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hyd roller cam 496 dyno session

18K views 67 replies 24 participants last post by  Harris Roc Malouda 
#1 ·
On Monday 2/3/2020 i will have an opportunity to dyno my 496 with the Straub cam and AFR315. The shop doing the dyno session is graciously providing me a chance to figure out what parts I have make the most power.
current: 4.31 bore Gen V gm block, 10.3:1, autotec 21.2 cc domed pistons, Molnar tech rods and crank, vic jr intake, 1050 4150 cfm carb,msd distributor, 2 1/8" primary tube hooker headers, Morel lifters, and Straub Hyd roller cam. The will be a belt initially to only run the water pump.

We are going to run it with the mid pipes like I do at the track when I run open. With the Fitech i need at least a collector extension to accommodate the o2 sensor. Get it dialed in and average 2 pulls. After that we intend to test the following.

Set 2. Add flow master mufflers (my drive around mufflers) NOTE: I have seen my ET improve by as much as .37 seconds by going open header.

Set 3. swap to Dynomax race masters with similar length pipe. never been on the car but are certainly a candidate pending the results

Set 4. Alternator tests. I feel like mu high amp Powermaster cost me some power based on ET last fall.

Set 5. Lower amp duralast that I ran up until the powermaster was installed in August 2019

Set 6. 10.3 compression, 496, afr315 heads, Sniper jr, 2 1/8 headers, mid pipes, 4500 dominator

Set 7. 11:1 compression 496, ported afr265 heads, team g, 2 1/8 headers, mid pipes, 4150 1050 cfm QB main body carb

All testing with the Straub hyd roller. I'd like to start 2020 with a 700 HP NA deal and spray when needed.

Here is a link to my AFR315 thread.
https://www.chevelles.com/forums/13-performance/1043025-2018-496-phase-3-plan-afr315-heads.html

Link to a recent youtube video
https://youtu.be/fp8hLZGN-hU

Some different guys with small businesses helped me so I'd like to figure out a HP/TQ type contest to give away some of their t-shirts. TBD
 
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#11 ·
I do not know anyone with 2" primaries nor have I come across any at a price point that would allow me to acquire them. The one time I flirted with the idea of Doug's or some header like that they were always back ordered. I'd love to have tried some.
I got a good deal on the hookers so I can't complain. I have thought about doing a 500+ incher with the Molnar parts. I just haven't found a deal on a block yet.
 
#6 ·
I could be wrong ? I thought this member did a 2inch to 21/8 test and it picked up like 20hp+? with the 2/18

I know my 2inch blocked the exhaust ports a good bit with my AFRs
 
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#10 ·
I saw 20+ hp gains in an important RPM range going from 1 7/8 to 2 1/8.
 
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#7 ·
The alternator shouldn't impact anything. If the battery is charged the alternator is only going to charge based on system draw. Doesn't matter what the output of the alternator is unless you max out the low output alternator.
 
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#9 ·
we did a lot but have 1 combo left with 2 scenarios. That Sniper Jr fought us on fitment with the AFR intake gasket. we had to swap out to a FelPro 1275 s-3. It was hard to find but Creason Racing engines down the road a bit had one. we just wasted too much time trying to make the AFR gasket work. not it's supposed to be under 50* for the next 2 weeks. Not sure what will happen. he has other customers that he needs to get on his dyno. Mine may come off so he can get the other engines out the door. I will post results over a couple week span so we can give away a few t-shirts for guesses. That still needs to be figured out.

The AFR265s and Team G are back on. We are going to run with the midpipes to get the AFRs in line then go open. we noticed an improvement when doing so with the Sniper Jr and Dominator.
 
#12 ·

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#14 ·
If you want to try for a t-shirt, answers are accepted on twitter. Hp and tq combined closest.
 
#16 ·
a long interesting day. not sure why i kept thinking the dynomax mufflers were called race masters. they are actually Ultra Flow.

this was 10 fast and interesting hours. I botched the order with one section.

https://youtu.be/o4K0LeQiFW0
 
#18 ·
Looks like you tested the Vic Jr. vs the Team G, what were your thoughts on the intake swap?
 
#19 ·
It ran the same more or less. The vic jr lined up better to the ports but the difference in ET was not noticeable.
I think early to mid next week the team G gets a few pulls with this Straub cam and the matching 265 heads.
 
