455 Dyno Results
 

Well I finally got my 455 on the dyno. I will list its' components and tell me what you guys think. 455-40 over, unmolested 1970RAIV 614 heads, Crower 60245, Dougs headers 9.5 compression ,original 1970RAIV intake , engine builders 950 Holley ( I know it is too big but the Quadzilla would not even allow the cam to be broken in ) . Could not get readings below 4000rpm because of dyno restrictions but here goes Max HP-436.2@5,500 and 520.7 lb/ft. torque @4000 I assume torque was greater at lower rpm but I have no way of knowing. Do you all think this is what is expected with this combo?

Nice job! Very cool build.

My first 455 using my SR 614 RAIV heads flat valves cleaned up a little in the pocket(all the rules allowed that year in NMCA), 72 SR-HO intake, SR 73 SD Q jet ,Ultradyne HFT 288/296 on a 108 LS through Hookers into mufflers on the dyno was about the same HP rpmed a little higher for peak. Ran 117mph in a 3950 lb TA with stiff road race suspension and 3.42s. Great street, autocross and drag combo. Even ran A/C!

I think those are "real" numbers that will hold up using wt/mph calculations. Higher dyno numbers will not match track numbers. Some dynos are "generous" and won't run the numbers.

Can you post the dyno sheet ?

Yes,
At 4000 rpm that combo was starting to get on the down hill side of peak torque numbers, but still holding on to 520 ft lbs at 5500 is doing good.

I would have expected a bit more HP though out of that Cam!
I would have expected closer to 450.

Was it installed advanced and do you know what the cranking compression is?

Actually for future reference you should take the time to find this out while the motor is fresh,

The cam was advanced 4 degrees. It held on to the 520 at 4000 rpm's. That was the first reading we could get-something about water grabbing the dyno-I really did not grasp that notion but I am certainly no authority. I will tell you the dyno numbers pulls I do not know how to post them and yes I agree-I also thought 450 . 4000-396.5hp,520.7 tq / 4100-398.5 & 510.5 / 4200 403.8 & 504.9 /4300 405.7 & 495.5 / 4400 408.5 & 487.6 / 4500 409.2 & 477.6 / 4600 408.5 & 466.4 / 4700 / 410.4 & 458.6 / 4800 / 412.7 & 451.6 / 4900 415.6 & 445.4 / 5000 418.5 & 439.6 / 5100 422.6 & 435.2 / 5200 / 427.6 & 431.8 / 5300 432.0 & 426.1 / 5400 435.1 & 423.1 / 5500 436.2 & 416.6 I wonder if the carb adapter used to mount the square bore Holley hindered performance and I do think the carb was too big-950cfm. The problem I have is that my car is tying up a lift in a garage and I just cannot extend my welcome any longer awaiting a different carb. This carb the builder had on hand. Thanks all for the comments.

Curious, but how much power did you expect it to make? For all intensive purposes, it's a stock type 9.5 to 1 455 with headers, and for that reason, I personally feel like that is the wrong choice in cam timing..

Interesting build ….how much dish on the pistons to arrive at 9.5 to one with those heads? Would have probably helped the cam some to get the compression at 10 to one or higher.

Are you running one of those squeeze down the primary's carb adapters for the 950 Holley on the RAIV intake ?

Interesting. At 4000 RPM the torque is really falling and 5500 RPM HP has not yet peaked.

Stan

taktikian
Were any dyno pulls made past 5500 rpm ?


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Very cool build! The numbers look very nice go me. I like the way they are spread out with the peak power up at 5500. Possibly spread out even more than the dyno pulls recorded looking at Stan’s graph. Should be the makings of a very fun pump gas friendly street engine.

Out of curiosity what fuel was it dynoed with? I do recall Scott70 on this forum did the holley and qjet swap on the dyno and his stock intake and picked up 8 hp with the qjet. A little more dyno time I bet 450 would be pretty close.

I used Ross pistons from Butler with 27.3 dish and Cometic .040 crush head gasket

Really do not know what adapter was used. Was really a body blow when the SMI would not run. Screwed up everything.

No. Was looking for 450 hp and figured I was close enough. Did not really want to risk it. This build was going on forever and I needed to get it done.

I would love to use the Q-jet but it has to run run properly. Do not like to have to change fuel lines and enter more variables into equation. If a Q-jet guy was readily available I would do it in a heartbeat. Not even absolutely sure what Holley this is. I am not stupid but I am time constrained .

I also thought the torque fell unexpectedly quickly. Do you have any ideas?

I think I know what you are going to say but what HFT cam do you think would have been preferable?

For all those that think 4 hole adapters to Q jet intakes "kill flow" personal at track experience. San Antonio track my 455 with E heads small roller had a 72 HO intake and a Brad Urban 73 SR SD Q jet 800cfm that ran good to keep the Shaker until I modified an extra base to clear the Holley/Demon bowls(front a BFH rear esp Holley I grafted a piece off a cheap drop base air cleaner). So at the track swapped an adapter and an 850 DP Demon out of the box the idle was right on and it picked up 0.2 seconds an 3 mph. So I guess it did not hurt flow that much. Eventually swapped on a Torker II that picked it up a bunch.

How tall is the adapter Skip?