383 setup

[zraffz]

I have my mind set up on my top end since I already have the heads although I wish I had gotten a set of AFRs. I will be running Trick Flow Super 23 195cc aluminum heads and a 242/248 (294/300) duration .540"/.562" lift 110 LSA roller cam.
Motor should shift around 6,500-6,600 RPM and be set up for a 100 shot of nitrous. Car will see less than 1,000 miles a year, weighs about 3,200lbs with me in it, 4.10s, trans braked th400 and will maybe see 10-20lbs of nitrous a year max. I'm hoping for about 400whp in the car without the nitrous.

I currently have $1,600 set aside for a bottom end; or at least a good chunk the bottom end. I have a 750cfm holley 4 barrel, the heads, the intake manifold, the long tubes, the distributor and other small parts.


I am looking into a Summit pre-machined 355/383 block for the ease of things although I don't mind having to do the final cut on the bores.
http://www.summitracing.com/parts/sum-150100

I'm a little up in the air about running a cast crank although I don't think I'd have any issues. One question, how can a crank be good for a 5.7" rod or 6" rod like this one is claiming?
http://www.summitracing.com/parts/sca-935050l

Being 62cc heads and me wanting to keep my compression as close to detonating on 93 octane as possible without milling brand new heads I chose forged Wiseco 13cc dished pistons with 1/16 plasma moly rings.
http://www.summitracing.com/parts/wi...make/chevrolet


I have concerns about h-beams clearing, yet these aren't weight matched and I don't know if I am over thinking things or not. Not weight matched or balanced but they are supposively clearanced.
http://www.summitracing.com/parts/cpi-a6000ds2a2ah

These are i-beams, rated for 550+ HP, lighter weight, weight matched (not balanced) but do not have any stroker clearancing.
http://www.summitracing.com/parts/man-14103-8

I've never been a fan of SCAT rods because of the bolt design and it being a pain to take back apart once it's on the crank but these seem too good to be true. Clearanced, matched and balanced.
http://www.summitracing.com/parts/sc...1qls/overview/



PLEASE HELP lol. I feel like I am seriously over thinking things and it's driving me insane.

[LTb1ow]

Why would a crank care if your rod is 5.7 or 6.0? The piston will care.

[Featherburner]

Originally Posted by zraffz

I'm a little up in the air about running a cast crank although I don't think I'd have any issues. One question, how can a crank be good for a 5.7" rod or 6" rod like this one is claiming?
http://www.summitracing.com/parts/sca-935050l

The crank doesn't care what rods are swinging from it but the pistons do.

[zraffz]

Most cranks are advertised as a specific length rod. No idea why but I always figured it had something to do with it. I understand why the pistons would need to be set for a specific length rod.
Thanks for clearing that up guys.

[JSPERFORMANCE]

Originally Posted by zraffz

Most cranks are advertised as a specific length rod. No idea why but I always figured it had something to do with it. I understand why the pistons would need to be set for a specific length rod.
Thanks for clearing that up guys.

Balancing & counterwieght size..

[LTb1ow]

Just to be philosophical... why run a cast crank with forged $600 compstar rods..?

[zraffz]

Originally Posted by LTb1ow

Just to be philosophical... why run a cast crank with forged $600 compstar rods..?

Cause I don't know what I need. Pretty much the reason for this topic. I'm asking if my parts are worth buying or not.

I understand it's not your money so it's easy to suggest a $1,000 crankshaft, $1,300 rods and what not but this is about reliability for the money I spend and the power level I am looking to achieve.

[sweetbmxrider]

He's saying you are using good budget rods on a **** crank.

[LTb1ow]

Originally Posted by sweetbmxrider

He's saying you are using good budget rods on a **** crank.

Yarly.

No sense in have 700hp rated rods on a 500hp rated crank.

[zraffz]

Originally Posted by LTb1ow

Yarly.

No sense in have 700hp rated rods on a 500hp rated crank.

Have seen many ten and eleven second cars at the track running cast cranks. Really, even online the only times I've heard of a crank getting destroyed was with forced induction but yet I've seen rods snap in half on higher rpm motors.