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#20 ·
No Audio? BOOOOOOOOOOO! :D
I had to look at the breather and exhaust to see if they were in a pull.
Hopefully there's no houses in that area with the way the exhaust goes out the door. My engine dyno guy has his fuel cell/reg n pump in the room with him.
 
#21 ·
I have plenty of audio coming. We made a lot of 6800-7000 rpm pulls.
 
#24 ·
In this form
4.31 bore Gen V gm block, 10.3:1, autotec 21.2 cc domed pistons, Molnar tech rods and crank, vic jr intake, 1050 4150 cfm carb,msd distributor, 2 1/8" primary tube hooker headers, Morel lifters, Straub Hyd roller cam, and 3" OD mid pipes

The combined hp and tq was 1321.7

Details a little later
 
#31 ·
#32 ·
so it peaked at 6500? i was off by a 100 rpms ,sounded good .
a pan evac and you would crest 700hp ,more with a vac pump.
where do you have timing set?
 
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#36 ·
so its down 50hp from peak 6500 to 7000.

what rpm do you trap ? I see we both pick up 26mph in the back half

mine pulls like a beast to about 1100 feet then goes soft I trap 7000.

Have you adjusted preload on the dyno to see if its worth anything?
 
#38 ·
Thanks for sharing your information. I will have a similar build 505 on the dyno soon. Gives me something to compare to.
 
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#41 ·
Fresh hone and total seal rings coming.
 

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#45 ·
It's back together and hitting the dyno again in the next week.
 

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#48 ·
https://youtu.be/BaTf1VIEKww

The refreshed and slightly altered mill is ready. In 2018 I got a good deal on some afr315s and wondered if they would outperform my ported afr265s. I did a typical magazine test and used the same cam. The 315s were a bit lazier down low. I did some spring changes in the distributor to close that gap on the loss in 60'.
Right before drag week I installed a Chris Straub custom cam for my combo. Things didn't seem to pickup as much as I had hoped. I wanted a single digit 3600 lb NA street car and my times were not there. During drag week that year Chris held an event and we got to talk and see his place. It was a really cool event he put on. He mentioned the track elevation and possible DA. I made the decision to run open header at Bristol. That opened my eyes to how my car was being slowed down by my 3" exhaust. More than adequate for previous engines. After drag week on a cool autumn night I went 10.06 @ 133. So close to my goal.
This off season I talked to my local machinist about how I wanted to know what heads and intake and what cam presented the best possible chance to meet my goal. Shane Fessler was very interested to see this as well so we set out to test my options.
Option 1. 496 with custom CS cam and 315s. This made 692 hp with a mid pipe and probably 710 if we went open header but we didn't because we wanted it in race trim at the time.
Option 2. was using borrowed dominator and sniper jr, this made about the same power as with my vic jr and 4150 with mod pipes. We removed the mid pipes and bang 715 hp.
We did muffler testing as well and now I know what to run on the street.
Option 3. My Fessler ported afr265 heads with CS cam. This would bump the compression from 10.3 to 11:1. The dyno was acting up when it was time to test so we never had a solid answer. The numbers seemed inflated but better than anything to that point but we couldn't trust them.
We did the torque plate kiss of a hone and added some total seal rings. He had other customers to get through his shop and many get his dyno services. We assembled the engine last week then broke it in and pulled the handle on 4/26/20.
Option 3 now officially has numbers and it will be my race week and event mill until it gives up or I turn 50 (4 yrs). This has no choice but to get me single digits. We made 2 pulls and took the average of the data.
Hp 726 at 6200 rpm
Lb ft 665 at 5000 rpm
I will be spraying the car at some events but hope to do rocky mountain race week NA class again with my Fitech.
 
#53 ·
The power with the AFR265 just shows the bigger is better mentality is wrong! And yet many people still argue that the 265's are way too small for an engine unless you are making a street or tow vehicle.

And I still argue with guys that the Flowmasters are huge power losers!
 
#49 ·
Good job getting the blow by under control.

Why is so much fuel being drawn out of the accelerator pump discharge nozzles? Looks like a lot of fuel!
 
#50 ·
Even with that it was lean in the beginning and in the zone by the end. He wanted to mill the nozzles a little but I mostly run a Fitech so I didn't want to spend too much time on it. The carb is hardly used.
 
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