Edelbrock RPM heads 498 dyno Test - Chevelle Tech
Performance Our High Performance area

 27Likes
Reply
 
LinkBack Thread Tools Search this Thread Display Modes
post #1 of 18 (permalink) Old Aug 3rd, 17, 1:05 PM Thread Starter
Tech Team
Pete
 
Join Date: Aug 2012
Location: Janesville Wi
Posts: 405
Garage
Edelbrock RPM heads 498 dyno Test

I had a customer bring me his Edelbrock headed 496 for an overheating and oil usage issue, and to remove the solid roller camshaft and heavy valve springs to replace with a hydraulic roller camshaft.

Upon teardown several issues were evident, and some not so evident. Missing coolant holes and poor cylinder finish, along with a block that hadn’t been clearanced, and 6 of the 8 rods were just rubbing the block. The block also had main and head studs installed, but had not been lined honed, decked, or honed with a torque plate.

The owner also proceeded to tell me how the machine shop had failed to balance the crank properly and had given him external balance flexplate and dampener. It was a real shaker when he installed it. I later discovered the counterweights were not cut properly, and would not clear the pistons, and had been hitting 2 of the JE pistons. Another reminder of why I quit using Eagle products 16 years ago.

After an assessment of his parts, which consisted of RPM AG intake, 290cc Oval RPM 6045 heads (113cc), JE flat top pistons (8.8:1 CR), Eagle H beam 6.385” rods and 4.250” steel crank, Lunati 244°/244° @ .050” SR camshaft, I laid out a plan of action for some changes to improve his situation.

The Edelbrock heads received a valve job and some minor bowl work, and chamber blending. I had RaceTec make me a set of 4032 pistons with a 16cc dome and 1.5/3.0mm ring set, for a final CR of 10.4:1. A Howards Cams shelf cam was selected with Howards/Morel 91167 lifters. Cam specs are HR#120265-10 SADI core 237/243 @ .050, 289/295 Advertised, 110 LSA, 106 ICL, .373/.377 lobes, .635/.640 lift. Manton 3/8” pushrods were used with PSI springs.

I tested both the customers QFT 850 VS and QFT 1050 AN with 1” open spacer, 35° total timing on BP 93 octane with 10% Ethanol, 2” x 3.5” dyno headers. Engine idles at 950rpm with 11-12” of vacuum. The 1050 was worth another 10/10 HP/TQ over the 850VS.

This was the first time I’ve used these heads, so I was interested to see how they compared to similar setups.
Dyno videos-
Attached Thumbnails
Click image for larger version

Name:	GK 496 Edelbrock heads dyno.jpg
Views:	180
Size:	116.8 KB
ID:	463673   Click image for larger version

Name:	GK 496  #6 STP Values w avgs.JPG
Views:	382
Size:	131.2 KB
ID:	463681   Click image for larger version

Name:	GK 496  #6 Graph website.jpg
Views:	311
Size:	90.3 KB
ID:	463689  

CP Motorworks,Inc

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Custom Performance Engines &
Cylinder Head Fixtures for Vertical Mills and Surfacing Machines

1971 Chevelle 406- Mine
1970 Chevelle 496- 10.2:1, 781 ovals, 3.31, 275/60 DR 3800lbs, [email protected] on 91 octane - Hers
CPMotorworks is offline  
Sponsored Links
Advertisement
 
post #2 of 18 (permalink) Old Aug 3rd, 17, 6:38 PM
Tech Team
 
Join Date: Feb 2006
Location: Melbourne, Australia
Posts: 630
Re: Edelbrock RPM heads 498 dyno Test

I had those same 60459 heads on my 454 with a Crane SFT 134781 248°/258°@.050" and Victor Jnr. The comp was 12:1 with a set of Ross custom "Edelbrock dome" pistons to suit the unique Edelbrock chambers.
Through a Powerglide and 9", it made a corrected 510hp at the wheels on a Dynapack dyno and ran 122mph at the track in a 3660lb Camaro.