[LTb1ow]

Originally Posted by zraffz

Have seen many ten and eleven second cars at the track running cast cranks. Really, even online the only times I've heard of a crank getting destroyed was with forced induction but yet I've seen rods snap in half on higher rpm motors.

I am not saying you are wrong, just questioning the pricey rods on a cheap crank.

Granted I am coming from LT1 land, which is mainly dumb people, but cast cranks seem to snap frequently IF they do not get the correct prep work by machine shop. And its not just FI builds, I have seen a few NA builds snap em as well. Comes down to home much money you wanna spend on top of crank cost to get em balanced well and in tolerance for assembly.

Just to clarify, its not assuming casts are bad, just stereotyping that they are cheap due to lack of QC.

And for the pricey, high HP rods, you are throwing some serious weight on a cast crank, I am no expert but assume thats part of the puzzle here to be considered. From LT1 land, stock rods are fine to past 6500 area, but the rod bolts are weak and allow bearings to spin. So a cheaper I rod with quality L2000 or whatever the ARP kind of rod bolt in em may work better.

Take it as you will.

[Blackbirdws6]

Weigh the time it would take save the $$ to put in decently better parts all around versus the time it would take to rebuild it if something went wrong. You don't need really pricey parts but a solid forged and properly put together bottom end will last you a while. You can also spray it without much concern. For a few hundred more, a forged steel crank will be worth it in the long run.

http://www.summitracing.com/parts/es...make/chevrolet

[sweetbmxrider]

But then you should spend more money to begin with because the eagle cranks take more mallory to balance which comes very close, if not exceeding, the cost of a compstar, ohio, or the like crank.

[Paul Huryk]

You should be able to push out 500 to 525 engine hp with your motor with that setup of heads and cam.

[zraffz]

Originally Posted by Paul Huryk

You should be able to push out 500 to 525 engine hp with your motor with that setup of heads and cam.

You really think so? I was honestly expecting to be around 460-480 crank. Obviously wouldn't complain if I made more though

Anybody know anything about the company Ohio Crank? They have the crank I need for $495. Maybe a stupid rookie question but what determines if a crank is going to be internally or externally balanced before the balancing process occurs? (I ask because ohio crank doesn't specify and I would prefer an internal/neutral setup like I am familiar with).

You guys make a valid point. I'd rather do it right the first time and be able to trust what I built.


Edit:
And how are these rods? They are balanced, clearanced and weight matched.
http://www.summitracing.com/parts/sc...1qls/overview/

[Paul Huryk]

Originally Posted by zraffz

You really think so? I was honestly expecting to be around 460-480 crank. Obviously wouldn't complain if I made more though

Anybody know anything about the company Ohio Crank? They have the crank I need for $495. Maybe a stupid rookie question but what determines if a crank is going to be internally or externally balanced before the balancing process occurs? (I ask because ohio crank doesn't specify and I would prefer an internal/neutral setup like I am familiar with).

You guys make a valid point. I'd rather do it right the first time and be able to trust what I built.


Edit:
And how are these rods? They are balanced, clearanced and weight matched.
http://www.summitracing.com/parts/sc...1qls/overview/

Well, I checked out a 383 that Lingenfelter built and is in his book "JL builds SBC engines" and a similar setup put out 493hp at 6000rpm with a carb. Now your heads flow a little better and your cam is one step up, so I would think that if perfectly tuned it would be over 500hp.

Either you leave what you have (maybe change bearings, bolts, and oil pump) or you build it right with a solid bottom end - no reason to do things half way... And then have to do it again.

[LTb1ow]

Originally Posted by zraffz

You really think so? I was honestly expecting to be around 460-480 crank. Obviously wouldn't complain if I made more though

Anybody know anything about the company Ohio Crank? They have the crank I need for $495. Maybe a stupid rookie question but what determines if a crank is going to be internally or externally balanced before the balancing process occurs? (I ask because ohio crank doesn't specify and I would prefer an internal/neutral setup like I am familiar with).

You guys make a valid point. I'd rather do it right the first time and be able to trust what I built.


