Hi everyone I am pretty new here to the thread and have been trying to get as much info as i can from current threads but I could use some opinions. I have a 1987 Iroc with an L98 that is currently pulled from the car and stripped down to the block to head over to the machine shop. I'm planning on getting the Skip White stroker kit seen here from ebay.

http://www.ebay.com/itm/SBC-CHEVY-383-STROKER-KIT-SCAT-CRANK-RODS-030-FORGED-FLAT-TOP-PISTONS-1PC-RMS-/371081304469?pt=Motors_Car_Truck_Parts_Accessories&hash=item56662b5995&vxp=mtr
As for heads to help it flow better I was looking at the NKB 200 heads that Skip White also sells on ebay but I'm new to engine building as this is my first one, I dont know if these heads will be big enough for the added cubes.

http://www.ebay.com/itm/NKB-200-ALUMINUM-HEADS-64CC-CHAMBERS-200CC-SBC-CHEVY-327-350-383-NKB-200-274-/350938112290?pt=Motors_Car_Truck_Parts_Accessories&hash=item51b58aa122&vxp=mtr
I purchased a Holley Stealth Ram to sit on top of everything and need suggestions on a cam as well. That's where I am really unsure what to do. I'd really like some suggestions from you guys to help e decide where I should go. I would like to get the motor around 400hp 400+Tq and I'm trying to budget the best I can since I am only 20 years old. I'm hoping to spend around $2500-$3000 on the motor to have it ready to go back in the car in the spring. Give me some suggestions on what to do I would appreciate it. Thanks!

 

Those rods are not considered a stroker rods it you use them you are going to need to go with reduced base circle cam.

Step up to the Scat I beam rods rods with the 7/16 rod bolts.

I would probably go with a USA made head over some Chinese heads.

 

Those rods are fine and they already use the ARP cap screws instead of the traditional wave lock stuff. Looks and says like they have them clearanced for a 0.580 lift cam already which is fine for street spec sbc.

 

Welcome to TGO and good luck with this project and many more to come.

You will get alot of BS about skip white... His engine kits are not bad, same offshore made, use machined parts as other places sells. I don't see any prob with that really.

However, the kit you linked too has 2 vr 4cc pistons.. On a 383 that will cause your compression to be through the roof and will need race fuel to run.

With 64cc heads that kit with those pistons will put you at 11.6, 11.7 :1 compression

You could go larger cc heads to drop compression but I don't recommend that (more on that later)

You need a dish piston in a street 383, something like a 15 to 20 cc dish. That puts you in the 9.7 to 10.3:1 compression range which will run great with 92/93 octane fuel.

On the heads... Heads are high dollar items, that can be used for many years on many diff engines. You are young and into cars. This will not be your only modded engine/car. Don't buy a set of heads for 10 years down the road per say, but buy a set that can be used with good results 10 years from now on a diff build.

This is why I do not recommend going with a 70, 72, 74, 76cc head now to drop compression.. What happens years down the road if you want to build a 12:1 compression engine or a 327 or a 350 and you have 72cc heads... You have to have the heads milled way down.

Also, I would advise against the skip white $700 heads due to lower flow, (250's cfm aint bad, but it's lower than the avg aftermarket 200cc head) and long term use. Save another $500 to add to your head budget and get Brodix IK heads, pro filer heads, dart pro 1, etc

They flow more than the skip white heads, good trusted names thats been around much longer, customer service and support to back the products even 10 years later.. No they won't replace the heads but they will work with you to fix the heads at a good price if something happens much later on.

