Stock engine basics
 

I have always been amazed at the amount of horsepower Stock Eliminator racers have been able to extract from their cars. I would think that the engines must be extremely efficient, squeezing the last bit of hp from every drop of fuel.
My question is, what do you guys do to the engines to make them run so strong on seemingly mundane parts?
I realize some basics like fully balanced rotating assembly and cc' ing the heads would help, but what else?
I'd like to apply some of the things to my street engine when I rebuild it.

Thanks,

Dan

Re: Stock engine basics
 

I know you are looking for a somewhat honest answer here but I will leave that for another to answer. A lot of the combos are....shall we say "Enhanced" to the limit and in a lot of cases beyond. They would make a poor STREET engine. The cams are way to radical, the spring pressures are way to high and the piston rings would not seal for very long in everyday street use. Not to mention the operating range (RPM's) they are twisted to with 5.13-5:38 and up rear gearing. You would not be happy with this type of rear gearing in an everyday street car. Its a combination of precision machine work, careful assembly, and picking the right combo to begin with. On the street you are stuck with pump gas (no lead) and lower compression ratio's. Use a stroker kit for your brand of engine and go for torque to run on todays junk gas and you will be happier for it. If you want to fool your buddies just make the engine "LOOK" stock on the outside.

Re: Stock engine basics
 

Very valid and good question. Probably the most important is NEVER overlook details. The factories have so many imperfections in some of the smallest areas where improvements can yield some surprising results. Also, remember the car itself. There are many areas where you can improve performance in suspension, weight transfer, and hp robbing rotating weight.

I was talking to another racer yesterday about the very same subject. Too many racers looking to go fast fail to look at the most basic areas. I'm sure there will be others that chime in on this subject and should offer some interesting answers.

Re: Stock engine basics
 

X-TECH MAN is right on, for the street it's hard to beat stroker motors that remain pump gas friendly. Correct clearances, file your ring end gaps, etc. are essential and let a good shop bore/hone your block. Also, given the tighter convertors (you do NOT want a "stocker" convertor on the street any more than you want 5:13's) cam selection is absolutely critical. Don't catalog shop, talk to one of the reputable cam makers and tailor the cam to your combo. Finally, get all the weight out of your car that's practical, it pays dividends in every area of car performance.

P.S. Crate motors are a pretty good deal but again selection is key and cubic inches rule. If you decide to go crate motor then start a new thread soliciting feedback, there is a wealth of knowledge on this forum. Also helpful to indicate your current car/motor. Every make has it's own following.

Re: Stock engine basics
 

I think what he's looking for is how to apply some Stock Eliminator technology to a street engine, not building a class motor for the street per-se. There are a lot of good practices to get in the habit of doing when prepping a motor. Many are no nonsense basics that are often overlooked. When I was in tech school 30 years ago we took a tired Olds 350 that was burning coolant and oil past the rings and guides. While other students completed rebuilds on their projects much quicker than my group, we simply took the time to ensure everything was matched, head cc's were the same, proper clearances, tightly sealed chambers, etc. The result was a tire frying engine that certainly produced more power than it did from the factory, with no aftermarket parts whatsoever.

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.

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

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.

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.

Re: Stock engine basics
 

Good answer, Alan

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.

Re: Stock engine basics
 

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?

Re: Stock engine basics
 

"Stocker" cams are far different than a stock production camshaft. They typically have 50 or more degrees of duration @ .050. than an OEM cam would. Many of these stocker engines turn rpm in excess of 7500,don't try that with most OE cam profiles.

Re: Stock engine basics
 

Even before the lifter rule, valve spring rule, and camshaft duration rule were all rescinded, the "cheater" camshafts for Stock were fairly "square" with regards to lobe design. These days the only thing stock about a Stock camshaft is the tappet lift.

Re: Stock engine basics
 

Danpa, it's not just the power that's made, although the process of perfecting every part of the engine combination, and maximizing each one within the rules to make 100hp more than the factory engine is a big piece of the performance. In stock, EVERY part of the car is looked at to maximize straight line acceleration, no compromises, and very often no expense spared. The thinking behind the modifications and the systematic approach to increasing performance would apply well to a street car when you begin to tinker with it, but most of the parts that are used in a stocker would not be acceptable in a street car by far. To best achieve your goals, a lengthy discussion with a knowledgeable car/engine builder will pay big dividends down the road, to recommend the proper combination of parts and modifications to work for you (and your budget). If you modify just the engine, you're falling short of the best approach for street performance, the whole car needs to be considered, and many improvements can come at little cost. Knowing the best parts/mods for your "bang for the buck" is important. I offer this service (Robinson Performance Consulting - powerful, fast street cars) if you want to call me, send me an IM.

Re: Stock engine basics
 

I think one thing I see time & time again on "street" engines is they over cam the thing! I know everyone wants to hear that cam lop BUT one of the best little street engines we ever built had a cam with about the same specs as Edelbrock Performer! (went 12.88 @104 on 87octane in a 67 Camaro)

Re: Stock engine basics
 

I sold my 2nd 69 Camaro to a friend who completely blew the car apart and rebuilt everything. When I had it, it just had a 307 2bbl. with lackluster performance at best. He had a guy build a 427 for it, with a setup that would pull real hard between 3 and 6k. He also had a 4.11 gear and a ST-10 with 2.88 first in it.
Even with MH street tires, it was scary fast (to me at least at the time, 1979).
Man I'd love to have that car back now!

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

Re: Stock engine basics
 

The General Kinetics cam in my '56 Chevy in the early/mid '70s. The lobes were almost square. Killed valve springs in three or four races. It was the 2X4 bl 225 hp Corvette engine, solid lifter deal, valves set at .003"/.003" (stock was .012" - .018"?) hot. Was faster than anything else I tried. Looked flaky but always past Red Anderson's tear downs. Red would check it, look at me and shake his head, but he always passed it.

Re: Stock engine basics
 

Another way of looking at the differences. A factory built performance muscle car from the '60's to 1970, the very best of the best, made 1 HP per cube approximately.
Most of your "bread and butter" muscle engines made around .75 HP per cube.
A modern Stocker version would not even be a serious engine unless it made in excess of 1.25 HP per cube.

And like everybody else has mentioned, it's a package deal. You can't compromise on one area.