Dyno numbers! Options

[bruecksteve]

I just got two books:
How to Rebuild Small-Block Chevy Lt-1/Lt-4 Engines: Step-By-Step Rebuild to Factory Specifications
and
John Lingenfelter on Modifying Small-Block Chevy Engines: High Performance Engine Building and Tuning for Street and Racing

Really good books on the small block engines and lots of insight and experience from Lingenfelter himself.

[trax]

Aah yes, the Mustang Dyno. I figured your numbers were from a DynoJet. I would say that your motor is in fact a pretty strong runner. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/smile.gif)

[Pilot]

That makes me feel better. If you want numbers to compare to everybody else, go to a Dynojet. They're the same every time--that wheel's mass doesn't change. With a Mustang dyno, god knows how the guy running the thing ran the thing so your results depend upon what he was doing.

AFAIK, not all Dynojets have the same drum mass. Some jets have 1 drum, some have 2... it all depends on what model it is.

[Jon A]

Correct, there are some models with different drums.

[redbird1]

Concidering all the experience that you all have I feel better after hearing that you guys feel better. The car does run very well. A little rough when cold but otherwise fine. The cam may be costing me some top end HP but the throttle response is incredable and the low end torque is one thing I was looking for.
As far as the flat torque curve. The early runs weren't so flat. The begining of the curve did not look anywere near this good, It arched in from the bottom of the graph. He then did some things with the Lower RPM air/fuel and it brought it to life.

Steve

[fa63]

As others have said, you might want to look into another cam. You would be surprised how tame even a big cam like GM 847 (234/242 112 LSA 0.575"/0.595" w/1.6 rockers, if I remember correctly) behaves with a 6-speed car in a 383ci engine (when it is tuned right). Good luck.

Tony

[Jon A]

Correct, there are some models with different drums.

For those interested, I looked it up. All the various model 248's (by far the most common) have two 48" rollers. Only the much smaller 224's have two 24" rollers. And of course the very few model 424's you hear about for those rally cars. They have four 24" rollers.

Man, I am so quick. I only stared at those specs for quite some time before it dawned on me what the model numbers stand for. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/blink.gif)

Now you'll all know, just by the model number. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/beerchug.gif)

[redbird1]

http://www.airflowresearch.com/

I just looked at AFR's web-site and noticed there recommendation on valve springs. Click on the LT1/LT4 link to the left, then click on the 195's. These are 195 heads and mine are a discontinued 190 model but I'm sure the theory still apply's. They mention upgrading springs when running hydraulic roller. I am going to have to get this done.

[redbird1]

I emailed the head manufacture AFR yesterday. I described my basic setup to him and asked what springs he would recommend. This is his response. Anyone have any experience with the hydra-rev kit?

Hi Steve

Rather than do a spring change you would be better off using our Hydra Rev kit, it will allow you to go up to 7000 rpm before you start getting into
vavle float. AFR is no longer doing updates to competition porting, but the 190cc heads you currently have on your 383 are capable of up to 500hp
if you stay out of vavle float. You still have plenty of cylinder head with out any additional porting for your application.

Scott Sperling
AFR Sales/Tech(
818) 890-0616 X102


Any thoughts?

Steve

[Formula WS6]

at this point i see the hydrarev kit as a bandaid instead of a solution. id change the springs out first then if your really gonna beat on it up to max rpms id look into the rev kit. those are my thoughts and how id do it personally.

[redbird1]

at this point i see the hydrarev kit as a bandaid instead of a solution. id change the springs out first then if your really gonna beat on it up to max rpms id look into the rev kit. those are my thoughts and how id do it personally.

I Agree. All I see myself doing right now is changing the springs.

[Jon A]

Screw AFR. A rev kit certainly isn't a bad idea, but you need to get those springs off the car!

[94bird]

Steve, guess I missed this thread until now. If you remember, I also ran the 224/230/112 XE cam last year in my 350. I was using 1.65 rockers however. I got 340 RWHP at about 5800 rpm on a Mustang dyno here in town. At the time I was using the 612 springs from Combination Motorsports. They were surprisingly cheap with retainers and locks and worked great.

If you plan on upping the cam later I'd go with better springs, but for the XE 224/230 the 612 springs are well within their range.