Hey TGO.. I just got through reading the Lingenfelter book on modifying SBC's for about the 4th time. After taking extensive notes both on paper and in my head, I have decided to present the pieces of this build that I have (or atleast I think I have) decided on for you to critique. I would really appreciate it if anyone who reads this gives some input on what will or will not work.

First off let me say that this will be a daily driver, and because of cost restrictions, I have decided to stretch the project over several years. Being a college student is not exactly the best position to be in while also being a speed junky.

So here goes.

I am starting with what I believe to be an L98 out of (originally) an 87 Iroc (one piece rear main seal, correct? and is it 2 or 4 bolt mains?). It is currently in a friends 89 trans am that does not run due to fuel problems, or so we believe. I am going to get the block checked for any problems with a local place that I THINK I can trust although I have never had machine work done with them before. Unfortunately they are just about the ONLY local place.

Anyways, what I would like to see mostly torque from this build, as it is designed to be a street car. It will start N/A, but I eventually want to supercharge it.

1)CRANK - A 400 crank, obviously needed for the larger displacement, but not so obvious to me is the need for a 4340 forged steel crank. Is this necessary for my eventual goal of 400+hp/tq? Also, I believe it is possible to buy the cranks that are already machined for a stroker 350, not having to grind down the main journals, correct?

2-1/2)PISTONS/CONNECTING RODS - I would like to stay on the simple side, and compression can't get too high, so flat-top was the first that came to mind. With the 68cc comb. chamber on the heads I want, would forged flat top pistons be ok? Is there a specification for the pistons I am missing? Also, I was looking at getting the 5.7inch connecting rods mainly because of their availability and cost. Any input on this?

3)CAM-This is the part I have the least understanding about. I think I have definately decided on the Hydraulic cam.. but flat tappet or roller I don't yet completely grasp. I believe a flat tappet is my best choice, but does this restrict me later on down the line? 224@ .050inch lift was suggested in the lingenfelter book.

4)HEADS - Aluminum heads, It seems that the brodix -10 heads with the 185cc intake ,2.08/1.60 Intake/Exhaust, and 68cc combustion chambers are a good choice for my torque friendly build. Any suggestions? Also, what is the deal with the degree of the heads? I was unclear on this.

5)A side note kinda.. but as I understand it also very important, the bearings. "Clevite 77" bearings were "the only bearings used" by lingenfelter for his engines, should this hold true for me as well?

6)VALVETRAIN - Another grey area for me. Because I was thinking hydraulic flat tappet, must I now get hydraulic roller rockers? Or am I way off. If the former is true, I have seen 1.6:1 roller rockers be very popular on these boards, combined with a stronger spring (what spring? anything I should know about this?) will these work with my setup?

7)INTAKE - I would really like to use the Superram. My biggest fear is, considering the fact that it is a daily driver, will this pass emissions (I live in massachusetts).

8)EXHAUST - In the book it suggests that for a 350hp max 383 that I use 1-5/8 inch headers, which is probably more realistic for this N/A build. However, I do plan to eventually supercharge the car, and if this N/A build could be worth over 400hp, is it possible to go with the 1-3/4 headers without suffering the tq loss at low rpm's? I already have 3" mandrel bent coming from the cat-back with a flowmaster 80 series muffler (I know.. not the best flow-wise, but I love the exhaust tone)

9)FORCED INDUCTION - Finally, the last step I will take is to supercharge this bad boy. My first and possibly most important question is will a supercharger work with the MAF system? I had in mind the vortech b-trim supercharger. I do not want to put too much boost into it because I do not want to have to deal with doing tons of work to make space for a larger supercharger, and/or an intercooler. I would like maybe 9psi max. Correct me if I am wrong, but 9psi doesn't seem like a lot to me (and I could be very wrong, not too sure.

I understand the longevity of this post may have made many quit reading as soon as they scrolled down and saw more. But with the limited knowledge I have, and equally limited resources around my area, I really hope someone can clear some of this up for me. Thankyou very much for your time and any input you could have given me.

Hopefully I can become a more involved member in TGO now that I can stop trolling and start talking with my new project coming up!

 

dont know too much about alot of the questions asked but i do know that the superram IS emissions legal so u wont have to worry about passing smog

 

The L98 block will be 2 bolt mains. And you are correct that it is a 1 pc rear main seal.

1.) There are such things as cranks that are made with a 3.75" stroke and are set for the 350 main size. To safely acheive 400 hp off the crankshaft (which is what I assume you are after?) You don't need 4340. You could get away with a lesser grade. Perhaps an Eagle SIR or a Scat equivalent would be to your likings instead. The Eagle is cast steel, so it is stronger than stock but not as strong as 4340. It should be fine for 400-450 hp, as long as you don't go crazy on it. Since you do plan on supercharging (which would probably take you clear over 400 hp), then the higher grades may be decent.