190-200 cc intake port is about right for a performance built 383

As far as cam goes.. It needs to be one of the last items you pull the trigger on. The cam must match the compression, CID, head flow, useage, stroke/rod clearance, etc

Can't figure out the best/needed cam until all of the above are nailed down.
But as a gen. idea based on the 9.7 to 10.3 compression range I suggested and brodix IK200 heads and primery use is street with some track time, I would say a dual pattern cam in the 230's* intake / 240's* exhaust duration @ .050" with a 110 LSA, with as much lift as you can get up to .600"

 

For a 383 engine to make 400 hp/tq will not be difficult. With a conservative tune running only 32* ignition advance and the "hot cam" my 355 made 325 to the wheels. At 400 hp/tq with at least a 15% drivetrain loss that would be putting down 340 hp/tq at the wheels. On the low end for cams to make that power 224*/230* in a 110 LSA or a good tuner with an efi 383 could probably get away with a 108 LSA and have decent vacuum. Otherwise the XFI280 is a good choice. Nice idle, good vacuum not hard to tune has a good midrange. I ran that for a summer. Those pistons are a -4cc dish so a regular fel-pro head gasket (1010) should have you at 11:1 compression ratio which will be fine for your purposes. You can run that with regular 92/93 octane. If you are worried you can just get a cam that bleeds off a little more cylinder pressure to give a lower dynamic CR.

I have no idea about those heads but I will not trust the purported flow numbers of any of these chinese made heads until I saw a reputable source or member post an actual flow sheet from an independent flow test. Look for a set of used aftermarket established name brand heads to buy first. With Eagle/AFR/Trick Flow/Profiller/Canfield/Vortec/Edelbrock/Dart you at least know the quality (and actual air flows) you will get before you buy them. Any name brand aftermarket head can put down 340 hp/tq from a 383. Any head in a 195 or 200cc intake size is what would work best for your goals. 64cc combustion chamber, angled spark plugs. For our cars with a 383 I wouldn't use a 180 cc intake unless it was a set of AFR and a really good deal. Likewise a 210cc intake would be too big for your goals.

 

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Hey guys thanks a bunch for all your advice in glad I posted. So it looks like I will stay away from those NKB skip white heads but the stroker kit is an alright purchase if I get the correct Pistons to get the compression ratio down to run 93 octane. I'll wait until I have heads and an assembled block before I purchase a cam. Another question for you guys would be on fuel. With the hsr I purchased I got 30# ford racing fuel injectors will those be enough for my goals and would I have to replace the stock fuel pump? And later down the road I want to get a fuel tuning set up I was looking at the ostrich stuff to burn chips for the ecu it looked simple enough to learn on to me and relatively inexpensive do you guys recommend any other tuners that are reasonably priced? (Under $1000 preferably) thanks again I have many more ideas for this build now

 

Weather you have a .300 or a .580 lobe both lobes are at the same height. At max lift on both cams the lifter is at the same height and its the nose of the cam that will have contact with the rods.

More lift smaller base circle.

The Scat Procomp rods have plenty of clearance is what I would recomend.

 

Yes, 30 lb SVO injectors are plenty. I'm using them in my 540 crank hp LT1, and also in my buddy's 600 crank hp stroked LT1. AFR's at max power are just fine. Furthermore, I roadrace mine, and the injectors are just fine for several years now, so don't be concerned about those warnings about running high duty cycles. The dataloggers that report that number are using ambiguous calculations and it's been proven to not be an issue by those folks going fastest with injected setups.
I have no idea if your stock pump will support 400 crank hp. The pumps that came in the LT1 cars certainly will.

 

What base fuel pressure? That seems like more power than i would expect from a 30 lb.... 600 crank would be closer to 500 whp depending on trans and i know a set of 42's at 43 psi base was getting up in the 80% dc range, iirc

 

Orr, like I said, you can throw that duty cycle calculation right out the window. For OEM warranty reasons, there may be some merit to their following guidelines like that to avoid the 0.01% percent of people that would take their car to Bonneville and hold it to full power for minutes on end and fail a fuel injector. And it's CERTAINLY a great marketing tool for anybody wanting to sell someone bigger injectors when they already have a perfectly good set
Get a high powered car like these on the dyno sometime and watch the AFR go richer on command as you make fueling changes, despite the duty cycle "number" telling you it's already at 120%.
Both my car and the 500+ rwhp LT1 I mentioned are running stock FP regulators (43'ish psi). The extent of his WOT pulls are 1/4 mile passes, but as I said, mine does roadcourse duty with no ill effects.
It's a moot point for the OP anyway. His 30's are certainly fine for his goals.