Although now 20 year old technology, I quite like these heads for what they are but feel that they aren't capable of more than ~650hp. Not that I am any expert..
I later installed a Crane SR 138101 254°/262°@.050 and it made a lame 570hp on an engine dyno.
Discussions with Mike Lewis and also Larry Meaux indicated to me that I had reached a "choke point" with these heads in terms of flow.
In other words, I'd outgrown them with that roller cam and was going backwards.
(A later switch to a very similar sized 300cc modern port AFR head, and dropping comp to 11:1 made +140hp with a Crane 138101 262°/272°@.050".)
CPMotorworks likes this.

Post pictures.. -or it never happened!
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
BlackoutSteve is offline  
post #3 of 18 (permalink) Old Aug 3rd, 17, 10:12 PM
Lifetime Premium Member
Rod
 
Join Date: Nov 1999
Location: Western MA
Posts: 3,708
Re: Edelbrock RPM heads 498 dyno Test

Thanks for sharing this. I enjoy your posts.

Makes you wonder about the people out there passing themselves off as engine builders or engine machinists.
shovelrick and CPMotorworks like this.
Rmchevelle is offline  
 
post #4 of 18 (permalink) Old Aug 4th, 17, 12:54 AM
Senior Tech Team
 
Join Date: Nov 2003
Location: NORTH EAST
Posts: 3,330
Re: Edelbrock RPM heads 498 dyno Test

Quote:
Originally Posted by Rmchevelle View Post
Thanks for sharing this. I enjoy your posts.

Makes you wonder about the people out there passing themselves off as engine builders or engine machinists.

I see a lot of wannabe machinist and shops out there using make believe cylinder hones, no plate honing, poor balance jobs, poor over all machine work, On My F/B page you can see some of the issues I deal with daily.

https://www.facebook.com/cncblocks.northeast
blue_69_malibu likes this.

Website is up and running

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Machine shop tour

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Monthly Specials

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
CNC BLOCKS N/E is online now  
post #5 of 18 (permalink) Old Aug 4th, 17, 5:51 AM
Lifetime Premium Member
jimmyradford
 
Join Date: Oct 2007
Location: ARKLATEX
Posts: 2,677
Re: Edelbrock RPM heads 498 dyno Test

Nice job on the new build.
CPMotorworks likes this.

TC Member # 4431
'07.5 Chevrolet 2500HD-6.6 D-Max
'02 Ford Excursion-7.3 PSD
'67 Chevrolet Biscayne- BB 427/TH400/10 bolt (Hers)
'67 Hell Camino-BB 427/TH400/4.10 (His)

"Good people sleep peacefully in their beds at night only because rough men stand ready to do violence on their behalf."-Orsen Wells

Strong people are harder to kill than weak people. And they are more useful in general.
badrad is online now  
post #6 of 18 (permalink) Old Aug 4th, 17, 10:42 AM
Lifetime Premium Member
Dan
 
Join Date: Aug 2007
Location: orange county
Posts: 9,935
Re: Edelbrock RPM heads 498 dyno Test

The little Edelbrock heads can make power. I have a pair of Performers (6048)
on my 500 incher. Performed quite well with a Isky Solid Flat Tappet. Still capable after many many years.
CPMotorworks likes this.

'66 SS Chevelle
565 BBC Mamofied 300cc Ovals
4.11 12 bolt
Best e.t. to date [email protected] @115.31
1.315 60'
Stokerboats is offline  
post #7 of 18 (permalink) Old Aug 4th, 17, 10:59 AM
 
Join Date: Dec 2005
Location: Tri-Cities
Posts: 8,791
Re: Edelbrock RPM heads 498 dyno Test

Quote:
Originally Posted by CPMotorworks View Post
I had a customer bring me his Edelbrock headed 496 for an overheating and oil usage issue, and to remove the solid roller camshaft and heavy valve springs to replace with a hydraulic roller camshaft.

Upon teardown several issues were evident, and some not so evident. Missing coolant holes and poor cylinder finish, along with a block that hadn’t been clearanced, and 6 of the 8 rods were just rubbing the block. The block also had main and head studs installed, but had not been lined honed, decked, or honed with a torque plate.

The owner also proceeded to tell me how the machine shop had failed to balance the crank properly and had given him external balance flexplate and dampener. It was a real shaker when he installed it. I later discovered the counterweights were not cut properly, and would not clear the pistons, and had been hitting 2 of the JE pistons. Another reminder of why I quit using Eagle products 16 years ago.