2a.) Most aftermarket crankshafts specify the rod size. Again, both Eagle and Scat make a very cost-effective alternative which may be something to look into. For Eagle, they are the SIR series. And as far as I know, there is no difference between the 6.0" rods and the 5.7" rods. Their biggest advantage is the rod bolts. They don't use the factory pressed style. They use decent aftermarket. (rod bolts being the weakest link in the rotating assembly). Strengh issues are the same here as for the crank.

2b.) Do you ever plan on really beating on the engine? How about nitrous? If this is just an engine to get you up and around, hypereutectic pistons will do just fine. There is no definite need to get forged. Yes, forged does offer the strenth advantage and whatnot, but, hypers are still durable granted they don't take to detonation as kindly. Just plan it smartly aned hypereutectics, even cast pistons would suffice. Build for NA or build for boost. Don't do both. If you want to build for boost, stay with a lower compression forged piston (piston with a slight dish).

3.) For cost effectiveness, yes, a flat tappet would be your best bet. An L98 block is a roller block, a factory roller to be specific. If you wanted to really get into it, You could look up some various aftermarket cam grinds that utilize the factory cam designs. Comp, Crane, etc, they all make cams that are designed to be compliant with the factory roller hardware. The LT4 HOT cam could also be used. Just keep in mind though, those are a bit more pricey. They are about $175ish for the cam, then you still need the roller hardware (unless you have some) and some good valve springs. A good Comp K-kit for a decent flat tappet cam runs about $300-400 for pretty much everything except the pushrods. As far as which particular grind, heads, compression, rear gearing, stall speed (if using an auto - I've been typing so long I don't recall which you have), and rear gearing all come into play for this. My suggestion is decide where you want to go, then pick a cam that gets you there.

4.) This ALL depends on how much money you have to throw around. If you can swing the price, AFR makes some great heads. For about $1050, you can grab a full est of Trick FLows, which are another great head. The degree thing indicates the relation between the valve and the piston. Factory is 23°, most aftermarkets are as such. Only when you REALLY need fo flow air should you need to look at 18 or 15° even. Stick with 23° All the parts for the top end you see listed are more than likely listed as compatable with the 23° setup. This includes the intake and what not.

5.) Clevite seems to be hit and miss around here. You will see some that say go ahead and use them. You will see others say, no, don't use them. I personally prefer Federal Mogul bearings all around (cam, rod, and mains).

6.) Rocker arms are rocker arms. When you see "hydraulic" or "hydraulic roller" listed, that only implies the tappet form. A rocker will be listed as "roller tip" or "full roller." It's job is to transform the upward motion of the cam to downward motion in the form of opening the valve. That is where the ratio comes in to play. A 1.5 ratio opens the valve 1.5 times more than what the cam lift is. A 1.6 opens multiplies the cam lift by 1.6. So in essence, it is a "cheap" way of skating out a tad bit more lift. Any rocker out there will list the advertised lift for a 1.5 ratio. My advice would be to find a cam with lift you like, a duration that suits you, then see if you want to tailor the lifts with rocker arms or not. For a roller tip, I would suggest a Comp Magnum and for the full roller, I would suggest the Pro Magnums. Both are steel, not aluminum. SO they have a much better fatigue resistance strength and both will be a lot more sturdy than the factory flappy-style stamped. As far as springs go, determine if you want flat tappet or roller. You can get suggestions from there out. In the end, my ultimate suggestion is to make sure you match the springs to the cam.

7.) This has been covered.

8.) A good 1 5/8" shorty header and a good 3" cat back would be good. Because you need emissions, make sure you get a set that is, well, emissions legal. Hooker (I think) makes a set, and I know SLP makes some. For boost, perhaps a 1 3/4" primaries.

9.) The basis of the build is here. Build for boost, or build for NA. Depending on how you go about things, it may not be the best to go for both. Pistons are completely different, cam grinds CAN be different, although the actual valve timing isn't that far off.

What are the plans for the rest of the car? You will be infringing on the areas in which 700r4's can no longer take the power. Same with the rear end, both especially true if you run boost. Is there a budget that you would like to set on this? That would help determine a few things such as valve train and heads, as well as, well, the rest of the engine.

Also, take a look around. Try a few searches. See what other people are running as far as boosted 383's.

Ok, I'm done.

 

I don't know what your requirements for emissions are in MA; but if you don't have a visual and a CARB type certification setup, then I sure wouldn't put a Super-PITA-Ram on anything I planned on driving regularly. Those things are about the most difficult design of all possible FI replacements to service.

