383 Combo Going to Builder

murrayo · Apr 14, 2006

Hello All,

I have finally started talking with my engine builder. After reviewing all the articles in this forum, on the web and all the rags, I came up with this combo. My goal is the have a mild 383 with tons of torque.

My Builder swears buy the Scat Rotating assemblies. He was looking at the assembly with 6 inch rods and the KB Hyper -19cc dished pistons. That will be interally balanced and they always go over them to check.

From there the motor will look like this:

383 bottom end
IK180 Brodix heads
Comp Cams 4x4x4262H Cam (Duration 262/ 270, Lift .462/ .480 )
Intake is Professional Products Cross winds ( Air Gap knockoff )
Holley 650 Spreadbore Vac. Sec.
Roller Rockers 1.5
Borla 1 5/8 headers
2.25 Exhaust...Hooker Aero Chambers

Since his dyno is down, I'm not sure what this will put out for power. I may help him get the dyno up selfishly for me.

Let me know

Timo

rlovell383 · Apr 14, 2006

The grey matter dyno tells me 440 ft lbs and 420 hp at around 5500 RPM.
Have fun with it!!!

Randy

CNC BLOCKS N/E · Apr 14, 2006

Here is a a link to one we did last summer for a customer and we just dyno ed one with Vortec heads a month ago with same on on a 110 lobe sep. as the custmer wanted a not so choppy idle and it made 488 torque and 449 horse and the one in the link had a 108 lobe sep.

This will give a good idea what can be done and what we used.
http://www.chevelles.com/forums/showthread.php?t=106715&highlight=DYNO

JimM · Apr 14, 2006

You might consider going with a forges SRP piston rather than the K-B's, much better / stronger product, and not much more $$$

murrayo · Apr 14, 2006

Looks like the Forged SRP is $250 more. The KB forged is only $120 more. Are the SRP that much better? I'm not going to race this or every add nitrous to the car. I thought the Hypers would be ok.

JimM · Apr 14, 2006

I'm surprised Carl kept quiet on this, but popular wisdon here seems to be stay away from hypers, especially K-B's.

The K-B's require a much larger than normal top ring gap.

A recent hot rod mag (not the one that just came out, the one before that) did a thing on "why did this engine destroy itself" one or 2 of the K-B hypers in it had shattered like glass!

Eric68 · Apr 14, 2006

I agree, while there are lots of K-B pistons out there working just fine, I personally do not like them. If you can spare the extra cash pistons is a good place to spend the money.

Several years ago I broke a K-B piston ring land when they were recommending about .026" top ring gap. Now they are saying more like .030 for the top ring. I have since switched to SRPs and have done fine with .019" top ring gap.

If you never have any tuning or detonation issues the K-B pistons will be just fine, personally, I like living on the edge and cast or hyperutectic pistons are not very forgiving when step over the line with them.

JMO

sschevellefan · Apr 14, 2006

I ran KB domes in my old 327 with no problems. I even ran them in a Harley Davidson motor I built with no problems. They would be fine for a mild street set up like yours. I know several people who have run them, one was a 12.1 383 that ran mid 10`s. Some guys used NOS on them with no problems. Your going to find people you like them and people who hate them. I`ve seen alot of engines built using them and none of them have lost a piston. I`ve never seena motor go because it had Kb`s in them. not saying it won`t happen, just haven`t seen one yet in my experience. I considered running them in the 377 I`m bulding now but I thought I might want to add NOS later so I found some Ross forged flat tops for a good price. If it was a street/mild strip motor I would run the KB`s again.

67 Plum · Apr 14, 2006

If you want Hypers use Speed Pro alot better than the KBs.JMO

Motorhead62 · Apr 14, 2006

Timo,

Why are you going to top off a great set of heads with an el cheapo, knock off intake manifold?

That cam is going to be too small. I would go one size bigger IMO.

Good Luck

CNC BLOCKS N/E · Apr 15, 2006

JimM said:
I'm surprised Carl kept quiet on this, but popular wisdon here seems to be stay away from hypers, especially K-B's.

The K-B's require a much larger than normal top ring gap.

A recent hot rod mag (not the one that just came out, the one before that) did a thing on "why did this engine destroy itself" one or 2 of the K-B hypers in it had shattered like glass!

Well here we go at our shop we are known to build quality engines that perform well and have no problems and if we are going to spend the time to build a quality engine we don't use Hyper pistons or cast cranks.

We balance alot of cranks for other shops and to drill a forged crank takes some effort and to drill a cast crank is like cutting through butter as the forged cranks have nitrided surfaces and the cast cranks have soft surfaces.

And no matter how you look at it the Hypers are still a cast piston.

And I agree the cam is kind of small for that application

rlovell383 · Apr 15, 2006

I agree forged pistons and forged cranks rule. No doubting they are stronger. However the reality is that there are those of us who cant afford the best parts and have to make do with what we have. We want the most speed for the least money. I believe thats one trait that characterizes a true hot rodder. I PROMISE you that properly built, a cast cranked, hypertech pistoned, el-cheapo bottom end with a no-name intake will survive his mild 400 horse street build up. There are definatly limits to these parts and he is well within them. I bet he would smile even more knowing he just spanked the guy in the other lane knowing he didnt shovel money at his ride. Sorry for the rant it must be late.
And I also agree the cam pick is small.

Randy

Motorhead62 · Apr 15, 2006

And one other thing, you need at least a 2 1/2" exhaust. Don't try to think the smaller pipes will add torque, not true!

murrayo · Apr 15, 2006

At this time, things that are not going to change will be the exhaust/headers and the Intake unless it has some issue. The Cam is still up in the air. I was also looking at the Comp X4 270H-11 which has a spec of .480 /.498 lift with 226/234 Duration and a 111 Lode separation. I don't think I want to go any larger than that.

The Forged pistons my be cheap insurance and I am going to inquire about the forged crank. I think that assembly would be around as long as my current 327 ( 18 years ).

Timo

383 Combo Going to Builder

murrayo

rlovell383

CNC BLOCKS N/E

JimM

murrayo

JimM

Eric68

sschevellefan

67 Plum

Motorhead62

CNC BLOCKS N/E

rlovell383

Motorhead62

murrayo

Top Contributors this Month

Recommended Communities