I know a lot of people reading this will say we're crazy for pushing injectors to their limits. It's no secret among NHRA class racers and "record chasers" that running injectors near full-open conditions gives more hp and more consistency to tiny fueling adjustments.

 

i'll never understand why people make building a 383 so difficult. the whole 5.7 & 6 inch rods usually cause some issues if not using cap screws on the rods. if people did it the "old school" way of using 5.56" rods,...no clearance issues. what are you really going to lose? 1-2% H.P.?
its so simple a monkey could do it. 400 rods with 350 pistons. no clearance issues.

 

Well thats the thing, several of us locals have done tests and seen duty cycle calcs coincide with afr readings. Maxed injectors out where commanded fuel doesnt change power. But we are poweradder guys with 60-127 lb injectors lol I know most tend to use more inj than needed and i also feel leaving an injector on more time and not having it close for any amount of time approximates carb type fueling and does make power...just havent seen a 30 make that much. Thats impressive

Regardless a typical street 383 is 500 and less hp and a 30 ford should be ok as its more like 32 lb at our pressures. That should work

 

Good you make that point about Power Adder vs NA, Orr. My experience in PA setups is very limited and I wouldn't encourage you guys to do what we do with our NA setups.
And yes, IIRC the 30 SVO's are set to about 31.5 pph in my program.

 

TPI is batch fire and LT1 is bank fire if I recall. I would think batch fire could create a richer mixture than LT1 s bank fire. The mode of injectors firing could also make a difference, along with Bosch 2 vs 3 series injectors. Higher fuel pressures could also ha e to do with it but you said stock 43.5 fuel pressure?

 

Batch fire (TPI and early LT1) vs sequential injection ('94 and up LT1) will make no difference in fuel demand of an engine on its injectors.

 

I absolutely disagree with that, I think you do also you just aren't thinking of it in terms of air fuel ratios. An injector that squirts once per ignition event can deliver more fuel than one that squirts only when it's perspective cylinder is commanded to. This is precisely why if I switch from bank fire to batch fire in my MegaSquirt I have to adjust down my required fuel or change the entire ve table by a small percentage.

 

Whatever algorithms MegaSquirt uses (I don't use it, so I can't analyze this for you), the required injector capacity will still be the same, whether batch fire or SFI mode. Maybe you don't realize that even with SFI, you're pretty much holding the injectors open full time as you approach their limit. The fact that you need to adjust fuel or VE table going from bank to batch just tells me that the MegaSquirt program doesn't have all the exact parameters to compensate for the transient opening and closing flow characteristics of your injectors. Not that that's necessarily a bad thing. It's tough to ever get them as exact as the OEM's characterize them; we just make adjustments to give the engine what it wants

 

I dont think it works quite that way. My understanding is that batch fires twice per revolution, which is two smaller pulsewidths. To calculate duty cycle you double the reported pulsewidth. Sequential fires once and that is a longer pulsewidth. You get the same amount of fuel either way

 

So with all this being said do you think the stock fuel pump in my car would be able to handle the flow of the 30# injectors I have or do I need to upgrade?

 

Lag time to open and close.
www.megamanual.com/mt29.htm#sc

 

If the stock fuel pump makes the required psi it will work. I am surprised the stock pump is still alive, I would expect it to die soon.

 

Thats exactly right and what I am saying. An injector that is squirted 8 times per 720* of crank revolution will release more fuel than one that squirts 4 times or that squirts twice or that squirts once. A stock ECM may have a calculation for the Stock injectors at the stock fuel pressure, but once you change injectors or fuel pressure it's wrong. MegaSquirt doesn't calculate lag time because there are far too many injectors out there to even attempt. But that doesn't change the fact that an injector would still put out more fuel with 8 squirts than with 4,2 or 1 with any ecm with the capability.