I'd recommend a MiniRam. It'll give you more power in addition to being easier to work on. It just doesn't have EGR, so it wouldn't pass a California visual; and you might have to do a bit of chip programming to keep from getting a Check Engine light for the ECM not seeing that in its diagnostic routine.

Buy a "kit" of crank, rods, & pistons; not because they're better that way, but rather, because if either you or your shop can't be trusted to make the compatibility calls, you have somebody else to fall back on. Scat & Eagle both make cranks & rods that would be fine for this sort of thing. Flat-top pistons would be fine with 68cc heads.

I quit using Clevite bearings about a decade ago due to their quality control being anywhere from very poor to non-existent. I've been using Speed-Pro (Federal Mogul), and that's what I'd recommend.

Use a hydraulic roller cam. DON'T downgrade to a flat tappet. Use a good quality steel roller rocker if you can, such as Comp 1300 series, or Crower. Avoid aluminum rockers for street use.

DO NOT hallucinate that you're going to build a max effort motor, and "later" just walk up to it and "add" a blower to it. Design the motor from the ground up for one or the other. You can't do both. 9 psi isn't a whole lot of boost; that's around a 50% increase in HP, max. Probably more like 30-35% in the real world. Not a huge deal as far as the bottom end in other words.

I think you'll find that if you pick the induction system properly, you won't need or even want to spend the extra money on a blower.

You haven't mentioned a transmission, torque converter, or gears; let alone any suspension work. I can about guarantee you, you will not get your money's worth out of a mountain motor of some sort, without paying attention to those things. Power is worthless if you can't hook it up, or if something tears up every time you try to use it, or if the car doesn't allow the engine to run at a RPM where the engine is happy. Too many beginning car builders make the mistake of spending all their time money and effort on the engine itself, and neglecting all those other things. It's an insidious mistake, that leads to disappointment, and getting beat by people with a fraction of the money tied up in their cars, as you have in yours. Which is highly embarrassing as well as a major discouragement.

 

.

 

Been doing this to me alot lately....

 

i had this long typed out response, then read stekman's reply and i wasn't saying anything he didn't.

so, read his post carefully and add his points into your notes for the motor. good advice, really.

 

Thanks so much for all the input, as well as pointing out the fact that I left out some very important aspects :P

The transmission is a 700R4 that was rebuilt about 5k miles ago with a shift kit. I would love the idea of the T-5 swap, but from the sounds of it, the tranny and the swap alone would cost more than the entire motor build. Although if I really need to get it I will.

The suspension will be seeing extensive improvements this winter. The only thing I have right now are spohn's SFC's, but I will be talking to an expert on what to do to fit my specific application (lot's of power :P).

As far as the rear-end, I have planned to upgrade this for a while. I was told it was a Posi-Rear when I bought it, and for a long time I believed it because it always seemed as though the wheels spun together, but lately with the cold weather and the snow I have realized that this is NOT the case =/ I'm looking to get a 3.42 posi rear, not sure on the make, but I am sure the guys over at the suspension board can tell me so I don't infringe on anyone elses turf :P

Also, after reading everyones responses, I will definately be building this for boost, and with the forged lower end will possibly go for more boost than I had previously thought.

Oh, and to answer the question of if I will be pushing this car, I do intend to take it to the track a few times in it's lifetime.

 

MA has very strict CA type smog rules and regs, watchout, or be prepared to have is smogged by somebody that knows what they are doing (hand him $50-100).

 

stekman, rb, me leigh, everyone that posted here knows their stuff. i was in your situation not too long ago (right stek?) this is going to be a great foundation for you to start searching your but off and really figuring out where you want to go. trust me it will change

i made the mistake of buying a complete shortblock (which is a VERY nice shortblock) but i really wanted to turbocharge and cant now. so a second engine is in order when i get all the fun out of this one.

be prepared to spend a lot more than what you are planning now, seriously. there are so many nickel and dime things the novice doesnt know about its not funny . and when you start to learn more about what you want you will start to say "well if i just wait and save a little more i can get the afr heads in stead of the trickflows" (which i again wish i would have done)

to back up what they have said id go with a factory roller setup to make things simple and very compatible.
hydraulic roller cam etc. you wont be able to run as much lift because the hydraulic roller lifters are much heavier but you will learn about that later im sure.

if you want to go N/A try to get some sort of kit such as the hot cam kit (a very well rounded cam for approx 400 hp) that comes with almost everything you need. to save money comp magnum rockers would be well suited and as far as the bottom end get a stroker kit. that way you know everything works together and it does make it much more simple.
if you really want to go FI then a forged bottom end is a must. even if you dont need it now when the engine gets older and "slower" to other cars the bigger supercharger you want will blow the old bottom end to pieces.

