texasTA

I have tried the LT1 specific forum and the Nitrous forum to no avail. I just have a few stroker related questions.

I am putting together a solid roller LT4 383 that will have a 300 shot on top of it.
Jordon Musser has been doing all the headwork on my LT4 castings and he has bought my valve train pieces (Cam motion cam, solid roller lifters, etc...)

I am at the point where it is time to get my motor built (the bottom end). So I have a few questions in regards to the bottom end pieces. My questions are:
Jordon stated that Eagle forged parts are good up to 800 horsepower.
So it looks like I will be going with an Eagle setup.

What type of rods do I need? Hbeam or Ibeam. Jordon stated to go with 6" rods for this combo.

What size of pistons do I need to achieve 11.5:1 compression? (my heads are stock cc, I believe 54cc)

With 11.5:1 compression, can you safely run 93 octane pump gas?

Also, this motor is going to need to be able to drive. I am going on a 3700 mile trip this summer (hot rod power tour), so she needs to be a cruiser. Is there anything extra I need to take into consideration to achieve my goal?

Thanks guys.

rskrause

1. Get the best pistons you possibly can.
2. H vs. I beam rods are a non-issue. There are good (and bad) rods in either category. Personally, I would go with Lunati "Pro-Mod" rods for a good medium price rod and not Eagle.
3. No way you can run a 300hp shot on pump gas without detonation, no matter what CR you choose.
4. There are lots of CR calculators available. You need your bore, stroke, gasket bore as well as combustion chamber volume, deck height, and piston dome/dish volume. To get a very precise estimate you also need the piston to bore clearance and the distance the top ring is down from the crown and the gasket bore, but these are trivial contributors.

http://www.rbracing-rsr.com/compstaticcalc.html
http://www.turbofast.com.au/Tfcomp.html

Rich

captaindbol

I have tried the LT1 specific forum and the Nitrous forum to no avail. I just have a few stroker related questions.

"I am putting together a solid roller LT4 383 that will have a 300 shot on top of it.
Jordon Musser has been doing all the headwork on my LT4 castings and he has bought my valve train pieces (Cam motion cam, solid roller lifters, etc...)"

"I am at the point where it is time to get my motor built (the bottom end). So I have a few questions in regards to the bottom end pieces. My questions are:
Jordon stated that Eagle forged parts are good up to 800 horsepower.
So it looks like I will be going with an Eagle setup."

"What type of rods do I need? Hbeam or Ibeam. Jordon stated to go with 6" rods for this combo."

On a new all out motor the price difference is not a factor so get the H beams and you'll never have to worry about anything


"What size of pistons do I need to achieve 11.5:1 compression? (my heads are stock cc, I believe 54cc)"

A flat top with the correct compression height should put you close

"With 11.5:1 compression, can you safely run 93 octane pump gas?"


Yes, with the right camshaft and tuning it is not a problem on motor. I do think that any serious nitrous set up needs a stand alone fuel system and high octane race gas though.

"Also, this motor is going to need to be able to drive. I am going on a 3700 mile trip this summer (hot rod power tour), so she needs to be a cruiser. Is there anything extra I need to take into consideration to achieve my goal?"

The only thing I can recommend without knowing anything about your setip is a stud girdle to lock in your lash settings. Loose poly-locks on a road trip suck bigtime. All of these questions are best answered by your builder. He needs to pick the parts that best suit the engine he has in mind. You are paying him for his expertise and quality work so there is no need to second guess him.

texasTA

3.) So can you run 11.5:1 compression ratio, and run pump gas without spraying. And then like when I go to the track, put in the race gas??? Would a setup like this work? Jordon was talking about wanting to put a stand-alone fuel system in my. Basically, he wanted to relocate my battery to the trunk and put a fuel cell in place of the battery.

6.) I am going to let the machine shop do all of that CR calcs, as I don't know all of that info.

1.) Would a good forged JE piston suffice?

Thanks

texasTA

Cool thanks man. I definately plan on getting in touch with them on Tuesday after MLK day. So are 6inch rods the right choice?

rskrause

The ability to run a given CR will depend on the cam. If it's a "big" cam, with a late intake closing event, you will be fine at 11.5:1.

JE is an excellent piston brand.

I never agreed with the whole separate fuel system idea. Added complexity with a very compromised result. For example, you have a 500hp motor and run a 300hp nitrous shot. If you have 93 in the tank and 116 in the secondary system your final octane will be ~(93*5+116*3)/8 = 105. Not all that high. Why not just do as I do: drain the tank and put in race gas when you are running the nitrous?

Rich

CCCCCYA

I would rethink that 6 inch rod a little too. 300 is a LOT of spray, and your going to want as much compression height as you can get. Moving the pin up that high isn't going to help much in the strength department. I'm thinking a 5.7 or 5.85 rod to gain a little meat up top. Sure the piston will weigh a little more (not much more though), but it would be prudent at 300 I would think..