After an assessment of his parts, which consisted of RPM AG intake, 290cc Oval RPM 6045 heads (113cc), JE flat top pistons (8.8:1 CR), Eagle H beam 6.385” rods and 4.250” steel crank, Lunati 244°/244° @ .050” SR camshaft, I laid out a plan of action for some changes to improve his situation.

The Edelbrock heads received a valve job and some minor bowl work, and chamber blending. I had RaceTec make me a set of 4032 pistons with a 16cc dome and 1.5/3.0mm ring set, for a final CR of 10.4:1. A Howards Cams shelf cam was selected with Howards/Morel 91167 lifters. Cam specs are HR#120265-10 SADI core 237/243 @ .050, 289/295 Advertised, 110 LSA, 106 ICL, .373/.377 lobes, .635/.640 lift. Manton 3/8” pushrods were used with PSI springs.

I tested both the customers QFT 850 VS and QFT 1050 AN with 1” open spacer, 35° total timing on BP 93 octane with 10% Ethanol, 2” x 3.5” dyno headers. Engine idles at 950rpm with 11-12” of vacuum. The 1050 was worth another 10/10 HP/TQ over the 850VS.

This was the first time I’ve used these heads, so I was interested to see how they compared to similar setups.
Dyno videos-
498 Edelbrock Dyno Test 627HP CPMotorworks - YouTube
498 Dyno test Edelbrock Oval heads CPMotorworks - YouTube
Very nice powerband Pete. Solid build sir.
CPMotorworks likes this.

Chris Straub
Mfg Performance Parts

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


Why is it we never have time or money to do it the right way in the beginning but we always have time and money to do it over again?
cstraub is offline  
post #8 of 18 (permalink) Old Aug 4th, 17, 11:14 AM
Lifetime Premium Member
Jeff
 
Join Date: Feb 2008
Location: PuebloWest, CO.
Posts: 6,079
Re: Edelbrock RPM heads 498 dyno Test

very nice I have a set of the edelbrock 60449 I want to put on my 402 with the 174 mini blower. we will see how that works.

78 Malibu, 402, th350, holley sniper EFI, 9" 3:70, Hoosier 26X8.50-15 slicks.
69 VW baja 1600cc.
96 chevy 1500, tow vehicle.
03 yz85 fun bike.
Jebchevelle is offline  
post #9 of 18 (permalink) Old Aug 4th, 17, 11:50 AM
Senior Tech Team
 
Join Date: Nov 2003
Location: NORTH EAST
Posts: 3,330
Re: Edelbrock RPM heads 498 dyno Test

Quote:
Originally Posted by CPMotorworks View Post
I had a customer bring me his Edelbrock headed 496 for an overheating and oil usage issue, and to remove the solid roller camshaft and heavy valve springs to replace with a hydraulic roller camshaft.

Upon teardown several issues were evident, and some not so evident. Missing coolant holes and poor cylinder finish, along with a block that hadn’t been clearanced, and 6 of the 8 rods were just rubbing the block. The block also had main and head studs installed, but had not been lined honed, decked, or honed with a torque plate.

The owner also proceeded to tell me how the machine shop had failed to balance the crank properly and had given him external balance flexplate and dampener. It was a real shaker when he installed it. I later discovered the counterweights were not cut properly, and would not clear the pistons, and had been hitting 2 of the JE pistons. Another reminder of why I quit using Eagle products 16 years ago.

After an assessment of his parts, which consisted of RPM AG intake, 290cc Oval RPM 6045 heads (113cc), JE flat top pistons (8.8:1 CR), Eagle H beam 6.385” rods and 4.250” steel crank, Lunati 244°/244° @ .050” SR camshaft, I laid out a plan of action for some changes to improve his situation.

The Edelbrock heads received a valve job and some minor bowl work, and chamber blending. I had RaceTec make me a set of 4032 pistons with a 16cc dome and 1.5/3.0mm ring set, for a final CR of 10.4:1. A Howards Cams shelf cam was selected with Howards/Morel 91167 lifters. Cam specs are HR#120265-10 SADI core 237/243 @ .050, 289/295 Advertised, 110 LSA, 106 ICL, .373/.377 lobes, .635/.640 lift. Manton 3/8” pushrods were used with PSI springs.