after all that your basically left with the induction. im running a non emissions legal holley stealth ram and it is one of the best inductions for fuelie SBC's (when price is a factor). it is also incredibly easy to work on, gives a good power increase, and is very affordable compared to say the miniram (which is an amazing intake).
BUT since you say you want torque you might want to consider sticking with the TPI intake. some easy home porting of the intake and plenum and large sized runners will give you TONS of torque (what the TPI is known for) but also let you run to maybe 5000 rpm.

back to the suspension, drivetrain....prepare for a new torque arm etc to give the car much more traction and a Modified tranny (built to handle more power) and rear end will be needed or you will break them as soon as you do in fact get traction.
i have to stick with the junk t-5 and crappy 10 bolt for now but im prepared to face the consequences until i can afford things more capable to handle the power. the consequences being watching my right foot

just keep searching and learning. try not to make the mistake i did and buy parts you wont need or truly want. set you a goal and try to stay on track. for instance im running that bottom end that will give me 10.6:1 compression ratio. thats way too much for the turbo i want so i need a new bottom end. i have trickflow heads which are very nice heads but i really wanted the afr's and if i didnt rush i could have had a set for not too much more. and my 1 5/8 headers will be slightly too small but i went for the best priced headman headers at the time.

good luck youll love it!! when you start to get parts for the engine in you just become hooked for life!

 

Awesome, thanks. Everyone has brought up good points.

I think after reading, I am definately gonna build it for boost and later on down the road.. actually give it that boost. Having 400hp before the supercharger is my goal, and when I am in my late 20's with a full-time job I will probably turn the car into a full blown drag car and setup the supercharger.. or who knows, if I save well enough maybe sooner.

P.S. Will the hot cam kit work well if I want to add boost to it in the future, assuming I have a forged bottom end?

 

Hot cam is terrible for boost, you want at least 115 degrees of LSA for a boost cam.

 

Cams are cheap. If there's any one component that's specialized towards either N/A or boost, besides compression ratio, it's the cam.

When you "add" your blower "later", change the cam to one specifically designed for boost.

If you're building a N/A motor, gat a N/A cam. The LT4 HOT cam is OK sort of, but far from the best. Use it if you don't mind getting beat. See this thread. https://www.thirdgen.org/techbb2/sho...hreadid=273180

DON'T hallucinate that you can pick one that will work well with both. If you use a great "boost" cam in a N/A motor, you'll have a pig; use a great N/A cam in a boost motor, will limit what you can do with boost. Neither one works well in the other situation.

 

Ok, so one last question.. I think.

An engine setup for boost, with forged pistons, crank etc, and lower compression either via dished pistons or larger comb. chamber will not run well and/or will not create significant power (being a 383) without the supercharger?

Still trying to learn alot about this basic stuff before I dive into this boost or n/a decision.

 

Just go NA. This sounds like your first build. NA will be easier, make more than enough power, and there's a lot more knowledge at your disposal as to what combo to make. You'll have to spend enough money on an NA build anways. I second not going with hot cam. It's an ok cam but there are better options. Not to mention it will be too small for a 383. Oh yeah, and I would go with 1.75" primaries for a 383 boosted or not.

 

First off, someone said something about not being sure of the difference between a 5.7" and 6.0" rod...

Without getting into the technical side of this, let me put it like this; The longer the rod the less load placed on the cylinder wall and rotating assembly durring the compression/exhaust stroke. This leads to longer cylinder life, not to mention a decent boost in power due to the rotating assembly's ability to spin more freely.

This doesn't mean that no matter what you should pick the longer rod, in fact there's a certain stroke /rod length ratio you want to shoot for, this being 1.75:1, though anything 1.7:1 and above is good. This ratio looses it's cost effectiveness as you start to go above 1.75:1, so don't bother.

A 327 ci SBC has a PERFECT ratio of 1.75:1 with 5.7" rods, but a 350 needs 6.0" rods to even come close with a 1.72:1 ratio... This isn't ideal but it's still in the range of being GOOD. You can figure your ratio by dividing the rod length by the stroke:

For a 350 with 6.0" rods:
6.0 / 3.48 = 1.72

For a 327 with 5.7" rods:
5.7 / 3.25 = 1.75

Got it? Cool!

Now, this doesn't mean a 383 with 5.7" rods won't last a long time, it just means that a 350 with 6.0" rods will last longer. Don't bother trying to stuff 6.0" rods into a block with a 3.75" crank to get closer to 1.75:1 because in most cases it won't work, so don't even waste your time think'n about it, the closest you're gonna get without spending a fortune is 1.52:1, and that's with the 5.7" rods.

