Dyno etiquette? - Page 2 - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #16 (permalink)  
Old 01-27-2011, 10:10 AM
v8hed's Avatar
AK427
 
Last photo:
Join Date: May 2008
Location: Northampton, UK
Age: 40
Posts: 794
Wiki Edits: 0

Thanks: 1
Thanked 3 Times in 3 Posts
Quote:
Originally Posted by ap72
If you're running the springs spec'd for that cam I wouldn't sweat running them with the inners for break in, assuming you have good oil and the engine was built well. You'll be wasting time removing them and reinstalling them, and it takes well over an hour, you can spend half the day just doing that.

Remove the valve covers, remove the rocker arms, remove the locks and retainers, replace the springs, reassemble. BTW, you need something to hold the valve stem in place when you change springs, if it slips down at all it makes installing the locks near impossible and placing all 16 retainers back on without bumping the valve and causing it to drop is not likely.

Also, I'd be sure to run your initial lash a hair on the tight side.

What intake manifolds will you be changing to/from? What carbs?

You're the first person I've seen say it's not necessary to remove the inner springs for cam break-in... these are Comp 987-16 with 120lbs seat and 320lbs open. I'll be making sure the valvetrain geometry is spot-on... correct pushrod length, correct lateral rocker tip alignment, correct installed height on every spring, plenty of coil bind clearance and retainer-to-seal clearance, etc, etc. Oil will be Joe Gibbs BR break-in oil AFAIK.

Curious, why do you recommend running the initial lash a hair on the tight side? Comp state .022" lash (hot), so I was planning to set the cold lash @ .017". Sound good?

Regarding intakes, I have a Victor Jr and an early Performer RPM (non Air Gap) that I want to compare... I may also cut a notch in the plenum divider in the Performer RPM intake before it goes on the dyno.

Carb is a brand new in the box stock Holley 750 DP (4150) and I also have a Quick Fuel Q-750 DP (similar to the Holley HP series I'm told) to try.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #17 (permalink)  
Old 01-27-2011, 10:30 AM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 60
Posts: 5,031
Wiki Edits: 1616

Thanks: 128
Thanked 598 Times in 547 Posts
I've gotten away w/breaking in a FT cam w/that much pressure on the seat. As long as you're not exceeding the open pressure spec's lift, you might get away w/it, too.
Reply With Quote Quick reply to this message
  #18 (permalink)  
Old 01-27-2011, 11:13 AM
Banned
 
Last photo:
Join Date: Jun 2005
Location: St. Louis, MO
Age: 29
Posts: 9,566
Wiki Edits: 0

Thanks: 20
Thanked 403 Times in 376 Posts
the Vic Jr and the RPM are 2 completely different intakes, you should know which one best suites your engine before you even bolted anything together, If its a street engine I wouldn't even waste your time with the Vic Jr. Comparing carbs could be a good idea, as they can have a significant impact, as would trying different carb spacers.

On the cam, as long as the lifter bores were checked and you use good quality lifters with face oiling i wouldn't sweat it. I also wouldn't run a solid flat tappet cam otherwise. I'd run .015" cold lash, your parts will wear slightly during break in which will add a slight amount more lash and running them tight will minimize bouncing. In all honesty the .002" lash probably won't make a difference but I always go a little on the tight side.
Reply With Quote Quick reply to this message
  #19 (permalink)  
Old 01-27-2011, 11:22 AM
v8hed's Avatar
AK427
 
Last photo:
Join Date: May 2008
Location: Northampton, UK
Age: 40
Posts: 794
Wiki Edits: 0

Thanks: 1
Thanked 3 Times in 3 Posts
Quote:
Originally Posted by ap72
the Vic Jr and the RPM are 2 completely different intakes, you should know which one best suites your engine before you even bolted anything together, If its a street engine I wouldn't even waste your time with the Vic Jr. Comparing carbs could be a good idea, as they can have a significant impact, as would trying different carb spacers.

On the cam, as long as the lifter bores were checked and you use good quality lifters with face oiling i wouldn't sweat it. I also wouldn't run a solid flat tappet cam otherwise. I'd run .015" cold lash, your parts will wear slightly during break in which will add a slight amount more lash and running them tight will minimize bouncing. In all honesty the .002" lash probably won't make a difference but I always go a little on the tight side.

There's quite a bit of testing that disagrees with you on the intake front and my combo has been tested elsewhere with both intakes and the Performer RPM with plenum divider notch v.nearly equalled the Victor Jr up top with some gains lower down. Likewise, there are plenty of people running Victor Jr intakes on street motors as they've found (on their combos) the Victor Jr still gives decent torque lower down. The only way to tell is to test on the dyno. And, FWIW, the guy who recommended this combo to me (the same guy that will be dynoing the engine and who has built hundreds of street and race motors) knows it's a 99% street-driven car and he specifically recommended the Victor Jr. intake as that's what he's seen make results with this combo on the dyno. I just want to try the Performer RPM as I've seen the dyno sheet from elsewhere that suggests it might be a touch better for me. We'll see.

