskets and assembling it for me.

After that I may have them run the motor NA with a spare carb just to make sure they can check their work. I would also be nice to see an NA # so I can compare it to the booste later, even if one is engine dyno and another is wheel.

After that I take the engine back to my girls place to drop it in and start fitting all the brackets on there.

By then the intercooler should be on the car.

Gonna be a great summer.

 

nice gonna be wild

 

1. 9:1 is my vote
2. the cam selection will dictate your maximum boost pressure

If your cam is "tight" (peaky torque, lower duration, tighter lsa) you will need less boost to make big peak cylinder pressure numbers in your peak torque area, and that is where your biggest detonation concern lies.

with a looser (more overlap, longer duration) camshaft, yes fuel economy will suffer, less drivability will suffer, yes the engines dynamic compression around idle/low speeds will be more poor and the engine will feel more lazy...

but the tradeoff is... less torque. haha, yes less peaky annoying detonation causing torque... but it will be much flatter, you will run more timing, and it will make more horsepower and rev higher.

So really, decide your gearing scenario and drivetrain, if you have 4.11's and a wicked clutch you wont notice the losses from a larger cam as much as if you want 3.42's and a 700R4. then again, if you have a loose converter, you want the gearing and the bigger cam, regardless of the fuel economy issues because your drivability wont suffer much at all.

 

Thanks for the advice. The good thing is that I know everything else that is not motor related already.

Can has a T-56 out of a 93 T/A. Ratios: 2.66, 1.78, 1.30, 1.00, .74, .50

It has a Moser 12 bolt rear with 4.11s. Tires are 315/35/17 Nitto DR.

Clutch is a SPEC stage 3. Chromoly drive shaft, not that it matters.

Car will be 100% street driven to shows and fun on the weekends, maybe an autocross or drag once a year, so I could really care less about building the motor for either of those things.

Gas milage, drivability (torque down low), and good power from idle to 4 grand is where I am really interested in.

 

If you can, go with abit less gear. With that much power, 1-3 will be useless with 4.11's. Overdrive will be happy, as its just under 1600 rpm at 55 mph, but for a true street car with no or little track time I think 3.73's or similar will be better suited. Torque with the blower will be insane so you dont need alot of gear. Its just gonna spin. I have 2.73's and just coming off idle in first gear the car gets up quick as manifold pressure starts to approach 80-100kpa, and its not even beyond half throttle. A blower car should be capable of getting near atmospheric pressure in half throttle type conditions depending on the BOV/Bypass valve settings. If it stays out of any kind of boost, and only achieves 60-80 map on light acceleration off idle, then 3.42-3.73 gears will be PLENTY of gear for a 383 with those heads/cam.

3.73 is still abit deep in my opinion. 3.42's-3.55's will be nice if available. Dependign on the cam, your looking at 1300 rpm cruise in 6th with 3.42's. That should be doable with out bucking/surging with good tune and smaller cam. That should get you some good mileage. If not, keep it in 5th and thats 1700 rpm. Not bad at all. Use 6th for 65+mph highways.

Just my thoughts. 700whp is strong onthe street. If you plan to use any of that during your cruising, taller highway gears will help hook up. I know you have wide drag radials but that aint going to matter much at speeds below 50-60mph if your not in 4th gear or higher

 

Gears are out of the question right now. There is DEFINETLY no budget for that right now.

As things sit right now, in 6th gear I can go 80 MPH at 2000 RPM. Right now 6th is only for 65+ highways, even then if I slow down too much she wants to buck a cough due to the tune of the carb.

Thanks for the great advice Orr89RocZ, a lot of insight. Maybe gears will be the next step after the motor.

As things stand right now, I will just have to deal with 1-3 being useless.

I have a procharger bypass so I think I will be able to bleed off the extra booste at part throttle.

I am sure I will have a crap load of questions in a few weeks for you. Engine pull has been postponed for 2 week, girlfriend has a friend graduating colledge so there is a party to go to for that, week after that driving down to Jersey in the GXP I have. After all that I will pull the motor and keep you guys updated!

 

If by useless you mean fun/scary to drive then yes, 1-3 "uesless"


I also just realized you have a carb. If you care anything about fuel economy, you need to ditch the carb, but you knew this.

If you plan is to swap out the carb for EFI:
go with a smaller cam
go with a numerically lower gear
use less boost (and possibly a smaller blower)
so for example:
224/234 @ .050 112 LSA camshaft
3.42 gears + T-56
D-1SC procharger @ 10~psi with 93 octane
holly stealth ram : commander 950 ECU
result:
25+ mpg, 500+horsepower, very happy to daily drive, good low speed torque and responsive.

This is assuming you care about fuel economy and low-speed drivability.

if fuel economy is out, and you dont give a #@(*($*, then take advantage of those 4.11's:
234+*duration camshaft, 110-112lsa
4.11's + T-56
any fueling system (carb, efi, bucket of gasoline, etc...)
wait... what else is there?

This is where I point out the should be obvious:
Your cam choice decides where the engine makes power and how boost is utilized. If you want that tire shredding high rpm power you need a high rpm camshaft, which reduces fuel economy... and it WOULD hurt your low-end torque except that 4.11's makes it neglible. In other words, 4.11's make the low-speed torque loss of a large camshaft "dissapear". You wont care.

4.11's allow the engine to rev right up into its power band, and boost will come on fast, and traction will always be an issue, even without a blower... on the street with street tires. So to make your car actually "fast" you need to find a way to limit boost or even throttle % during the first few gears, on a turbo car I would just say use an AVC-R to do boost per gear...

So this is the result of a combination. My car with less horsepower and a smaller engine might pass your car because I am not spinning my tires at the light? If your combination is more mated to your wonderful T-56 you can have your cake and sort of eat it too...

You HAVE to take a video of this thing, passing 1-2-3 gears with this setup. I want to see this beast it must sound amazing!

 

Thanks for the great reply!

Here is a quick vid of me burning off my stock tires before I sold the rims. This is the car N/A of course as it was a few years ago.

But that is the same T-56, 4.11s setup.

http://www.youtube.com/watch?v=JiP5J76j1eU

As for getting FI, I want good gas milage, but I don't care that much.

I want this car to be a beast. Old school style. I like the sound/smell of the carb, suprisingly so does my girlfriend, lol.

So FI is out. Also it is way way too $$$$$. Smaller blower is also out, I might want to make 1000 HP some day and this blower will get me there.

As for cam selection I have started looking into what is out there, and i think I really need to wait for the engine tear down to see what my CR is going to exactly. But I will say one thing, this cam will be pretty small. I want gears 1,2 and 3 to be really fun. I will delay booste with the bypass valve making it shut only when the motor has very low vacuum. But that will get worked out during final tunning.

Only things I can change/ affor to change right now is pistons, cam, springs and small things like that. Blower is locked in, and so is the crank and rods. My ignition system is as well, all MSD stuff Digital 6 Plus box. I think I might keep my N20 just cuz I don't feel like selling it. I also have a 4" thick intercooler that is pretty big, so that is locked in as well.

I will def take a LOT of pics of the build and of how USELESS the first few gears are.

And if your car is faster with a smaller motor due to tracktion and all that. I don't really care. Like I said, it is all street, might not ever see the track. I just wanna have something rediculouse to drive to work!