Back to the build... I read where someone said you should stick with a Naturally Aspirated (N/A) engine, and I must say that I agree whole heartedly! No offense but going Forced Induction (F/I) is kinda specialized. HOWEVER!!! You could try to build an engine that's as close to stock as possible while using tricks of the trade to free up some horsepower by making the engine more efficient. This is also a good idea do to the fact that noone (as far as I know) makes a blower kit for your year.

Here's a nice little 350 build that you might like that should pass smog without any issues:

- Blueprinted 350 block .030" over & "Zero-Decked" with a "Street Fill" and "Plugged Deck" (use ARP main studs too)
- 68cc AFR Comp Pkg 195's (L98 style)
- GMPP LT4 Hot cam (218/228 @.050", .492"/.492" Lift, 112 LSA)
- 1.6:1 Comp Cams Pro Magnum Roller Rockers (gives .525" Lift)
- Crower 4340 Forged Rotating Assembly (3.48" 1-piece RMS crank and 6" bushed rods) with JE Forged pistons (with floating pins and 1/16", 1/16", 3/16" ring lands)
- 9.75:1 Compression Ratio with FPP-1003 Head gaskets
- 30# injectors
- Adjustable F/P Regulator (play with it)
- ACCEL OE Style High Flow Plennum # 74189E, Runners # 74195, High Flow TPI Gasket Kit # 74195G, Base Manifold # 74197 and 1000 cfm Throttle Body # 74190

Did I leave anything out?

This combo would deffinately justify spending the money on a little computer reprogramming, and it'd be SO worth it!

You'd also want to upgrade the stock cooling system, and a new PERFORMANCE built tranny would be REQUIRED. I'd suggest a Stage 3 700R4 from http://www.BowtieOverdrives.com along with a 2500 Stall. You'd also want to have your rear end completely rebuilt with Richmond gears and an Eaton Posi (have the tubes welded too). 3.42's would be great! Don't waste your time trying to put a manual transmission in your car, that will be far more trouble that it's worth, trust me!

Exhaust wise, Hooker does make legal headers for your car, they're Part Number HOK-2055HKR (1-5/8" Shorty Style, 3" Y-pipe included) at http://www.SummitRacing.com. You'd want to back this up with a 3" High Flow Cat and Cat-Back system too. I like the Hooker Super Comp Cat Back System # 16823 myself, sounds damn good on these cars! It uses a 3" main pipe with dual 2.5" tail pipes/tips. Looks/sounds even better with larger tips, in the 3-3.5" range. I personally like the 35190's from Magnaflow... you can see them here: http://www.magnaflow.com/02product/tips/large.asp

Okay, I'm tired of typing. This is just my 2 cents, take it for what it's worth.

- Joel Penick

 

Since when doesn't a 3.75" stroke not work with a 6" rod?

No one makes a blower kit for his year? I guess that defies the many Supercharged TPI systems I have seen pictures from.

 

I'm not saying it CAN'T work, I'm saying that in most cases it doesn't, which means although it may fit, it's generally not a good idea. Basically, from the center of the wrist pin to the piston face would only be 1.125", which sounds like quite a bit until you factor in rod clearance on the piston's underside and the possible depth of valve reliefs in the piston's face. You can go this route if you like taking chances, but not me!

Damn this editing!

As far as I know most blower kits are for 88-92 Camaro's, I have yet to see any listed for 87 and under. I'm sure the kits can be modified, they may even be direct fit, but will the E.O. number still be valid? That's what I'm getting at.

 

As far as 6" rods for a 383 stroker, I am willing to bet more have than haven't.

 

i've got 6" eagle h-beams in my 383. the 1.52 rod ratio of the 5.7" rods didn't sound like a very good idea to me.

 

And just how many ponies are you push'n? How much torque you push'n at the same RPM as your peak HP? How high you revv'n? What's your CR like? How'd you get that compression ratio? How much clearancing did you have to do? Who's pistons are you runn'n?

 

Rod length and rod to stroke ratio plays very little part in power production. Dyno tests have proven it, the difference is nill. Infact in recent years some builders have built shorter rod motors for higher rpm.

It really only makes a difference in side loading and engine life, but even that difference is nill. Don't worry about it so much, it doesn't matter in the least.

 

6in rods for my 383. approx 490hp 490tq (465 ft lbs at peak hp, 5500 rpm) o yea then the 150 shot. 6200rpm. 10.6:1 CR. by running weisco 10.6:1 forged pistons (with a 2 valve relief). not anything outside of a stroker motor. weisco 10.6:1 forged pistons (with a 2 valve relief)...do i hear an echo?

