Crate engine HP ratings
Thread Starter
Instructor
Joined: Jun 2008
Posts: 100
Likes: 1
Crate engine HP ratings
Getting ready for a new, more powerful motor and was considering the Year One 400hp motor. At a local car show, a guy mentioned he did a swap for a 400 hp motor and was really disapointed with the results.I know builders throw out big numbers, but not to include the belts, a/c etc. I am not building a race car but do not want this problem. I see the zz4 motor, but it is rated lower. What is the HP number I need to start with. Any can't miss engine swaps that has worked in the C-3?
Racer
Joined: Mar 2008
Posts: 315
Likes: 0
From: KY
The more displacement you can get the happier you are going to be.
Just dont look at advortised hp numbers look and see where the power comes in a larger displacement engine with the power coming in low in the rpm range will be fun on the street.
Lots of torque to squish you into the seat and smoke the tires.
Just dont look at advortised hp numbers look and see where the power comes in a larger displacement engine with the power coming in low in the rpm range will be fun on the street.
Lots of torque to squish you into the seat and smoke the tires.
Racer
Joined: Aug 2007
Posts: 267
Likes: 0
From: Springdale Arkansas
http://www.tonybarkerracingengines.c...NGINETEST.html
If I had to buy a crate engine it would be this one, I've bought parts from Tony and he did the machine work on my last block. He has a spotless reputation amongst the racing community where I'm from. Nice guy who knows his stuff and knows how to make power. For those of yuo who have never driven or have never taken a ride in anything with this much power this engine would be a freak on the street
FWIW, Jimbo
If I had to buy a crate engine it would be this one, I've bought parts from Tony and he did the machine work on my last block. He has a spotless reputation amongst the racing community where I'm from. Nice guy who knows his stuff and knows how to make power. For those of yuo who have never driven or have never taken a ride in anything with this much power this engine would be a freak on the street
FWIW, Jimbo
Last edited by jimboscarbs; Feb 6, 2011 at 11:28 AM.
Melting Slicks
Joined: Mar 2007
Posts: 2,100
Likes: 12
From: Frederick Maryland
Crate engines are rated in gross horsepower, not net horsepower. The manufacturer doesn't know what kind of car it will be installed in or what equipment will be attached, so gross hp is about the only honest way they can advertise it. You have to figure in at least a 15% parasitic loss from advertised gross hp once the engine is installed.
As much depends at what rpm the hp makes its peak...is that peak where you want it for your needs?
We talk horsepower but we drive torque.
As much depends at what rpm the hp makes its peak...is that peak where you want it for your needs?
We talk horsepower but we drive torque.
Le Mans Master
Joined: Oct 2010
Posts: 6,936
Likes: 848
From: melbourne florida
2023 C3 of the Year Finalist - Modified
people think an engine solves everything,but gears and converter flash speed are a big contribution. the Guy with the 400 h.p. motor has the wrong setup
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Race Director
Joined: Apr 2007
Posts: 14,062
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From: Henderson Nv-Rohnert Park/Sonoma C o. ca/born in NY Rockaway Beach.
Just for an example.. My zz4 with shorties 2.5 all the way back curved dist and tuned carb by henry,and everything the same and it dyno'ed to the wheels at 260 dont know tq right now have to find it.. and my motor was rated at 355hp... And that is a big jump from my dyno'ed stock l48 at 169hp.. And I still want more now.. I want the Hot cam... and then im good...LOL right..
Racer
Joined: Aug 2007
Posts: 267
Likes: 0
From: Springdale Arkansas
Don't kill the messenger
Just for an example.. My zz4 with shorties 2.5 all the way back curved dist and tuned carb by henry,and everything the same and it dyno'ed to the wheels at 260 dont know tq right now have to find it.. and my motor was rated at 355hp... And that is a big jump from my dyno'ed stock l48 at 169hp.. And I still want more now.. I want the Hot cam... and then im good...LOL right..
12480002 350 Hot Cam Kit
This off-highway camshaft kit has the major valve train component to convert production LT1 engine for showroom stock racing, or hop up your small block Chevrolet V8 that was originally equipped with a roller tappet camshaft. The 1.6 roller rockers, light weight valve spring caps, special designed valve springs and hot camshaft offers a significant gain in horsepower at a reasonable price. This kit includes the following items: one camshaft P/N 24502586, 16 roller rocker arms kit P/N 12370839, 16 valve springs P/N 12551483, 16 valve caps P/N 10212808, 16 valve keys P/N 24503856, 16 valve spring shims P/N 10212809.