I tested both the customers QFT 850 VS and QFT 1050 AN with 1” open spacer, 35° total timing on BP 93 octane with 10% Ethanol, 2” x 3.5” dyno headers. Engine idles at 950rpm with 11-12” of vacuum. The 1050 was worth another 10/10 HP/TQ over the 850VS.

This was the first time I’ve used these heads, so I was interested to see how they compared to similar setups.
Dyno videos-
498 Edelbrock Dyno Test 627HP CPMotorworks - YouTube
498 Dyno test Edelbrock Oval heads CPMotorworks - YouTube

Out standing job the customer should be real happy this build.

Website is up and running

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Machine shop tour

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Monthly Specials

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
CNC BLOCKS N/E is online now  
post #10 of 18 (permalink) Old Aug 4th, 17, 11:59 PM Thread Starter
Tech Team
Pete
 
Join Date: Aug 2012
Location: Janesville Wi
Posts: 405
Garage
Re: Edelbrock RPM heads 498 dyno Test

Quote:
Originally Posted by BlackoutSteve View Post
I had those same 60459 heads on my 454 with a Crane SFT 134781 248°/258°@.050" and Victor Jnr. The comp was 12:1 with a set of Ross custom "Edelbrock dome" pistons to suit the unique Edelbrock chambers.
Through a Powerglide and 9", it made a corrected 510hp at the wheels on a Dynapack dyno and ran 122mph at the track in a 3660lb Camaro.

Although now 20 year old technology, I quite like these heads for what they are but feel that they aren't capable of more than ~650hp. Not that I am any expert..
I later installed a Crane SR 138101 254°/262°@.050 and it made a lame 570hp on an engine dyno.
Discussions with Mike Lewis and also Larry Meaux indicated to me that I had reached a "choke point" with these heads in terms of flow.
In other words, I'd outgrown them with that roller cam and was going backwards.
(A later switch to a very similar sized 300cc modern port AFR head, and dropping comp to 11:1 made +140hp with a Crane 138101 262°/272°@.050".)
In stock form they are limited for sure. With some work I can see some room for improvement, but at what point is it money better spent on a head with a better design basis.

Quote:
Originally Posted by Rmchevelle View Post
Thanks for sharing this. I enjoy your posts.

Makes you wonder about the people out there passing themselves off as engine builders or engine machinists.
Thanks, I thought it was interesting to see what it made for power. Very similar to another 489 with mildly ported 781 heads I did about 4 years ago for a member here. This should be very driveable for the owner, it's going in a Pro Street style 1967 Camaro with 3.50 gears and 33" MTs.
I think it highlights the difference from your average engine machine shop, with general knowledge of several engines and basic procedures verses the shops that build a combination specifically suited to each customers needs and vehicle use.

Quote:
Originally Posted by cstraub View Post
Very nice powerband Pete. Solid build sir.
Quote:
Originally Posted by CNC BLOCKS N/E View Post
Out standing job the customer should be real happy this build.
Thanks Guys!

CP Motorworks,Inc

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Custom Performance Engines &
Cylinder Head Fixtures for Vertical Mills and Surfacing Machines

1971 Chevelle 406- Mine
1970 Chevelle 496- 10.2:1, 781 ovals, 3.31, 275/60 DR 3800lbs, [email protected] on 91 octane - Hers
CPMotorworks is offline  
post #11 of 18 (permalink) Old Aug 5th, 17, 12:21 AM
Lifetime Premium Member
Dan
 
Join Date: Aug 2007
Location: orange county
Posts: 9,935
Re: Edelbrock RPM heads 498 dyno Test

Quote:
Originally Posted by BlackoutSteve View Post
I had those same 60459 heads on my 454 with a Crane SFT 134781 248°/258°@.050" and Victor Jnr. The comp was 12:1 with a set of Ross custom "Edelbrock dome" pistons to suit the unique Edelbrock chambers.
Through a Powerglide and 9", it made a corrected 510hp at the wheels on a Dynapack dyno and ran 122mph at the track in a 3660lb Camaro.