 

you can check out my buildup in my signature. clearancing the block takes a bit with those rods. it's a good idea to epoxy the water jackets before doing so whereas there's a possibilty of breaking through. i built my engine to easily rev to 6500rpms because of the extensively ported superram but i also wanted to overbuild for safety's sake. i have not had it dynoed yet but i estimate at least 430-450hp and probably around 490 ft lbs at the flywheel. be prepared to spend a whole lot of money if you're building a revver and don't scrimp on machine work.

 

true, rod length has very little effect on power output, but side loading is never a good thing. since you're buying rods anyway and you can choose between a longer rod or a shorter one, why not just go with the longer one?

 

Nice builds guys! Very impressive I personally wouldn't chance it but you guys have and to you I say congrats! I wish you the best, hopefully no mishaps take place due to the shortness of those pistons, that would truely be a shame.

I've done some extensive dyno testing myself concerning rod length and power output, and to be honest, when the rods are within a half an inch of eachother you'll barely see any difference on a dyno... The longer rods tend to show a bit more top end and the shorter ones tend to show a bit more low end, but still not that much.

My main point behind the rod length issue is longevity! I like to build high powered engines that are both versatile and long lived. I like engines that can take a beating without worry.

Okay, enough about that, we can all agree to disagree here.

The reason I suggest just go'n with a 350 is that it's gonna be alot easier and a fair bit cheaper, which is a good thing if/when it's your first REAL build. True, a 383 would give you better mileage at low RPM's due to the torque increase, but when you're tach'n her out like I expect you will, you'll get way more fun time out of the 350. Just a thought. Like I said, that was all just my opinion, take it for what it's worth.

You said you're do'n alot of learn'n via books... I've gotta give you props on this cause it shows you're serious. This also gives you a leg up on your competition (other young guys) who are gonna just throw on a bunch of big numbered expensive items. True, this will most likely increase their power output but not as much as a well tuned parts-matched engine like you're gonna build.

No, I'm not bash'n on the young bloods cause I'm one myself (24), I'm just stating a fact! Most young guys don't have a clue what parts matching REALLY means. Even fewer know how to build an engine, most barely have an idea on how to assemble one!

Anyhow...

Lingenfelter is an amazing man, but don't forget to read up on books from Smokey Yunick (R.I.P.) and David Vizard aswell. Most of these can be found on Amazon.com at a nice price.

I don't know if anyone's asked this but are you building this thing to meet your local smog requirements? I assumed you were since someone said your smog laws are as bad as the ones in Cali (where I live). Are they testing on the dyno out there? They are here!

So what you think'n thus far?

Good luck!

- Joel Penick

 

I did a fair amount of book reading early on. TGO is infinitely more useful.

 

I thought that went without saying... Guess I was wrong. Well, as long as we're mentioning useful websites on the topic, you might wanna check out http://www.NastyZ28.com

I have learned a TON from these guys over the years.

- Joel Penick

 

"but when you're tach'n her out like I expect you will, you'll get way more fun time out of the 350."

What kind of redline does a 383 have? I don't really push my current engine rpm wise. I just like to accelerate quickly then let off on or around speed limit or whenever the person in the next lane is sufficiently behind.

 

Thanks... Good Stuff

 

I'm also in the learning position, I bought this book off amazon.ca

 

Good book, but the focus is too heavy on ultra high CR race motors and old school SBC's. Not too useful for a thirdgen motor build.

 

Eagle and Scat crankshafts are usually cast nor forged, they are ground from a solid block. That is how they are stronger than a cast factory crank. A 4340 crank is only needed if you plan on going supercharged or Nos for sure. If not it is an expensive that is harder to justify. Fuel injected or carbed makes no difference on the crank selection.

Hydralic roller cams are better than a flat tappet. But the cost of flat tappets and solid flat tappets is sometimes $hundreds$ less. Unless you are going for all out power, flat tappet is fine.

Why would he get more fun out of a 350 with 6" rods than a 383 with the 5.7" rods?

 

Though I agree with you about the cost difference between F/T and Roller cams / componnents, this doesn't seem to be much of a factor here. If he's saying he wants Brodix heads and such, and he's say'n this will be a long term project, I say build it the best you can. And Roller cams aren't just for race, if that was the case they wouldn't use em in every new car on the road today, the fact is you can get better OVER ALL performance out of a Roller cam than you can a F/T cam. The other reason I suggest a Roller cam is because of it's longevity, since a Roller cam is so much SAFER to run and sees so much less friction.