 

8 squirts, 4, 2, 1.......doesn't matter. The more fuel you command, and as you get near an injector's capability, just think of it as being open all the time. In the end, it's only the injector capacity that matters.


Regardless of what system the OP uses, 30 lb SVO's are more than enough for his needs.

 

May want to check this out first.
https://www.facebook.com/fredwhitepe...machinewarning

 

That was only one guys experience with an engine that they built, and it was only a very abbreviated version of one side. If you buy engine components to build an engine and you take measurements as you go you have no one to blame but yourself. Any engine I build I take the time to " blueprint" as I hope you and the op would. So to me that guys story doesn't mean much in the op case.

 

The rotating kit is good but I would chose other heads. I would not trust a no name head. You might be better off just dumping some money in to your stock heads or getting some better after market heads. Good valve train is important. The heads them self might be ok but every thing they used to assemble them with is probably junk. Spend an extra $300 on better heads.

 

The aluminum the Chinese use is not quality or even heat treated and would not be my first choice and there is no QC.

The rods look at the Scat Procomp rods more cam clearance panrail then the ones in the kit.

 

Sorry but I'm using 2 valve Pistons, 6in rods and a 64 cc TFS heads and .038 head gaskets making 11.0 compression and tuned the engine with 91 octane gas in California. The engine made 440whp with a 280XFI cam with a 114LSA. Keep your LSA around 112-114. A lot easier tune and to enjoy. HP peaks out at 6400 in my 388cu. If you're not trying to make this an all race car, you don't need a cam with a LSA under 112.
Too many people on will tell you certain things or the way they have tried and worked or didn't work. A lot of people here have race car on their mind when building an engine. So be careful who you listen too. Check my sig for a street car.

 

My compliments on a very respectable package for a full exhaust Cali-emissions car
I'm curious why the torque peak is way up there at 5100 rpm though.. ?
I'm running a 350 LT1 with a similar sized cam (228/234, .610/.610), but on a 108 LSA. My tq peak is at 4600 and the hp peak at 6400. I'd have thought your stroker tq would peak at lower rpm than mine. I'd say your Miniram and my LT1 intake should behave similarly in that respect. Are your TFS heads out of the box, or ported?

 

My heads are fully ported with 2.05 intake valves. Stroker motors makes more torque than a 355. My Miniram is ported also. It flows 414cfms. My heads flows 303/217@.600. The profile of the cam may have something to do with it.

 

I wasn't referring to the torque number, but rather the high rpm at which it peaks. Maybe with your porting, the port velocity just isn't there at lower rpm.

 

I could be the porting in the heads. It's kinda hard to say. But I tell you what, it made over 400wtq from 4800-5800rpms. Flatlined!

 

I disagree with part of what you said. I agree that cams with less overlap (112-114*) are easier to tune and have a broader/flatter power curve that may make street driving easier. I disagree that a cam under 112 LSA may be for a race car and not street cars. I ran nearly the same engine as you but with AFR heads instead of Trick Flow. Same cam and compression. I switched to a 110* cam with nearly the same duration. The idle is noticeably changed and doesn't pull as much vacuum, VE table from 1000-1800 is lower but after 2000 rpm the VE table on the 110 cam has increased 15% in some areas. No idea what the horsepower difference of that would be but I now believe that gains of 15% before 4000 rpm (haven't tuned past that yet, it's winter now) show that 110 LSA cam can be a good viable option for the street. As long as you have the proper compression, rear end gearing and tuning abilities because yeah, idle tuning is a little more challenging.

Good article about LSA and some other cam concerning aspects:
http://www.hotrod.com/how-to/engine/...mshaft-basics/

 

The 108 will make it peak lower. His 114 broadens the curve. Its gonna be flat from 4-5k rpm so i can see 5100 as peak of the "flat" curve esp with that ported miniram