Technical Notes: This kit does not include roller tappets. See valve lifter section 0.459 for the lifter kit.
Last edited by jimboscarbs; Feb 6, 2011 at 02:37 PM.
Race Director
Joined: Jan 2000
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From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
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2017 C2 of Year Finalist
We just did a Dart SHP 400" motor and we had to strangle it with a 283/270 HP intake and 2 WCFB's to get it to *only* make 500HP on the dyno. With a dart dual plane and a 750 Holley it made 540 Hp and with a Weiand single plane it made 555 HP. All on pump gas and it's driving around just fine in a '61 Vette with a TKO trans and 3.36 gears and hubcaps!
We used a solid roller because the owner wanted it, but the same power could be made with a similar Hyd roller since it peaked HP in the 6000-6300 RPM range depending on intakes. It *only* made 520 lb ft of Tq!!
The Dart package is a neat deal. Instead of getting what the crate guys give you, which is often just stock stuff with a cam and maybe a little better heads...you can pick how strong you want it and go from there with options.
JIM
We used a solid roller because the owner wanted it, but the same power could be made with a similar Hyd roller since it peaked HP in the 6000-6300 RPM range depending on intakes. It *only* made 520 lb ft of Tq!!
The Dart package is a neat deal. Instead of getting what the crate guys give you, which is often just stock stuff with a cam and maybe a little better heads...you can pick how strong you want it and go from there with options.
JIM
Race Director
Joined: Jan 2000
Posts: 13,017
Likes: 2,261
From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
C2 of Year Winner (performance mods) 2019
2017 C2 of Year Finalist
It was a custom Comp 248/248 on a 109 LSA. It's being covered in Auto Enthusiast Magazine. Here's part 1. Part II coming soon..just proofed it all last week.
Starts on page 76.
http://editions.amospublishing.com/K...01&pagenum=&f=
Didn't try any larger carbs. The intent was to show what we could literally spec out, take out of the boxes, bolt together and stick it on the dyno. If I had spent the time to do my *normal* tricks we'd be looking at a lot closer to 600HP for sure. There was no port work at all on the as cast heads, intakes etc. We played with jetting a little but it was pretty close out of the box.
Really pretty impressive for what it is though. Dart has a good program going with those as compared to normal *crate* motors for sure.
JIM
Starts on page 76.
http://editions.amospublishing.com/K...01&pagenum=&f=
Didn't try any larger carbs. The intent was to show what we could literally spec out, take out of the boxes, bolt together and stick it on the dyno. If I had spent the time to do my *normal* tricks we'd be looking at a lot closer to 600HP for sure. There was no port work at all on the as cast heads, intakes etc. We played with jetting a little but it was pretty close out of the box.
Really pretty impressive for what it is though. Dart has a good program going with those as compared to normal *crate* motors for sure.
JIM
Le Mans Master
Joined: Sep 2004
Posts: 5,116
Likes: 5
From: Livonia MI
Don't think it's fair to call crate motor's gross hp like what went on in the 60's, as most are engine stand dyno pull's with full cooling system, alternator, but minimal exhuast through long tube header's. Real world hp will surely drop a bit through full exhuast, but even sae number's are at the crank, not rwhp. I agree that high hp rating's from small cu. in. really isn't the best choice for street use. Keep an eye out for good hp/torque number's at lower rpm's, and more cu. in. certainly wont hurt.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Your problem may be that the new "crate" engine is just not tuned properly. What have you done in the way of timing optimization? Are you getting full opening of the carb secondaries when the accelerator pedal is depressed to the floor? Did you tune the carb at all, or just bolt it down and go for a run?
There is usually a lot of HP/torque left on the table after a crate is first installed in the car.
There is usually a lot of HP/torque left on the table after a crate is first installed in the car.
Safety Car
Joined: May 2003
Posts: 3,814
Likes: 105
From: Dearborn Heights Michigan
Seem to remember that Year One motors come with a dyno sheet.
A year or so ago "Hot Rod" engine dyno tested a GM ZZ4 rated at 355 HP that came in at 314.
My ZZ4 with 3:73 gears screams!
A year or so ago "Hot Rod" engine dyno tested a GM ZZ4 rated at 355 HP that came in at 314.
My ZZ4 with 3:73 gears screams!