The lifters are Comp Cams regular solid lifters... not the EDM model.
Reply With Quote Quick reply to this message
  #20 (permalink)  
Old 01-27-2011, 12:21 PM
Banned
 
Last photo:
Join Date: Jun 2005
Location: St. Louis, MO
Age: 29
Posts: 9,566
Wiki Edits: 0

Thanks: 20
Thanked 403 Times in 376 Posts
Quote:
Originally Posted by v8hed
There's quite a bit of testing that disagrees with you on the intake front and my combo has been tested elsewhere with both intakes and the Performer RPM with plenum divider notch v.nearly equalled the Victor Jr up top with some gains lower down. Likewise, there are plenty of people running Victor Jr intakes on street motors as they've found (on their combos) the Victor Jr still gives decent torque lower down. The only way to tell is to test on the dyno. And, FWIW, the guy who recommended this combo to me (the same guy that will be dynoing the engine and who has built hundreds of street and race motors) knows it's a 99% street-driven car and he specifically recommended the Victor Jr. intake as that's what he's seen make results with this combo on the dyno. I just want to try the Performer RPM as I've seen the dyno sheet from elsewhere that suggests it might be a touch better for me. We'll see.

The lifters are Comp Cams regular solid lifters... not the EDM model.
So you've seen the RPM perform better on countless tests and you still want to test something else? Just look at the runner CSA, flow, and length, RPM has street written all over it, the Vic Jr is better suited to small ci circle track engines.

I'd run the RPM and forget about it, spend you time tweaking that combo with carb tuning, ignition tuning, and spacers. JMO though and its probably not worth $0.02.
Reply With Quote Quick reply to this message
  #21 (permalink)  
Old 01-27-2011, 12:58 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 60
Posts: 5,031
Wiki Edits: 1616

Thanks: 128
Thanked 598 Times in 547 Posts
Quote:
Originally Posted by v8hed
There's quite a bit of testing that disagrees with you on the intake front and my combo has been tested elsewhere with both intakes and the Performer RPM with plenum divider notch v.nearly equalled the Victor Jr up top with some gains lower down. Likewise, there are plenty of people running Victor Jr intakes on street motors as they've found (on their combos) the Victor Jr still gives decent torque lower down. The only way to tell is to test on the dyno. And, FWIW, the guy who recommended this combo to me (the same guy that will be dynoing the engine and who has built hundreds of street and race motors) knows it's a 99% street-driven car and he specifically recommended the Victor Jr. intake as that's what he's seen make results with this combo on the dyno. I just want to try the Performer RPM as I've seen the dyno sheet from elsewhere that suggests it might be a touch better for me. We'll see.
And therein lies the usefulness of the dyno. If it were for nothing more than obtaining peak power numbers, hell, you can get a good estimate of that by running the quarter and use weight and trap speed. But being able to do back-to-back pulls w/variables limited to just an intake or just a carb or jet change is what really makes the money spent worthwhile, IMO.

I'm a bit curious about the Vic Jr. as compared to the Super Vic. I've heard around here from at least one member that the Vic Jr. is down on power compared to the S Vic in some cases, and I would wonder if yours is one of those cases- IF it's correct to assume this in the first place.

I asked why the Vic Jr was sometimes passed over in favor of the S Vic HERE. Take the info for whatever you think it's worth.
Reply With Quote Quick reply to this message
  #22 (permalink)  
Old 01-27-2011, 02:55 PM
Registered User
 
Last photo:
Join Date: Jul 2004
Location: At Speed
Age: 51
Posts: 1,446
Wiki Edits: 0

Thanks: 2
Thanked 52 Times in 49 Posts
For a street engine, the RPM will drive better regardless of some HP difference with the Vic that is only useful of the dyno. Dynos typically only test WOT performance.
Reply With Quote Quick reply to this message
  #23 (permalink)  
Old 01-27-2011, 03:24 PM
v8hed's Avatar
AK427
 
Last photo:
Join Date: May 2008
Location: Northampton, UK
Age: 40
Posts: 794
Wiki Edits: 0

Thanks: 1
Thanked 3 Times in 3 Posts
Quote:
Originally Posted by F-BIRD'88
If the open pressure does not exceed 320#, go with it. Only because you are on the dyno and the engine builder is controlling the break in. (if low ratio rockers are available go with those too.)
If the open pressure is more than this, remove the inner springs for the run in.
I'm not sure low ratio rockers are available, so I've decided to get some Comp 800-16 EDM lifters to replace the non-EDM 813-16 lifters I already have still sealed in the box. Will lose some money because of this, but it seems most folks have good luck with the EDM lifters.

