615 SR20 or 632 12 Degree

December 30, 2017, 10:51 AM

Will Harrison

quote:
Originally posted by TORQIN:
My 632 steel block with older big chief spreadports and nitrous kit & bottle weighed 2020lbs, my aluminum 598 SR20 weighs 1890 with nitrous kit & bottle both in the same car.

Both ran the same ET at the 1/8, my 598 now makes 70 more Hp...curious to see the improvement on the track...will see in about 5 weeks.

that sounds about right, an aluminum tall deck block is about 130 pounds lighter then a iron aftermarket block.... which is exactly what you gained

December 30, 2017, 10:57 AM

RPROGAS

Dollar for dollar, I would rather build a aluminum SR20 618, I believe it would be a more competitive combination. That weight difference (aluminum block over an iron block) verses the power increase of the 12 degree combination is the game changer for me.

Just my two cent opinion.

Bob

December 31, 2017, 08:17 PM

Will Harrison

So I weighed my 12 degree stuff since its apart right now.

Manifold is 19 pounds with carb studs
Heads are 38 pounds bare each
Valves are 4 pounds, all 16
Rocker stands are 10 pounds with all bolts and shims
Rockers are 5 pounds all 16
Pushrods are 3 pounds
Valve springs w/ retainers 4 pounds
Valve covers 4 pounds

For a grand total of 125 pounds...

I don't see a whole lot of room for taking a bunch of weight off the car there

December 31, 2017, 08:33 PM

racerdude2054

quote:
Originally posted by Will Harrison:
So I weighed my 12 degree stuff since its apart right now.

Manifold is 19 pounds with carb studs
Heads are 38 pounds bare each
Valves are 4 pounds, all 16
Rocker stands are 10 pounds with all bolts and shims
Rockers are 5 pounds all 16
Pushrods are 3 pounds
Valve springs w/ retainers 4 pounds
Valve covers 4 pounds

For a grand total of 125 pounds...

I don't see a whole lot of room for taking a bunch of weight off the car there

the weight is not saved from the heads themselves so much as much as it is from the configuration of the entire motor from 618 to 632

December 31, 2017, 08:34 PM

racerdude2054

a 598 SR 20 is also lighter than a 618 SR20 due to moving to a tall deck block on the 618 or 632

January 01, 2018, 06:34 AM

Spanky@Wilson Race Engines

I have built both. Your speadport stuff will always out mph the SR20 stuff. As far as reliability the SR20 stuff is pretty good.

January 01, 2018, 07:19 AM

1320racer

quote:
Originally posted by Spanky@Wilson Race Engines:
Your speadport stuff will always out mph the SR20 stuff.

As I stated in the first reply to this thread.

January 01, 2018, 12:09 PM

TOP38

quote:
Originally posted by Spanky@Wilson Race Engines:
I have built both. Your speadport stuff will always out mph the SR20 stuff. As far as reliability the SR20 stuff is pretty good.

spanky. Always is a dangerous word. And spread port is not specific enough also.

January 01, 2018, 05:19 PM

diceman1530

Why not a 632 SR20 ?
17 cubes at 2hp per cube,every little bit helps.

January 01, 2018, 06:09 PM

WHOMPWHOMP

Weight for one...

January 03, 2018, 05:54 AM

The Bozman

quote:
Originally posted by 1320racer:
The OP stated he wanted a “high mph SC combination” and I have yet to see with my own eyes an Sr20 headed 600+ bbc run as much mph as a spread portheaded 600+ bbc in similar weight dragsters competing in super comp here in division 1.

Further, as I stated in another thread, there are currently only 3 cars in the division that run better mph than my car in SC, two of them are sr20 engines and they run 1-1.5 mph faster and the other is a spread port engine that runs 2+mph faster.

Last, if I lived on Long Island, James Antoneli would be building my super comp engine.

Ed,
Our 615 SR20 motor ran 191 in SC trim at 1940lbs so it can be done, but that was with a cam that was almost 1" of lift and hard on valve train. If I wanted to go fast in SC I would do the 12 degree myself.

