Thread: 4 bbl intakes for EGR system

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I remember now reading in hotrod or another magazine that one way reduce the octane requirement of a higher compression motor is to add a EGR valve,I have a 66 390 and a 65 352 that both have around 10 to 1 compression and I would like to try adding a EGR valve before changing heads. Did ford make a 4 bbl intake or did or still do the aftermarket make 4 bbl intakes for EGR equipped FE motors,could a older intake be drilled so that a EGR carb spacer be used?,changing a intake is a lot easier then changing the heads. Jeff

Originally posted by junkyardjeff
I remember now reading in hotrod or another magazine that one way reduce the octane requirement of a higher compression motor is to add a EGR valve,I have a 66 390 and a 65 352 that both have around 10 to 1 compression and I would like to try adding a EGR valve before changing heads. Did ford make a 4 bbl intake or did or still do the aftermarket make 4 bbl intakes for EGR equipped FE motors,could a older intake be drilled so that a EGR carb spacer be used?,changing a intake is a lot easier then changing the heads. Jeff

i wonted to post on this so i will see the answer to this?. i cant see how a egr valve could chang the octane reqirements of the motor, and its more to a egr system than just bolting it on, but i learn something new every day, so mabey it can.

A short chemistry lesson is in order here. It was discovered way back when, that high combustion chamber peak temperatures (the really short duration high temperatures near the end of the combustion process) caused oxygen and nitrogen to combine chemically and form these oxides of nitrogen mentioned above. Most of the anti-pollution devices of the day did a pretty good job of reducing the other bad by-products of combustion, namely excessive hydrocarbons and carbon monoxide, however they tended to induce the formation of oxides of nitrogen. Something had to be done else we would all die of smog diseases.

The automotive engineers figured that they needed to do something to lower the peak combustion temperatures which only occurred under certain high load driving conditions. They figured they could do so at the expense of power and fuel economy but what the heck, ya can't have everything! If they could only add something to the combustion chamber that would act like sort of a fire extinguisher to cool the combustion temperatures that would do it.

So they invented a way to allow some very inert gas to get back into the combustion chamber only when needed. They needed a source of this gas - it wasn't air, cuz that contains oxygen and nitrogen which caused the problem in the first place. So they chose carbon dioxide. Where to get a supply of carbon dioxide . . . ??? Hmmmm, how about the exhaust system? That is mainly carbon dioxide and water (plus a zillion other noxious chemicals) Suppose we allow some of the exhaust gas to get back into the intake manifold under strict control and only when we need it? That would cool the combustion chamber and prevent the formation of the NoX. Maybe we should call it recirculated exhaust gas (REG??). But a guy named Reginald voted no cuz he didn't want his name associated with a car part, so they called it exhaust gas recirculation (EGR) since there was nobody around with that name.

ok viking ill take your word for that, but will putting a rgr valve on his motor change the octane reqment. enough so he can run 10 to 1 pistons on pump gas?

I run the bucket at (9.5 to 1 comp) on pump gas (93) without any trouble, guess he could try, but personally I always thought it counter productive to introduce anything other than air (or nos) to the combustion chamber, I use a toluene mixture in the cobra (11.25 to 1 comp) at a 20% mixtue to end up with 96.4 octane, works great.

Originally posted by viking
I run the bucket at (9.5 to 1 comp) on pump gas (93) without any trouble, guess he could try, but personally I always thought it counter productive to introduce anything other than air (or nos) to the combustion chamber, I use a toluene mixture in the cobra (11.25 to 1 comp) at a 20% mixtue to end up with 96.4 octane, works great.

i cant see it working