AS Engines - claimed vs actual output

[454]

Spotted this thread on the SXOC :

www.sxoc.com/vbb/showthread.php?t=101334

Half way down there's a post from someone who's mate apparantly has an Ultima :

QUOTE"Someone get a look under the hood, if it ways "American Speed" anywhere under the engine cowl, can someone point/laugh for me as it will be lucky to be producing over 400bhp
Ask what the cam duration is if its an American speed engine as there "custom ground cams" do not exist, and the compression ratio wont be anywhere near high enough.
If its not an AS engine,then respect
If its a supercharge American Speed engine then it only produces 460 bhp as seen in C&CC
If its not an American Speed engine then be affraid"QUOTE"

Now don't get me wrong, this guy probably has no clue what he is on about and I am planning on using AS to build my engine. I am interested, however, in other peoples experiences with AS engines though as there must be lots of you on this board.
I read the article on CJ's car and understand the dyno wasn't exactly up to the job and speculation was used to deduce a figure.
I know AS provide a dyno sheet with each engine but has anyone actually dynoed there AS engine themselves to verify / check for accuracy ?
It would be very interesting to put together a list of As engine users with AS's quoted output vs actual output on our UK fuel, this way we could calculate the accuracy of the average engine ?

[454]

cont ....

I know that dyno's also vary from one to another but this should only be a slight variance on engine dynos.

I've seen pages and pages of arguements about power figures at the wheels vs fly and conversion factors / transmission losses etc on different dynos so this could also be confusing the quoted figures somewhat.

All points for and against AS would be received with interest as we all spend a good chunk of our budget on the engine

Jez

[egomeister]

Another thing to consider would be whether the quoted outputs are in american HP or Uk HP - 1 US Horsepower is less than 1 UK Horsepower.

[ultimasimon]

..and also the adjustment factor for the altitude difference

[davefiddes]

egomeister said:

Another thing to consider would be whether the quoted outputs are in american HP or Uk HP - 1 US Horsepower is less than 1 UK Horsepower.

This is a red herring I'm afraid. 1 US horsepower = 0.99999983 UK horsepower.

I had my AS engined car on a chassis dyno a few months ago. The results were interesting. I showed up 400 bhp estimated crank hp v's the 456 on my AS dyno sheet. This is quite a difference however there are a number of issues I have found subsequently that contribute to this:

- I wasn't running full throttle due to a badly adjusted throttle linkage (only a problem on the dyno or occasionally on the racetrack)

- There was an issue with my clutch dragging (bent clutch master cylinder rod/inadequate pedal travel) that upset the transmission loss calculation a little.

- The rev limiter on my car is set to a conservative 6000 and starts to soft limit at pretty much exactly peak power. Some day I'll get the correct plug for my MSD 6AL.

- The Ultima std exhaust system is a lot more restrictive than an optimal header/open exhaust configuration on a dyno. When I had a loose exhaust clamp I found it was blowing quite a bit which indicated quite a significant amount of back pressure.

I figure that all of these things could easily contribute to the 56 bhp difference. The session I was at was with a bunch of Scottish PHers and the dyno itself seemed to be very well setup and reading pretty much on the button with what people were expecting (some thought it was high, others low - I figure it was in the middle).

On a more general note there is nothing I have seen in the build up of my engine that is anything less than best practice for race prep'd Chevy engines and American Speed are a great company to deal with in my experience. The only slight irritation is the total race focus of the engine...great on track but street drivability and gas mileage are poor (I have a solution for this...).

If you were concerned then I guess you could get your engine dynoed when it hits the UK.

[YIIHAA]

davefiddes said:

- The rev limiter on my car is set to a conservative 6000 and starts to soft limit at pretty much exactly peak power. Some day I'll get the correct plug for my MSD 6AL.

Which do you want? My engine came with a set of even plugs, and I bought a set of odds. Tell me which you are after and I might have one spare that I can send you.

[egomeister]

davefiddes said:

This is a red herring I'm afraid. 1 US horsepower = 0.99999983 UK horsepower.

Ah, so not much in it then! I knew there was a difference but not the size of it!

[tuxman]

the only way to be sure of power output is to build your own engine,remember torque and driveability are more important for road use

[andycanam]

After stipping my AS engine it actualy had slightly higher CR than quoted..... I also had it confirmed by Comp Cams that the cam in my engine was a custom grind by them for AS.

and yes I got it independantly dyno'd over here and it produced within 3% BHP of what I paid for......

So I am sorry to say your mate is wrong.