January 03, 2018, 06:08 AM

racerdude2054

I dont think anyone should disagree that the 12* is going to out mph the SR20 in an apples to apples situation

January 03, 2018, 06:38 AM

1320racer

that's what the OP asked.

That said, in my opinion the OP should be more concerned with his choice of engine builder for either of these costly and high HP engines. A Professional engine builder who has built hundreds of these engines, proven in the dyno room and more importantly on the track, will produce more reliable power and therefore highest MPH than the guy that does a few engines for friends. Further, I am not aware of one super comp racer, currently competing in NHRA Division 1 running either of these engines built by the OP's builder.

January 03, 2018, 08:26 AM

Tony Barrett

quote:
Originally posted by 1320racer:
that's what the OP asked.

That said, in my opinion the OP should be more concerned with his choice of engine builder for either of these costly and high HP engines. A Professional engine builder who has built hundreds of these engines, proven in the dyno room and more importantly on the track, will produce more reliable power and therefore highest MPH than the guy that does a few engines for friends. Further, I am not aware of one super comp racer, currently competing in NHRA Division 1 running either of these engines built by the OP's builder.

Thank you very much for all your input it has been very helpful. My engine builder works for a large well established race engine builder but builds my engines on the side. I totally agree with you that you need to have an established builder build one these.

January 03, 2018, 11:35 AM

"The Bender"

Build a mild conventional head 565, put a small blower on it, enjoy the low maintenance and run big mph.

My 2¢

272" Spitzer
540 Chevy
The Blower Shop XR1
FTI XPM Series Converter
FTI Level 6 Powerglide
3.69@199
.916 60'

2017 Bradenton Heads Up Madness
Open Outlaw Champ

2018 PDRA T/D #5
2019 PDRA T/D #2

2020 Retired From T/D Competition....

2020 Bradenton NMCA Hemi Shootout Winner

2021 getting back into bracket racing with a Gen3 Hemi powered 87 Cutlass.

January 03, 2018, 02:07 PM

MightyBirdF145

Hey Tony, good luck with the new combo.....whichever you choose.

FWIW, I love my SR20, but apples to apples you will get a little more speed out of the 9-12* stuff. The weight is something to consider too. I've been just shy of 185 @ 1950 #'s. Give me a shout if you have any questions.

Shawn

January 03, 2018, 07:17 PM

1320racer

No surprise, MightyBirdF145...KNOWS!

January 03, 2018, 09:12 PM

TOP38

quote:
Originally posted by MightyBirdF145:
Hey Tony, good luck with the new combo.....whichever you choose.

FWIW, I love my SR20, but apples to apples you will get a little more speed out of the 9-12* stuff. The weight is something to consider too. I've been just shy of 185 @ 1950 #'s. Give me a shout if you have any questions.

Shawn

Shawn and Ed

We all know stop MPH is as much about HP and the T Stop set up! Both contribute to finish line MPH.

What will high mph t stop setup loose vs all out, 2, 3 mph ???

My combo adjusted to Shawn's weight would MPH between 192.5 to 193.5 all out so I'd guess a high mph t stop setup would run 190 on my Pro 20 632 adjusted to Shawn's weight.

Also your typical 9 or newer 12 degree (older profiler's need some help) combo's should make more steam than the SR20/Pro20 combo's but the lose of 25 pounds does basically equal out on track performance or dam close. The older 18 degree stuff will be slower than the SR/PRO 20 combos also!

This is what I have seen with all the combo's as noted above that I know what's is in these types of engines which allows me to put them in and apples to apples comparison.

This message has been edited. Last edited by: TOP38,

January 04, 2018, 05:36 AM

Tony Barrett

quote:
Originally posted by MightyBirdF145:
Hey Tony, good luck with the new combo.....whichever you choose.

FWIW, I love my SR20, but apples to apples you will get a little more speed out of the 9-12* stuff. The weight is something to consider too. I've been just shy of 185 @ 1950 #'s. Give me a shout if you have any questions.

Thanks Shawn. I am just trying to get as much info as can right now.

Shawn