18' vs. SB2.2

[Goa'uld]

Any thoughts on the comparison between a 380-388 18' and the same cu.in. but with SB2.2 heads? Am looking to either build or purchase an open motor this winter and was wondering which package to go with.

[pms]

SB2.2. I too will be purchasing a open motor this winter and from all the info I have picked up from Bill Hendrens and others I feel that it is a no brainer! Hopefully a few SB2.2 users will chime in on this one.

[Thick55]

Our 18 degree will outrun our sb2.2 and its a smaller cubic Inch motor

[Jimmy Judd]

There really is no comparrison between the 2. A propperly built SB2.2 is to what the 18's were to the 23's

My Hendrens 407 Sb2.2 absolutley killed much larger CI 18's (420-430) when there was traction. If you run in an area or at a track that is dry slick from the get go, you definetly need to choose your combination carefully..

Just to give you an idea, one thing to note, I found my self running a gear that was 75-100 points taller then the 18deg 400 - 430's yet still running at the same rpm 8400. The TQ was huge and never seemed to quit un like the 18 stuff just past the flag stand. My biggest problem has been getting her wooed up (taller gear) in time to enter the corner from being so much faster down the shoots.

Other then over driving entry, The only other difficulty with the pig, was getting use to easing into the gas on starts and re starts with out blowing the tires away. On mine, max TQ was at about 4600 and then flat lined to about 7400, only to fall off 50 ft lbs or so at 8600 So as soon as you stomped the loud pedal, it was there. A good 18 will hit hard out of the shoot with good TQ #'s but will fall way short from the flag stand on. The 18 I am referring to was a good friends 421. All though his TQ did reach its max a few hundred RPM sooner then mine, Its max TQ was only 20 or so less then mine. The big difference was where the TQ finished. His motor finished out @ 390-400 ft lbs @ 78-8000, where mine was well over 580 at the same RPM

18's have there place, and some can and will make due.

If you are going to build an SB2.2, Make sure you can trust your builder to arrange the correct combination, bore/stroke, compression, series head, matching intake, cam, and rocker ratio... Many don't have a clue as to what it takes when just slapping a bunch of various used (auction) cup parts together. There is lots of SB2 stuff out there to be had cheep, Stay away from this stuff as they will not make the desired power or TQ needed for a dirt late model.. There is a night and day difference between an SB2 and a SB2.2

fwiw

My #'s were
HP 830
TQ 640

[Cast Iron Junkie]

JJ, could you please explain the difference between the SB2 and the SB2.2?

Thanks in advance.

[perfconn]

I'm not JJ but the early development of the SB2's saw a lot of junk on the market.Stay away from them at any price.They aren't as good as a middle of the road 18*.You can't find rockers and stuff for them either.
As far as which is best,18* or SB2.2,they both have good points.some engine builders won't even build SB2.2 because of their lack of bottom end.In that case they use the GB2000 or Dart 13* heads for big(4 inch stroke) motors and Dart 16* or 18* for smaller motors.
One thing you need to keep in mind is that any given stroke has an rpm limit.If you exceed that limit you will start jerking wristpins out of pistons.In the case of a 3.75 stroke the upper limit is 8200rpm.If you build a 400ci SB2.2 and have to turn it 8500 to get it off the corners than you will have trouble.Thats not saying it won't run just that it won't run long.

[Jimmy Judd]

Agree with Terry,


Though RPM #'s I gave were dyno sheet spects. I chip mine at 8-8200. To be honest, I see no reason to turn it over 8. The down side is you can't get it slowed up going with yet an even taller gear.

I have no problems, or the lack of bottom end TQ with mine. If any thing, its too much.

[perfconn]

JJ,thats the results of using a competent engine builder.Having the right size cam,intake,rockers and intake runner volume is critical in any engine.Size everything too big for an engine and it will look great on the dyno but will be a dog on the track.

[billetbirdcage]

Dam JJ .75 to 1.0 less gear!!! (also keep im mind JJ's engine and the other he was compairing to may have totally diference wieght components -- JJ's likely lighter then the others and may be comtributing to the gear difference and the decelleration forces JJ descibed.)

We generally are .1 lower with an SB2 verses a longer stroke18*.

I would agree with everything that JJ said. Hard to beat a good quaility SB2 in my opinion. Similar torque curves (maybe 100 to 200 rpm higher as JJ said) but carry the torque on out and produce around 50 more hp on the top end.

Only one complaint, and maybe jusr our combo: At extremely low RPM like a start it doesn't take off as good as the larger stroke 18* engines, but after that it will usually eat them up. Like JJ said it never quits pulling.

I have worked with some guys that have the GB2000 style heads they seem compairable the the SB2 from my limilted experience and little knowledge of their combos. They are usually larger in cubes then the SB2 but are pretty compairable power wise.

[perfconn]

Billet,most of the combinations using the GB2000,BD2000,SB2.2 topend are bigger engines because of the bigger port volumes.They may run on littler engines but you have to wring their necks to get off the corners.

[billetbirdcage]

What I meant was the limited exposure I have to the 2000 series heads is they seem to have use larger stroke then alot of the SB2's.

Just what I noticed, right or wrong?

[perfconn]

Pretty much the same size engines,388 or bigger.You see some guys try to build 358's with them but usually end up not happy.For the little motors the 18* is still the topend of choice by most engine builders but not many are built anymore.For a 4 inch stroke SB Chevy I think the BD2000 is the best head out there with the SB2.2 next.

[Jimmy Judd]

Billet,

Belleville NCRA - we ran the tallest gear I had, It was a 515 and still bumped the chip on the dog leg. I could see Boen, just couldn't catch him. When I say (see), You realize I mean a few hundred yards!

NRP, was a 535
Mayetta, was a 541
Corning, had in the 520
Lake side, 535 -chipped hard- ended up with the 520's for the heat's and feature.

Hell the deepest gear I own is a 568! I save this set for the 1/4 milers:D

8-82 chip

JJ

[billetbirdcage]

Belleville 5.28 or maybe 5.35ish if tracks real slow

You seem about .2 or so off in general, that's much better then .75 to 1.0

The smaller the track is the more you seem to be off. Good thing or bad thing? just going off what most are running on those tracks.

[Jimmy Judd]

Yeah, Most, if not all of my comparisons are from Anderson's 410's. Corse, I don't buzz mine 9000 either. Its the small motors up tp the 380's where I see the biggest jump