Quality cast cranks are often more than enough, and in this case that may be true... Like I said, I like to build engines that can be beat on without worry. But like you said, if he's to put N2O on this engine then a Forged crank is a must.

You missed a key word in quoting me about getting more fun TIME out of a 350 than a 383, that word being TIME. I simply meant that the 350 will have a longer lifespan when being beat on due to harmonics and side load, and due to fewer cubic inches and a more "efficent" rotating assembly, it should get better mileage too.

As far as more fun power wise... "There's no replacement for displacement."

Apok,

You asked about the redlines of these engines... Generally a 350 will have 500-1000 more usable RPM. Most 383's will pull hard to around 4000-4500 RPM but fall off quickly after this, while a similarly built 350, though it may not pull as hard up to around 3500 RPM, will still have quite a bit of pulling power after the 383's begin'n to fall off.

It's all about figuring out what you need and building to meet those needs. So though it's late in the thread I've gotta ask, what EXACTLY do you want out of this engine? What type of driving do you want to do with this car once you have the new engine? Is mileage a concern?

Take care Y'all!

- Joel Penick

 

depends pretty much on your cam, intake, valvetrain and head choice. a fully forged 383 with rev kit, splayed mains and arp studs will safely rev and hold power WAY higher than that as long as it can breathe. check out the miniram/stealthram guys revving them to 6500 and beyond.

 

That's exactly why I said MOST The majority of 383's out there are budget builds, therefore the chances of them pulling much past 4000-4500 RPM's is slim. Also keep in mind that I'm not saying they won't rev higher than 4000-4500 RPM, I'm just pointing out that they tend to stop pulling as hard at higher RPM's while 350's tend to keep pulling hard till they hit around 5000-5500 RPM. Once again, I'm referring to budget builds, ofcourse aftermarket parts will push these numbers higher, but the difference in powerband will tend to remain.

 

Agreed, but would you be able to tell a real difference between a 350 with 6" rods and one with 5.7" rods?

 

Depends on what you mean by a difference. My experience has been that with the same stroke, two rods within .500" of eachother will show little if any difference on a dyno, assuming the rod/stroke ratio is somewhat decent to begin with. Now, as the rod/stroke ratio decreases, the difference will become more and more noticable, especially at higher RPM's, but it still won't show up much on a dyno... Oh, it'll show up on a dyno alright, there just won't be any HUGE difference.

The difference you will notice is how much smoother the engine seems to run, the slight increase in throttle response, the engine's willingness to rev higher and when it comes time to rebuild the engine, you'll notice less cylinder wear. This decrease in cylinder wear is taken even further when a street fill is utilized.

Running longer rods serves another purpose too... Aside from decreased cylinder wear and all that, running longer rods will often allow you to get away with a less expensive crankshaft. This is because of the decrease in sideloading, which puts added pressure on the crank. Once again, this becomes more and more true the further the rod/stroke ratio falls below 1.75:1. Running a 1-8-7-2-6-5-4-3 firing order will have much the same affect by itself, or have an even greater affect when matched up with the longer rods.

These are all principals I use when building engines, but that's me, y'all do what you think is best. I'm just share'n my own experiences, hope they help.

- Joel Penick

 

You have been incredibly helpful Penix, as well as everyone else that has posted.

Since you asked, I would like it to be pretty much a daily driver that can do 1/4 mile drag passes in the low 13's to high 12's. Mileage isn't really a concern, although I'd like for it to be close to 12/13 mpg. I am around 17-18 right now with my 305, and I don't mind takin a dip if it means alot more power and just more fun out of the car.

As well as the things I have talked about here, I will be doing some weight reduction to the car this coming summer along with the suspension work that I should be getting done very soon. I am hoping to trim close to 200 off the car, but we shall see.

Anyways, I hope this has given you enough information. I really appreciate everyones willingness to help me on this subject. It has already helped to solidify lots of my knowledge on these great little engines us 3rd gen'ers love so much

 

Sounds to me like a blower would be your best bet, but as stated, you can't really build a N/A engine then boost it. So I'd say go with the next best thing and get a N2O kit for it. What type of kit is up to you ofcourse, but a well built 350 with something along the lines of a 150 shot should push you well into your 1/4 mile goal.

A 383 would do this aswell, a bit easier too in fact, but the combination of a 383 and N2O would be a bit harder on parts and wouldn't get as good mileage, which isn't the best idea when it comes to a daily driver.

