Stock engine basics

Alan Roehrich · 01-31-2011, 01:07 PM

What few people understand is that most Stock Eliminator cars are not fast just because of the engine. It's the entire car, and all the tuning and work that goes with it. The engine is important, don't get me wrong.

Most people can't take around 600HP in a 3300# car and run 9.90 with it in good air.

Danpa · 01-31-2011, 11:18 PM

Thanks so much for the responses! I feel I understand the class a little better now, much more going on behind the scenes than I realized. There is definately a lot more to it than a common weekend bracket car.

Some of the things that I'm planning for my motor are;

1.) balance the rotating assembly
2.) cc the heads
3.) port the heads, working to improve flow and velocity instead of just hogging out the ports.
4.) keeping the stock size valves or maybe a slight increase, again for velocity.
5.) 3 angle valve job
6.) match port everything
7.) keeping the stock carb (maybe??? don't know yet)
8.) headers, small tube
9.) stock compression

Just trying to make it the most efficient, make decent power without killing gas mileage.

What do you think? Am I on the right track? Missing anything obvious?

A few questions, though.

Does an increase in overlap work the same as higher lift on the cam. If it does, I guess you guys are limited on your lift, so you acomplish the same thing with overlap. Am I kind of right or COMPLETELY wrong?
Also, does an increase benefit torque or top end?

Again, thanks for everybodys patience with a new guy.

Dan

Larry Hill · 01-31-2011, 11:50 PM

Dan you can do all of your list and pick up power, remember hard smart work is what it takes. OR.....................

You can do what Mr. Bill did and get Shelby to change all the spec. 20 years later.

Most S/SS racers work very hard to use the power they make to turn the wheels.

Alan Roehrich · 02-01-2011, 12:14 AM

Dan,
Stock cams not only have a lot more duration and overlap than you'd want, but also a lot more aggressive lobe profile than you'd want in a street flat tappet cam.

Attention to detail is what makes Stock engines run.

Honestly, using a set of aftermarket heads with modern ports and combustion chambers will get you years ahead of what we're working with to make these older heaps go fast. The same thing with pistons, more efficient dish/dome profiles, better skirts, and better ring packages will be a lot cheaper and work better than what we run.

What you need to take away from the typical Stock program is the attention to detail and the blueprinting that allows us to make the most of the limited stuff we have. The use of torque plates, the perfect hone finish, the blueprinted locations of the deck, the main bearing bores, the lifter bores, the cylinder bores, and the exacting tolerances and clearances.

Richard Grant · 02-01-2011, 11:10 AM

Good answer, Alan

KingReptile · 02-01-2011, 11:31 AM

Terry's right enhanced is the word when I started racing in 96 my motor was a stock motor no stainless valves etc it made 280 horsepower.I have been asked the same question many times about how did i get that 283 to run so fast.One thing u have to consider is we have slicks and a lot of rear gear and spin these motors very high in RPM.For a stick car we have clutches u wouldnt want to run on the street,if you run an automatic u will have 3-4 torque convertors at $2000 a pop.

Danpa · 02-01-2011, 07:31 PM

Quote:

Originally Posted by KingReptile

Terry's right enhanced is the word when I started racing in 96 my motor was a stock motor no stainless valves etc it made 280 horsepower.I have been asked the same question many times about how did i get that 283 to run so fast.One thing u have to consider is we have slicks and a lot of rear gear and spin these motors very high in RPM.For a stick car we have clutches u wouldnt want to run on the street,if you run an automatic u will have 3-4 torque convertors at $2000 a pop.

I must be mistaken, but I thought most stock cams wouldn't let the motor rev very high, or at least make any power while doing it. Don't they kind of fall on their face above 5 or 6 grand? Am I wrong?

Chris Barnes · 02-04-2011, 05:44 PM

Drag racing engines in general conform to a different set of standards than street motors. We had a stocker style bracket motor (440) that went through at least three different cars and four seasons of abuse. It was one of those "built in the dirt" motors that just refuse to die. It was running mid elevens in a 3600 pound car the day that it spit out a rod bearing. We were amazed and a little proud of that thing. Then I started thinking, if it had been in a street car it would have died before it got started on it's fifth tank of gas! Granted, you aren't going to shift at 5500 rpm in your street car but still I like the idea of using current state of the art stuff like heads, pistons, and a roller cam and painting it up to look old.

Also, I totally agree that the motor is but one piece of the stocker equation. Weight distribution, suspension set up, alignment, chassis reinforcement etc are equally important.

Good luck!