Although now 20 year old technology, I quite like these heads for what they are but feel that they aren't capable of more than ~650hp. Not that I am any expert..
I later installed a Crane SR 138101 254°/262°@.050 and it made a lame 570hp on an engine dyno.
Discussions with Mike Lewis and also Larry Meaux indicated to me that I had reached a "choke point" with these heads in terms of flow.
In other words, I'd outgrown them with that roller cam and was going backwards.
(A later switch to a very similar sized 300cc modern port AFR head, and dropping comp to 11:1 made +140hp with a Crane 138101 262°/272°@.050".)
My old Edelbrocks did very well on my 500 incher at 11 to 1 comp. Fairly sure it made north of 650hp. I used the manifold and carb from that engine on my current 565.
CPMotorworks likes this.

'66 SS Chevelle
565 BBC Mamofied 300cc Ovals
4.11 12 bolt
Best e.t. to date [email protected] @115.31
1.315 60'
Stokerboats is offline  
post #12 of 18 (permalink) Old Aug 5th, 17, 1:40 AM
Lifetime Premium Member
Mike
 
Join Date: Apr 2003
Location: Mendocino County, Northern CA
Posts: 12,886
Re: Edelbrock RPM heads 498 dyno Test

Very nice Pete, really enjoy your write-ups & attention to detail
Stokerboats and CPMotorworks like this.

Mike (Wolfplace)
VISIT US AT

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
+4axis CNC block machining+
================================
Welcome to the internet,,, "Experts" made daily
===
"Life is tough.,, Life is even tougher if you're stupid."
----John Wayne----


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Wolfplace is offline  
post #13 of 18 (permalink) Old Aug 5th, 17, 6:29 AM
Tech Team
 
Join Date: Feb 2006
Location: Melbourne, Australia
Posts: 630
Re: Edelbrock RPM heads 498 dyno Test

Quote:
Originally Posted by Stokerboats View Post
My old Edelbrocks did very well on my 500 incher at 11 to 1 comp. Fairly sure it made north of 650hp. I used the manifold and carb from that engine on my current 565.
Quite possible Dan. 650 is just a guess but I certainly wouldn't be expecting 700.
I reckon with my 510 RWHP with the flat tappet, I was probably on 600-620 at the engine.
Great head in it's day.

Post pictures.. -or it never happened!
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
BlackoutSteve is offline  
post #14 of 18 (permalink) Old Aug 5th, 17, 12:07 PM
Lifetime Premium Member
Dan
 
Join Date: Aug 2007
Location: orange county
Posts: 9,935
Re: Edelbrock RPM heads 498 dyno Test

The OP's build is fairly straight forward and not wildly radical. This is a dependable build with a happy owner once it is installed.
CPMotorworks likes this.

'66 SS Chevelle
565 BBC Mamofied 300cc Ovals
4.11 12 bolt
Best e.t. to date [email protected] @115.31
1.315 60'
Stokerboats is offline  
post #15 of 18 (permalink) Old Aug 6th, 17, 1:27 PM
Senior Tech Team
Vince
 
Join Date: Jun 2003
Location: Thornton, Pa
Posts: 13,503
Re: Edelbrock RPM heads 498 dyno Test

They say flow #'s aren't everything and inbelieve it as I had a set of eddys out perform a much more expensive head on a 454. Great head imo for the street.
CPMotorworks likes this.

*69 SS 502 EFI /224* HR/9.8:1/T56/3.90 11.5/124mph
*11 C6, 6.2, 6spd
*96 Stang 6.0 turbo 10.5/135mph
*2011 Mustang GT premium
*61" Scag Kohler 22hp 7mph
69-CHVL is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Chevelle Tech forums, you must first register.
Please enter your desired user 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. Note, you will be sent a confirmation request to this address.

Email Address:
OR

Log-in










Thread Tools Search this Thread
Show Printable Version Show Printable Version
Email this Page Email this Page
Search this Thread:

Advanced Search
Display Modes
Linear Mode Linear Mode



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

 
For the best viewing experience please update your browser to Google Chrome