Mild 454 Engine Build
Thread Starter
Racer
Joined: Aug 2011
Posts: 493
Likes: 217
Mild 454 Engine Build
I thought I'd share a recent 454 build with your forum. Built for a 1971 Corvette, although not a correct restoration type build but a every day driver build. Compression turned out right around 9.4 along with a 228 @ .050 hyd roller, A 781 oval port head was used with a 2.190/1.880 valve. The factory cast iron intake was used with a Q-Jet. It will be interesting to see what kind of power this type of build will make for power, I will follow up with a dyno test. Some pictures.
Drifting
Joined: Jan 2014
Posts: 1,866
Likes: 140
From: Sadieville Kentucky
I thought I'd share a recent 454 build with your forum. Built for a 1971 Corvette, although not a correct restoration type build but a every day driver build. Compression turned out right around 9.4 along with a 228 @ .050 hyd roller, A 781 oval port head was used with a 2.190/1.880 valve. The factory cast iron intake was used with a Q-Jet. It will be interesting to see what kind of power this type of build will make for power, I will follow up with a dyno test. Some pictures.
Hi
First of all I wish you would clean up you shop lol. Let me know how it comes out I am getting ready t rebuild my 454 same year '71 a Quadra jet will work fine may need to change metering rods .
Merry Christmas
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Thread Starter
Racer
Joined: Aug 2011
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Burning Brakes
Joined: Jul 2015
Posts: 823
Likes: 57
From: Austin TX
It's much more difficult to tune a Q-jet than a Holley or Edelbrock. I know this from experience with my own '72 and '73 454 Vettes. The Q-jet can be an excellent carb, but you'll be many hours ahead if you start with something else (Holley is the easiest, although the Edelbrock tune kits make theirs a close second). Contrary to popular opinion, 600-650 CFM is NOT too small for a BB on the street. Calculate the flow through the motor at 4,000-5,000 RPM (and compensate for average volumetric efficiency) and you'll see what I mean. Street acceleration with a carb this size can be truly amazing, I used to pull the front wheels off the ground. A larger carb won't meter as well at lower RPM, will cost you torque and fuel mileage. Speaking of which, a 650 double-pumper will really get your attention on a motor like this, but fuel mileage will suffer quite a bit compared to a vacuum secondary carb.
Have fun!
Have fun!
Race Director
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From: Corsicana, Tx
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Contrary to popular opinion, 600-650 CFM is NOT too small for a BB on the street. Calculate the flow through the motor at 4,000-5,000 RPM (and compensate for average volumetric efficiency) and you'll see what I mean. Street acceleration with a carb this size can be truly amazing, I used to pull the front wheels off the ground. A larger carb won't meter as well at lower RPM, will cost you torque and fuel mileage. Speaking of which, a 650 double-pumper will really get your attention on a motor like this, but fuel mileage will suffer quite a bit compared to a vacuum secondary carb.
Have fun!
Have fun!
If you're never going over 5000 RPM...maybe a 650 is sorta OK....but I'd use 750+ cfm all day long...especially on a dual plane intake on a motor that has better heads and cam for sure.
When going WOT an individual cylinder...and the rapidly following next ones with a dual plane only "sees" 2 BBLs vs a single plane that has access to all 4.
I'm betting on the capability for an 11 sec time slip in the right C-3.
JIM
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
I say about 360-370 horsepower....420 ft/lbs. torque....the low rise intake is a HP killer.....
Please do not use a square bore carb on a Q-Jet manifold.....even the best spacers have a horrible mismatch that not only is detrimental to flow....but wreaks havoc on tuning....
It should run great with a Q-jet.....you will have a lot of fun with it.....lots of torque down low
Jebby
Please do not use a square bore carb on a Q-Jet manifold.....even the best spacers have a horrible mismatch that not only is detrimental to flow....but wreaks havoc on tuning....
It should run great with a Q-jet.....you will have a lot of fun with it.....lots of torque down low
Jebby
Last edited by Jebbysan; Dec 21, 2015 at 11:32 AM.
Le Mans Master
Joined: Mar 2001
Posts: 6,239
Likes: 1,010
From: Watkinsville, GA and Glen Cove, NY
I say about 360-370 horsepower....420 ft/lbs. torque....the low rise intake is a HP killer.....
Please do not use a square bore carb on a Q-Jet manifold.....even the best spacers have a horrible mismatch that not only is detrimental to flow....but wreaks havoc on tuning....
It should run great with a Q-jet.....you will have a lot of fun with it.....lots of torque down low
Jebby
Please do not use a square bore carb on a Q-Jet manifold.....even the best spacers have a horrible mismatch that not only is detrimental to flow....but wreaks havoc on tuning....
It should run great with a Q-jet.....you will have a lot of fun with it.....lots of torque down low
Jebby
Last edited by 69ttop502; Dec 21, 2015 at 11:39 AM.
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
Jebby, if you are not familiar with Mark (Vortecpro), he is a fantastic engine builder that always seems to do way better than the sum of his parts lol. He works magic on the old oval port heads though not sure he worked his magic on this build. Will be interesting to see.��
Jebby
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
I guess I am a professional engine builder myself......with a reputation for building phenomenal Big Blocks....but it just didn't pay...and I got older.....still love building engines...just not for a living.....
My hats off to Mr. Mark for putting together what I am sure is a fine Mark 4
...now for that dyno sheet Jebby
Burning Brakes
Joined: Feb 2014
Posts: 1,045
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From: Cape Neddick Maine
2020 C3 of the Year Finalist - Modified
too funny I need to watch this post I am interested to see his FWHP should be a good eye opener for some.
Mark does really nice work ive heard of him once or twice.
I need to watch this post I am interested to see his FWHP should be a good eye opener for some.Mark does really nice work ive heard of him once or twice.
Burning Brakes
Joined: Jul 2015
Posts: 823
Likes: 57
From: Austin TX
If not for the thieves that put me out of business, I would have had a twin-turbo 454 Vette on the street back in '77. The hot-rod hobby attracts a lot of despicable people, I learned that the hard way when I was young and stupid. Anyway, I'm hoping the OP will post progress and results for this build. It's amazing what a near-stock BB can do in the right hands!
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
Hey, the big blocks I've built were phenomenal too! If not for the thieves that put me out of business, I would have had a twin-turbo 454 Vette on the street back in '77. The hot-rod hobby attracts a lot of despicable people, I learned that the hard way when I was young and stupid. Anyway, I'm hoping the OP will post progress and results for this build. It's amazing what a near-stock BB can do in the right hands!
If not for the thieves that put me out of business, I would have had a twin-turbo 454 Vette on the street back in '77. The hot-rod hobby attracts a lot of despicable people, I learned that the hard way when I was young and stupid. Anyway, I'm hoping the OP will post progress and results for this build. It's amazing what a near-stock BB can do in the right hands!One of my mentors....built IHRA Top Stock engines....talk about dirty tricks!
Yes...popcorn on the OP.....I am probably way off.....
Jebby