But then again what do I know...

Dave C.

SStrokerAce

I agree with CCCCYA on the rod choice. A Eagle H beam would do it but I would rather have more piston there for a 300 hp shot

Injuneer

Ditto.... you don't want a 6" rod in a 300-shot nitrous motor. And you don't buy any old " good forged JE piston "... you buy a piston specifically designed for nitrous, with the correct strength, cooling, lubrication, ring pack location, etc.

Rich is also correct on the fuel... design a single fuel system that supports 800HP at nitrous level BSFC's, and run the required fuel at the track.

I let the pro's pick my parts, and they are probably over-kill, with maybe 1,000HP levels in mind for the future, but I don't have to worry about the bottom end.

racer7088

TexasTA,

You can get a 6 inch rod in no problem but the piston will be somewhat compromised. At a 1.125 CH you can do it reliably but only with .043 rings and at such a small bore you don't really have the hell fires etc.

I would do the 5.85 rod and use an Eagle H-beam for cam clearance so you don't have to run a low base circle. Then you can also EASILY run 1/16 1/16 3/16 cheaper Hell Fires then and the ring lands can be where you need them for much better strength.

We have some bad *** NOS pistons and you also need an NOS piston pin as this is not a place to save weight either. We use Wiseco/JE for most of our stuff as I can get anything I want from them and know several piston engineers and techs there.

11.50 to one is pushing things but with a large street cam you can do it otherwise you will detonate. Most of these LT1s have no power since they are always detonating so much!

Also tell Jordon Hi for me!

MEAN_SBC

I run a 350 shot on a 383 in my camaro, and have had pretty good luck with it. I went with 6" Scat 4340 rods with 7/16 capscrews, but I really don't spin it that high.. I shift at about 6500... I'm also runnin a Scat 4340 crank. I opted for the stand alone fuel system, but my car is carbureted, so my carbs at 6.5psi, and my nitrous fuel system is at 10psi. As far as pistons, I went with JE custom nitrous pistons, which really equate to the extreme duty dish pistons with hellfire rings, but I went at 10:1 compression.

Even with 10:1 compression, when I plan on sprayin, I run race gas in the tank, and in the nitrous fuel cell. There's no reason to take a chance runnin pump gas with that big a shot, cause with that much nitrous, detonation is a huge issue. Just a little, and even the best custom nitrous pistons will deteriorate.

If you're plannin on running that big a shot, I would definitely recommend that you dual-stage it. My best 60' times are launchin on 150, and bringin in the next 200 after it hooks...

1racerdude

You can run most anything parts wise that is 4130 or better on parts-timing, fuel,piston,crank,ect- as long as you don't rattle the motor. Different fuels is to dangerous to get a timing setting for and A/F-NO/F ratio.(ya never know what octane is going into the motor) If you measure VERY careful it's ok,but what a hassle. You will probably hurt something before you find out or make so many passes easing up on it the engine needs a rebuild. You need to find out what your DC is before making any decision on how big of a shot to run. Did I mention suspension and tires!!!!! There are guys running mid to low 1.3-60' on MOTOR & 10" tires down here in late Cameros, add in 150 shot onto that and it will take a TON of HOOK to keep it going straight. And a lot of chassis tuning to keep it off of the rear bumper.

It ain't just a matter of a 383+300 shot and go fast.

captaindbol

Rich, Injuneer,

This is slightly off topic but how much leaded race gas will the 0 2's and cat take before they crap out?

texasTA

Yeah, I totally understand that 1racerdude. And I ONLY planned on spraying a shot like that with race fuel. I guess I didn't specify enough that I was more concerned about running the pump gas on the street without the nitrous and then using the stand-alone fuel system with race gas and race gas in the gas tank for the track.

Lets restart this discussion. What would be a good setup (crank,pistons, rods) for a nice solid roller LT4 383 with the FUTURE plans to spray? I want this car to be able to be a "reliable" cruiser car. I plan on putting about 4000 miles on it this month in just the first week of June (Hot Rod Power Tour), so above all it has to be able to be a driver first and foremost. If I need to wait until after I get back from the power tour to setup the nitrous, then so be it. I just figured that I need to take into consideration the fact that I want to spray the car while I am doing the rebuild (383).

so, what would you guys suggest for:

Rods? Length and brand and style (Ibeam/Hbeam)
Pistons? Brand and nitrous/traditional
Crank? Brand

I was thinking of going with a Callies Dragonslayer, Pro Mod rods (5.85) and JE nitrous pistons, but Jordon stated that he ran a Eagle setup (crank/rods and JE pistons) up to like 750rwhp without any problems. he stated that the Eagle setup would be a good idea to save soem money.

383Z4ME

I researched the Bosch wideband O2's (pn: lsu 4.2) and there engineers say about two hundred hours. I don't think the cat will stand a half hour.

Rick