Chris Barnes
Wagons of Steel
Stock 6621

01-31-2011, 01:07 PM	#1
Alan Roehrich Veteran Member Join Date: May 2006 Location: Murfreesboro TN Posts: 5,132 Likes: 1,596 Liked 1,910 Times in 428 Posts	Re: Stock engine basics What few people understand is that most Stock Eliminator cars are not fast just because of the engine. It's the entire car, and all the tuning and work that goes with it. The engine is important, don't get me wrong. Most people can't take around 600HP in a 3300# car and run 9.90 with it in good air. __________________ Alan Roehrich 212A G/S

01-31-2011, 11:18 PM	#2
Danpa Junior Member Join Date: Jan 2011 Posts: 4 Likes: 0 Liked 0 Times in 0 Posts	Re: Stock engine basics Thanks so much for the responses! I feel I understand the class a little better now, much more going on behind the scenes than I realized. There is definately a lot more to it than a common weekend bracket car. Some of the things that I'm planning for my motor are; 1.) balance the rotating assembly 2.) cc the heads 3.) port the heads, working to improve flow and velocity instead of just hogging out the ports. 4.) keeping the stock size valves or maybe a slight increase, again for velocity. 5.) 3 angle valve job 6.) match port everything 7.) keeping the stock carb (maybe??? don't know yet) 8.) headers, small tube 9.) stock compression Just trying to make it the most efficient, make decent power without killing gas mileage. What do you think? Am I on the right track? Missing anything obvious? A few questions, though. Does an increase in overlap work the same as higher lift on the cam. If it does, I guess you guys are limited on your lift, so you acomplish the same thing with overlap. Am I kind of right or COMPLETELY wrong? Also, does an increase benefit torque or top end? Again, thanks for everybodys patience with a new guy. Dan

01-31-2011, 11:50 PM	#3
Larry Hill Live Reporter Join Date: Oct 2004 Location: Hickory, Ky Posts: 10,669 Likes: 1,967 Liked 10,852 Times in 2,254 Posts	Re: Stock engine basics Dan you can do all of your list and pick up power, remember hard smart work is what it takes. OR..................... You can do what Mr. Bill did and get Shelby to change all the spec. 20 years later. Most S/SS racers work very hard to use the power they make to turn the wheels. __________________ IHM Used Parts https://ihmusedparts.com 888-821-1817

02-01-2011, 12:14 AM	#4
Alan Roehrich Veteran Member Join Date: May 2006 Location: Murfreesboro TN Posts: 5,132 Likes: 1,596 Liked 1,910 Times in 428 Posts	Re: Stock engine basics Dan, Stock cams not only have a lot more duration and overlap than you'd want, but also a lot more aggressive lobe profile than you'd want in a street flat tappet cam. Attention to detail is what makes Stock engines run. Honestly, using a set of aftermarket heads with modern ports and combustion chambers will get you years ahead of what we're working with to make these older heaps go fast. The same thing with pistons, more efficient dish/dome profiles, better skirts, and better ring packages will be a lot cheaper and work better than what we run. What you need to take away from the typical Stock program is the attention to detail and the blueprinting that allows us to make the most of the limited stuff we have. The use of torque plates, the perfect hone finish, the blueprinted locations of the deck, the main bearing bores, the lifter bores, the cylinder bores, and the exacting tolerances and clearances. __________________ Alan Roehrich 212A G/S

02-01-2011, 11:10 AM	#5
Richard Grant Member Join Date: Jan 2002 Location: West Monroe, La. Posts: 301 Likes: 9 Liked 13 Times in 7 Posts	Re: Stock engine basics Good answer, Alan __________________ Richard Grant 4988 STK

02-01-2011, 11:31 AM	#6
KingReptile Member Join Date: Mar 2008 Posts: 257 Likes: 0 Liked 0 Times in 0 Posts	Re: Stock engine basics Terry's right enhanced is the word when I started racing in 96 my motor was a stock motor no stainless valves etc it made 280 horsepower.I have been asked the same question many times about how did i get that 283 to run so fast.One thing u have to consider is we have slicks and a lot of rear gear and spin these motors very high in RPM.For a stick car we have clutches u wouldnt want to run on the street,if you run an automatic u will have 3-4 torque convertors at $2000 a pop.

02-04-2011, 05:44 PM	#8
Chris Barnes Member Join Date: Nov 2010 Posts: 139 Likes: 0 Liked 0 Times in 0 Posts	Re: Stock engine basics Drag racing engines in general conform to a different set of standards than street motors. We had a stocker style bracket motor (440) that went through at least three different cars and four seasons of abuse. It was one of those "built in the dirt" motors that just refuse to die. It was running mid elevens in a 3600 pound car the day that it spit out a rod bearing. We were amazed and a little proud of that thing. Then I started thinking, if it had been in a street car it would have died before it got started on it's fifth tank of gas! Granted, you aren't going to shift at 5500 rpm in your street car but still I like the idea of using current state of the art stuff like heads, pistons, and a roller cam and painting it up to look old. Also, I totally agree that the motor is but one piece of the stocker equation. Weight distribution, suspension set up, alignment, chassis reinforcement etc are equally important. Good luck! Chris Barnes Wagons of Steel Stock 6621