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Then there is Valve Overlap

By rexrich2k ·
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Cheap Tricks..

by rexrich2k In reply to Then there is Valve Overl ...

When I was an engine builder I had lots of extra parts to mess with so I was able to experiment around a bit.

A few ways to get a lot better power and not spend much more..

Carbureted engine; I cut piece of micro wire 1/8in screen to fit under the carb and between the manifold. Doing this would mix the fuel & air far better and made a huge difference in Torque, specially in the 700 to 2000 rpm range. I thought it would most likely kill high rpm performance but it seemed to have no negative effect at all.

The best poor man Torque and HP maker is of course milling the head and deck. Getting the most out of Pump Gas I found that 10.5 ~ 11.5/1 was the best ratio depending on the engine.

Then one other thing most people get wrong.. More Oxygen makes more power.. In most cases using the lowest Octane fuel you can get without pre-detonation (85 Octane) would get much better Torque and crisper HP. To aid in this I would polish out any potential hot spots in the combustion chamber, e.g., all edges, around the spark plugs and exhaust valves.

Spend a little money; Balancing the engine and porting & manifold port matching the runners. A mild Cam can help a lot too.

So doing these cheap things can really make your car engine a lot more fun. I did these things and still pass smog in Cal.

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That is called Blueprinting

by HAL 9000 Moderator In reply to Cheap Tricks..

Where you remove the Production Tolerances and return the engine to what the designer envisaged.

It will of course always make more power as you start with the Ideal and then the shop floor introduces Tolerances which kill of power. They then decide what they can get away with and have an acceptable level of Power and build accordingly.

The one big way to improve combustion is to Introduce Oxygen into the Induction system as it drastically improves combustion and hence power but if you don't have a motor designed for Nitrous Induction it's going to kill the thing quite quickly, or at least drastically shorten it's life. Here I do mean oxygen as apposed to Atmosphere gas which has a much lower % of oxygen.

With Force Feeding engines you push more of a charge into the chamber so you have more fuel air mix to burn and as it is at a Positive Pressure rather than a negative pressure you get more power simply because there is more to burn per power stroke. Again you need the motor designed for this with lower compression that would otherwise be used as you now have a higher pressure inside the chamber and considerably higher combustion pressures involved.

Though with any production engine scraping more power out of it and still using it as a daily driver is self defeating they tend not to mix all that well.


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by rexrich2k In reply to That is called Blueprinti ...

"production engine scraping more power"

For the daily driver in most cases it will not hurt the engine to do some of the things I mentioned in my last post. Just don't let it Ping and keep up on maintenance. I had only 2 problems when doing these mods..
1. I would break the rear Axels a lot.
2. The high compression and low octane was hard on the Starting system. So I went through Starters fast. Then when I solved that problem.. The Battery blew up. ahaha! But MAN once I fixed those things the engine couldn't wait to start!! I could just touch the ignition and the engine would fired up! All the starter had to do was engage and that was it. very fun

Using Nitrous is ok but risky, its too easy to just add a little more ~ and a little more ~ and finally ~ Boom!

For the Street Car and this is why I like to separate HP from Torque, you don't really need more HP. For the most part you get more speed but that can lead to Tickets and Speeding crashes, not good!

But more Torque on the other hand gives you that feeling of big power and in most cases you are going to be showing off Light to Light, more Torque can make you the winner of that race without having to do too much speeding.

I've have had a few cars that would just Lurch Hard to the speed limit in a second and that's a blast in its self. So I've found that Chic's dig Big Torque more than HP, and that's a good reason too ;p

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All show and no go

by aidemzo_adanac In reply to Yep..

HP means nothing in the engine, it's the BHP to rear wheels that matters, which is also a result of torque.

A lot of people buy cars based on HP though, we call such morons the hoods up gang. They are always parked in a Canadian Tire parking lot with the hood up as they pour can after can of the latest super goo into their engines

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Thats it! lol

by rexrich2k In reply to All show and no go

The WD40 and Duck Tape dudes!
"Hoods up gang" lol

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It's a cheesy selling feature

by aidemzo_adanac In reply to That is called Blueprinti ...

It was initially a way to make European engines more appealing in the days when big blocks were storming America. People looking at the 351's 400's etc found that a little 4 cylinder was more aggressive (especially tonewise) with a turbo charger, plus engines were horribly inefficient then, well they still are but were even worse.

These days, it's a cool rally driver feeling, along with those disgusting, tuned exhaust tips you can buy for $50.

There are higher end sports cars where turbo is a definite benefit but for the most part, it's just a way of making a small engine sell for more in certain models.

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Well put!

by rexrich2k In reply to It's a cheesy selling fea ...

Today is a sad reality when you lived the big block days. Now days if you have the big money it takes you can engineer a spectacular engine as opposed to the 60s tech though.

A good example for this is the Top Fuel engine; Being relatively the same size, the early 70s TF engine would be lucky to produce 2000 HP but now 8000+

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So you're saying those tanks of liquid oxygen and nitro-methane

by robo_dev In reply to Then there is Valve Overl ...

that I am fitting to my engine may actually do harm? :) :)

When I was stupid and young, one of my fellow stupid and young friends rigged up a large tank of nitrous oxide to his mother's 1976 Plymouth Volare wagon.

He had no nozzle or even valve, so he simply ran this piece of rubber hose into the air intake and had the tank in the front seat. He simultaneously floored the throttle then opened the valve on the tank while driving and dumped about ten lbs of NOX into the air intake all at once.

The engine stalled on the first try, but after several attempts, it did seem like a small amount of extra power was there. The next week the car blew a head gasket, which may or may not have been the result of my friend's experimentation.

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I've always been tempted to try and use the heating vents

by Slayer_ In reply to So you're saying those ta ...

Just re-aim them into the air box.
So want more power, turn up the fan.
Want cold air intake, turn on the A/C.
Etc. lol

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Pop the hood

by aidemzo_adanac In reply to I've always been tempted ...

Pop the hood and vent the snorkel BEFORE your MAF. Unfortunately modern cars have too many limitations, even if you juice them they computer accommodates the change and adjusts AFM accordingly to manage emissions and slow you down.

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