Edit:
And how are these rods? They are balanced, clearanced and weight matched.
http://www.summitracing.com/parts/sc...1qls/overview/

I believe Adam was looking at Ohio cranks before settling on a compstar piece.

Internal vs external is gonna be a big debate and it comes down to how much money you wanna spend. I assume that a crank will come close to balanced if they claim its neutral but again, it pays to have a shop check it out.

Internal will have the crank drilled to accept heavy metal slugs and the shortblock will be "modular" in the sense that the flexplate is not paired to it. However, depending on how off the crank is balance wise, it can be fairly expensive at ~$70 or so a pop of heavy metal.

External takes the balance weight and throws it on the flexplate or flywheel instead on internally. Cheaper, and simple, BUT it means you are stuck with the flexplate to that engine. So switch to a larger/smaller torque converter or trash the flexplate and you may be up ****s creek until you can make another flexplate with the exact weight used previously.

I believe in terms of engine performance, a fancy internal balance is recommended as it does not allow the crank to oscillate as bad on the mains at high RPM. I am not 100% on that, and is something you gotta discuss with your machine shop. I chose to be cheap and just keep my longblock externally balanced, machine shop said for most street type builds you won't be able to tell the difference.

Edit: Feel stupid now, didn't read your question, misinterpreted thought you asked internal vs external, and don't feel like deleting

[zraffz]

Originally Posted by Paul Huryk

Well, I checked out a 383 that Lingenfelter built and is in his book "JL builds SBC engines" and a similar setup put out 493hp at 6000rpm with a carb. Now your heads flow a little better and your cam is one step up, so I would think that if perfectly tuned it would be over 500hp.

Either you leave what you have (maybe change bearings, bolts, and oil pump) or you build it right with a solid bottom end - no reason to do things half way... And then have to do it again.

I'd bet on a stripped down engine dyno this combination could do 520 horses with a good tune. I have a tendency to think crank horsepower as fully dressed through mufflers and full accessories like how new cars are rated. I don't doubt this is a 460-480 hp motor with that rating.

[Paul Huryk]

Originally Posted by zraffz

I'd bet on a stripped down engine dyno this combination could do 520 horses with a good tune. I have a tendency to think crank horsepower as fully dressed through mufflers and full accessories like how new cars are rated. I don't doubt this is a 460-480 hp motor with that rating.

I'll re-read the article tomorrow to see if the accessories were attached. You must be thinking about the 60's and early 70's factory ratings that were without any accessories and fully tuned - production cars rated at 300hp ran more like 225 on the street...

[zraffz]

Originally Posted by Paul Huryk

I'll re-read the article tomorrow to see if the accessories were attached. You must be thinking about the 60's and early 70's factory ratings that were without any accessories and fully tuned - production cars rated at 300hp ran more like 225 on the street...

Exactly what I am thinking. I thought most crate motors were dynoed without accessories and I know most magazine articles publish pictures on the dyno without accessories to boast larger HP gains than what they truely have.

[Paul Huryk]

Originally Posted by zraffz

Exactly what I am thinking. I thought most crate motors were dynoed without accessories and I know most magazine articles publish pictures on the dyno without accessories to boast larger HP gains than what they truely have.

Doesnt say if there are accessories on the motor:

350 block
400 cast crank
5.7" rods
10.5 compression
Comp cams solid roller: 236 @0.050" - .587" lift
750 holley
Ported aluminum L98 heads
1.6 roller rockers
Victor Jr intake
1-3/4" headers

489hp at 6000
478 TQ at 5000

This motor obviously doesn't require a solid roller since it only revs to 6500, plus the heads are limited to about 260cfm flow - although they are super high velocity ports.

[WildBillyT]

Originally Posted by zraffz

Exactly what I am thinking. I thought most crate motors were dynoed without accessories and I know most magazine articles publish pictures on the dyno without accessories to boast larger HP gains than what they truely have.

I thought they were. As installed in a vehicle, SAE net.

Of the guys I know with crates who had post-purchase dynos done, all of them made more than rated by a few hp.