[PiB]

YIIHAA said:

davefiddes said: - The rev limiter on my car is set to a conservative 6000 and starts to soft limit at pretty much exactly peak power. Some day I'll get the correct plug for my MSD 6AL. Which do you want? My engine came with a set of even plugs, and I bought a set of odds. Tell me which you are after and I might have one spare that I can send you.

As an enthusiest of these cars I was just wondering about this. Even and odd plugs? You can't mean spark plugs can you? The msd kit amplifies the spark and repeats it really fast to improve combustion. Even and odd plugs what is that? Is it a fuse or something?

[BobM]

PiB said:

Even and odd plugs? You can't mean spark plugs can you? The msd kit amplifies the spark and repeats it really fast to improve combustion. Even and odd plugs what is that? Is it a fuse or something?

The MSD unit has a socket on the bottom which accepts a small 2 pinned plug to set the rev limit. These come in 500 rpm intervals, e.g. 5500, 6000, 6500, 7000 etc. which is the odd/even Dave was referring to. They're very similar to the crystals used in remote control radio sets to set transmission frequency. Dave has the 6000 in his and probably wants the 6500.

[andycanam]

BobM said:

The MSD unit has a socket on the bottom which accepts a small 2 pinned plug to set the rev limit. These come in 500 rpm intervals, e.g. 5500, 6000, 6500, 7000 etc. which is the odd/even Dave was referring to. They're very similar to the crystals used in remote control radio sets to set transmission frequency. Dave has the 6000 in his and probably wants the 6500.

I also have loads of these.... I'll have to have a look as to which ones though as I gave quite a few to the new owner.

[G Man]

Andy

Do you have a 8000 rpm one ?

G Man

[454]

Thanks for the comments so far

To clarify, the original quote I posted is just something I came across on another forum, the views it contains are not mine and the guy who wrote them is not an associate of mine in any way.

Just don't want anyone to think I have anything against AS in any way, I'm just trying to make that difficult engine decision that we all have to make at some point during the build

Jez

[Stig]

Just to confirm, the 460bhp in C&CC wasn't even reflective of the results we got on Dave's rolling road!

He had to calculate the power as his equipment couldn't handle the power - it was over 500bhp so why he shaved 40 brake off is anyone's guess?

This was without changing anything on a car that was tight, hot and with a poor carb mixture.

I'm still trying to find a suitable 'specialist' in the UK that can set up the carb properly on a road that can take the power.

Then again, this seems to be another example of someone who's 'mate' (of a mate, of a mate) is talking a load of cack.

PS. Se above comment regarding US vs. UK power differences hp is not the same as bhp.

[Stig]

LOL!

Just seen who the post is from - that plonker Vez (who pops in here every now and then to wind everyone up).

I believe he's a mate of adequatefast's (or shithotfast - can't remember) and is constantly knocking Ultima's.

Ignore him and hopefully he'll slide back into the hole that he comes from

[YIIHAA]

G Man said:

Andy Do you have a 8000 rpm one ? G Man

I do, and you're welcome to it, and I only live 20 mins from you.

As to evens / odds, you buy the crystals in sets from MSD, and I bought the odd set from them for the 6000-7000 rpm range, so have 6100, 6300, 6500, 6700 and 6900. I also have knocking around a 3000 (valet parking?), 7000, and 8000

[YIIHAA]

Stig said:

I'm still trying to find a suitable 'specialist' in the UK that can set up the carb properly on a road that can take the power.

In one of the issues of Ultimatum (before your time sonny ) one of the owners took his car to a rolling road in Woking. (no not McLaren)

Just looked it up and it is
GRL Motors

He recomended them and said they did a good job.

<disclaimer> not affiliated with them in any way </disclaimer>

[Boosted Ls1]

A bench dyno is accurate but a rolling road isn't so good. Thing is, you can easily lose 50-60hp through the transmission so if they say 460 odd at AS and you get 400 on the rollers it's not so far out.

[andycanam]

G-man
Yes I do have an 8000rpm one.... think I have every 100rpm from 7000-8000 if that interest you.

Also sorry if I sounded a bit touchy.... as CJ says this guy has spouted this before about AS.
Fact is I paid 600quid on the dyno to find out the truth and I think 3% aint bad especially across the pond.
Incidentally I did use the entire day and we did try to improve on the AS combination and everything we tried lost power even the mixture etc was spot on (I also dyno'd with and without the Ultima headers on).

My experience with AS was very good.... the engine arrived on time, was very reliable and in truth produced a real BHP closer to what I paid for than I expected.
I also stripped the engine down to inspect and dyno'd it (prior to the 0-100-0 race) and found it 100%.

saying that I still think an official 0-100 in 7.4s with proof that it could have gone another 0.4's faster (by not changing at 98mph!) speaks volumes for the engines performance anyhow.

Andy