Quote:
Originally Posted by F-BIRD'88
Adding a open spacer to the rpm manifold will show you the same effect as carving the center divider. (you won't have time for carving).
There are many benefits to leaving the center divider intact that you won;t se on the dyno.
The problem with running a spacer is hood clearance... I don't have too much. I might be able to fit a 1" spacer, but I wouldn't be able to run a 2". At least, not without a drop-base, slim air cleaner. In fact, thinking about it, a Victor Jr. may not even fit, which could be a deciding factor anyway! I've heard the CNC-ported 4-hole/open hybrid spacers are best? I've just got a regular 1" 4-hole phenolic spacer to try right now.

Interesting that you should point to negatives with notching the plenum divider, as the Performer RPM Air Gap comes with a notched divider from the factory and I haven't heard anyone complain about any aspect of the Air Gap's performance compared to the (un-notched) Performer RPM?


Quote:
Originally Posted by F-BIRD'88
I recommend this stuff. Apparently you can get it in the UK too.
www.molyslip.com
Yea, Molyslip has been arond for years over here. I still have a tube of Molyslip gear additive from at least 15 years back that I never got around to pouring into a manual trans. I've heard some horror stories about Molyslip though... think I'll just stick to a known FT-friendly oil with the appropriate ZDDP levels.

Last edited by v8hed; 01-27-2011 at 03:33 PM.
Reply With Quote Quick reply to this message
  #24 (permalink)  
Old 01-27-2011, 03:38 PM
v8hed's Avatar
AK427
 
Last photo:
Join Date: May 2008
Location: Northampton, UK
Age: 40
Posts: 794
Wiki Edits: 0

Thanks: 1
Thanked 3 Times in 3 Posts
Quote:
Originally Posted by ap72
So you've seen the RPM perform better on countless tests and you still want to test something else? Just look at the runner CSA, flow, and length, RPM has street written all over it, the Vic Jr is better suited to small ci circle track engines.

I'd run the RPM and forget about it, spend you time tweaking that combo with carb tuning, ignition tuning, and spacers. JMO though and its probably not worth $0.02.
Sonds like you're getting a little defensive... I'm simply going-on what my builder recommended. He knows full well this is a street motor and he swears the Victor Jr. is the ticket on this combo. THAT is why I want to try both. This guy knows all about CSA, flow, length and can recite formulas blind folded... he knows his stuff and has built hundreds of engines to prove it. I'm read good things about the Performer RPM though and, as I have one knocking around from my last engine, I may as well try both intakes and see how they behave. It's true, however, that the dyno can't test part-throttle performance or streetability and I have read this is an area that can cause a few headaches with a single plane intake, so I am personally swaying towards the Performer RPM if the dyno shows the 2 are close at WOT.
Reply With Quote Quick reply to this message
  #25 (permalink)  
Old 01-27-2011, 04:11 PM
Banned
 
Last photo:
Join Date: Jun 2005
Location: St. Louis, MO
Age: 29
Posts: 9,566
Wiki Edits: 0

Thanks: 20
Thanked 403 Times in 376 Posts
Quote:
Originally Posted by v8hed
Sonds like you're getting a little defensive... I'm simply going-on what my builder recommended. He knows full well this is a street motor and he swears the Victor Jr. is the ticket on this combo. THAT is why I want to try both. This guy knows all about CSA, flow, length and can recite formulas blind folded... he knows his stuff and has built hundreds of engines to prove it. I'm read good things about the Performer RPM though and, as I have one knocking around from my last engine, I may as well try both intakes and see how they behave. It's true, however, that the dyno can't test part-throttle performance or streetability and I have read this is an area that can cause a few headaches with a single plane intake, so I am personally swaying towards the Performer RPM if the dyno shows the 2 are close at WOT.
I'm not meaning to sound defensive, the victor jr just isn't a good intake for most people imo. Its usually bettered by the rpm or the supervic, across the board. Comparind those two for a dual purpose prostreet type engine would be of some value, I just don't wee why you would want to compare those two. The victor will lose out through 95% of the curve if not all. The open spacer on top is a usual trick and worth a look if you can get or borrow one, a lot of dyno shops have things like that to borrow and test.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
dyno sim whatsamotor Engine 4 05-20-2009 09:52 AM
Dyno 383 Lord_Hate Engine 34 07-29-2007 06:51 AM
Need a Dyno Silver00V6 Engine 3 03-28-2006 03:59 PM
dyno 78 chevy truck Engine 33 02-12-2004 07:46 AM
board etiquette rough draft Jon Hotrodders Site Suggestions and Help 29 02-27-2003 12:03 AM


All times are GMT -6. The time now is 10:29 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2015, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.