[zraffz]

Originally Posted by Paul Huryk

Doesnt say if there are accessories on the motor:
489hp at 6000
478 TQ at 5000
This motor obviously doesn't require a solid roller since it only revs to 6500, plus the heads are limited to about 260cfm flow - although they are super high velocity ports.

My heads might flow right around that and but my cam is a bit more agressive. Guess I'll never know for sure but I'm more interested in what it will run more than anything.

Originally Posted by WildBillyT

I thought they were. As installed in a vehicle, SAE net.

Can't really believe crate motors are rated that way. I've seen quiet a few boasting larger numbers than I could really believe possible with the top end they had. I think companies like GMP rate them SAE net but most don't.

For instance they rate a stock rebuilt LT1 long block at 330HP/350TQ in Summit.

[WildBillyT]

Originally Posted by zraffz

My heads might flow right around that and but my cam is a bit more agressive. Guess I'll never know for sure but I'm more interested in what it will run more than anything.




Can't really believe crate motors are rated that way. I've seen quiet a few boasting larger numbers than I could really believe possible with the top end they had. I think companies like GMP rate them SAE net but most don't.

For instance they rate a stock rebuilt LT1 long block at 330HP/350TQ in Summit.

Do you have a link? I can't find it.

Regarding crate engines, this dude knows his stuff cold:

Originally Posted by Damon at NastyZ

GMPP crate motors are rated the same way they do for production line engines. It's SAE NET at the flywheel. However, the CONFIGURATION of the motor as-tested is not necessarily the same as a production line engine.

In a production line engine HP is rated "as installed" with all accessories, full factory exhaust system, factory air box, etc. Since a crate motor will have unknown as-installed configuration, they sorta "pick and choose" the configuration of the engine for the test. In the case of the popular 260HP 350 they chose headers, high flow exhaust, aftermarket dual plane intake, 4bbl carb, low-restriction air cleaner with few front end accessories (just water pump, I think) and, of course, tuning optimized for power.

That's why that engine (a veritable clone of the LM1 in a late 80s Z28) is rated much higher than the factory installed engine was. The factory installed engine had cast iron manifolds, single exhaust, cat converter, factory cast iron intake with a QJet topped by a quiet air cleaner assembly and a bunch of emissions equipment along with a full complement of front end accessories. Tuning was also designed to meet emissions, not necessarily maximize HP. That's a lot of differences.

Please note that "260 HP" crate engine has been rated at 195, 205, 225 and 250HP over the years. The engine has been almost unchanged since the 1980s, however. Only the rating has changed and only becuase GM used different configurations for the testing. More conservative in the past, more liberal in recent times. That "260 HP" engine is the one that GM has most stretched the believability of the rating.

However, almost every other crate motor GM just carries over the production line HP rating to the equivalent crate motor. Which means if you slap some headers on them and a free flowing intake system they often put out considerably more power than their official rating.

LAST DIFFERENCE...... Only the mother ship consistently rates using SAE numbers. Just about everything aftermarket is quoted in STP (Standard Temp and Pressure) numbers. SAE is more "stingy" while STP is more "liberal". You can imagine why the aftermarket would tend to gravitate to the more "liberal" STP numbers- it makes for higher power numbers which is good for business.

All I could find was this at Jeg's:

http://www.jegs.com/i/Blueprint-Engi...5029C/10002/-1

[zraffz]

Originally Posted by WildBillyT

Do you have a link? I can't find it.

Regarding crate engines, this dude knows his stuff cold:



All I could find was this at Jeg's:

http://www.jegs.com/i/Blueprint-Engi...5029C/10002/-1

Interesting read, and I guess I was incorrect it was indeed made by Blue Print not GMP and made 300 horse. (Still, varies from GM's rating).

I'm certain those are the specs cause I remember it was awfully close to one of the motors I built with a hair less cam than I had and I didn't expect anywhere near those numbers.

Damn I wish I could find the one that really stuck out. I believe it was Blue Print that rated a 350 with vortec heads and a 220/224? duration cam at like 405 HP. I kinda just assumed that was not an SAE dyno cause it seemed quiet high.