My vote is still for the 350 with N2O... A CSC (Cent. Supercharger) would be cheaper in the long run and a bit easier on parts, but that would take building the engine around the CSC, which would mean it'd be lacking (quite badly) before the blower was installed. If you wouldn't be able to install the blower till later, this would be a bad idea... UNLESS!!! If you were to get a two-piece timing cover that would allow you to easily remove the cam, along with pop-up lifters, you could rather easily run one cam while the engine was N/A then switch to a different cam once it was blown, assuming you have enough room to remove/install a cam with the engine in the car. The only thing that would suck about this is that you'd be limited to a compression ratio of between 9 and 9.2:1 (Safely). This would limit power output potential both N/A and blown, so once again, that kinda sucks.

Whatcha think'n so far?

 

Wellll.. I really wanna go with a 383 n/a. That is my first choice

 

well it doesnt sound like he's talking about a budget build. those brodix heads and superram will be happy rev to 6300 no problem.

do it. you won't regret it. just clearance it so you can hit it with nitrous later on (you know you will...)

 

I don't think you fully read the quote that you used... At the end of it I pointed out that aftermarket parts will push those numbers up, in other words, the engine will produce power at higher RPM's that it would stock. The point I was trying to make is that a comparably built 350 will have about 500-1000 more usable RPM, that's all.

Okay, so you're stick'n with the 383 idea, good for you.

If you're go'n this route then for your own sake be sure to street fill the block, "plug" the deck too while you're at it. Your machine shop should know exactly what you're talk'n about when you mention these procedures. The "plugging" of the deck is when you tap the water jacket holes then screw in a pipe plug and drill a much smaller hole in the middle of it. This strengthens the deck and upper portion of the cylinders quite a bit. Doing a "street fill" is when you turn the engine on one side so that the deck is PERFECTLY level, both front to back and left to right, then use a block filler like Hard Blok to fill the water jackets up to the bottom of the freeze plugs. Some block fillers require you to let the block sit for DAYS, nearly a week in some cases, before you can turn the block over and do the other side, with Hard Block you can generally do this within 24 hours of pouring the first side. This strengthens the lower part of the cylinders (which are affected most by side loading) and has little if any effect on cooling

These procedures would be the first to be carried out after the block is cleaned (by whatever means the shop uses). I like to have blocks hot tanked, then magnafluxed, then shot peened. Same goes for old cast iron heads.

As for rods, I personally wouldn't go any longer than a 5.850" rod. This still gives you slightly over an 1-1/4" compression height, which is still safe enough to use with N2O or boost. The only problems with this size rod is that you will have to custom order the rods and pistons and clearancing will most likely have to be done. Can get rather expensive.

Okay, well I've got alot still left to do today so I'm out for now.

Late

- Joel Penick

 

Awesome advice, the machining stuff was exactly what I was looking for. I have decided over the course of this thread that if I'm going to do a build, it's going to be a 383 that makes it's power all motor and no forced induction or anything else of the sort. I might do it on another car in the future, but my first will be this way. As far as the rods, I don't think I will ever hit it with N2O, so 5.7 inch rods are fine with me. Although a small and relatively un-noticeable problem (until something breaks/cracks), sideloading doesn't sound like something I want to have in excess. Does this sound about right or is there something I am missing.

 

Sounds like you got it right, but just incase... The longer the rod the less side loading you will encounter.

Having said that, the effect of sideloading on the cylinders can be reduced a fair bit with the "street fill". I personally would spend the extra money on the 5.850" rods and matching pistons, but that's me, if you're wanting to stick to a smaller budget then the 5.7's will do fine. Still, do some price checking, see how much the cost difference will be. Just don't forget to get matching pistons.

I tend to run crower cranks and rods with JE pistons in custom applications like these. Crower is compeditively priced with top notch quality, and they're quick too! Same goes for JE, and since JE and Crower work together you have parts that are pre fit.

Oh yeah, if you chose to go with a 1-8-7-2-6-5-4-3 cam, deffinately go through Crower, they've got the best prices on these custom cams.

This help any?

 

Ohhh, I thought it was the longer the rod, the shorter the piston, and the more side loading, nevermind :P

 

The longer the rod, the shorter the piston, but with less side loading.

You can figure how tall your piston will be like this:

Deck Height - (Stroke / 2) - Rod Length = Piston Height

or

9.000" - (3.750" / 2 = 1.875") - 5.850" = 1.275"

Like I said, I personally don't like building engine's with pistons shorter than 1.250", but many have and if you feel up to it feel free. But yeah, the longer the rod the less side loading you will encounter, but the shorter your piston will be. Idealy you want to find a happy medium.

Just to make sure you understand the formula...

With a 350 and 6.000" rods:

9.000" - (3.480" / 2 = 1.740") - 6.000" = 1.260"

Make'n a bit more sense?

I'm out, gotta replace the tranny in my friend's RSX-S... Damn imports!

- Joel Penick