2" - 2.25 Exhaust Question /6

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Jim 270

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Have a question and i do believe i've read somewhere that moving to a 2.25 from a 2" exhaust from the manifold to back end will help reduce engine blowback. The reason for this ask i i've recently had my PCV valve fail and noticed that i had some oil blow up threw the top pan breather cap and possibly top pan gasket itself.

Another question same topic my breather cap is the one with no spigot for a hose it vents out to the top pan. I noticed on later models (mine is a 68) that the breather cap is also hosed back to the air filter. Is there a benefit to have this done to mine? Purpose for this is i'm looking for way to lessen the leakage and i believe there is fuel component benefit there somewhere to. Thanks in advance any thoughts on this greatly appreciated. Jim
 
The breather to air filtersituation was made for smog emissions, also how many miles or on the engine? Might be some blow by?, 2.25 all the way to the rear is the best set up for a slant six.
 
The breather to air filtersituation was made for smog emissions, also how many miles or on the engine? Might be some blow by?, 2.25 all the way to the rear is the best set up for a slant six.
Thanks on clarifying the breather to air filtration. Blow by what i meant was while driving i noticed smoke not blue oily smoke more whitish coming from the rear of the car I pulled over when i could and then noticed a ruff idle as well thinking i may have had a water leak i popped the hood no water leak little more oil than usual on top pan rim not a lot but a little. restarted car sluggish start to ruff idle limped home did some research quickest cheapest was check the PCV it was making the clicking noise but would sometimes stick i cleaned it with a squirt or two of break cleaner took it for a ride fired right up ran smooth no smoke at all ( i will replace the PCV ). thats when i read the 2.25 exhaust was a benefit. 91XXXmiles just looking for ways to minimize this from causing me extra money down the road. and thanks for your reply:thumbsup:
 
Deuce & a quarter exhaust for the deuce & a quarter motor!
 
Engine blowby is a result of a loss of seal with the rings, nothing to do with exhaust. If that were the case, they would have had the problem new. They did not. Not saying the larger exhaust might not help with power and mileage.
 
White smoke? Check under your breather cap if it looks like chocolate you got water in your block, white smoke is from head gasket leak for coolant burning in the combustion chamber.
 
Engine blowby is a result of a loss of seal with the rings, nothing to do with exhaust. If that were the case, they would have had the problem new. They did not. Not saying the larger exhaust might not help with power and mileage.
Thanks understood. but to be clear are you saying a stuck PCV valve would't cause the smoke and i should be looking at the ring ware. and thanks for replying i'm learning as i move along.
 
White smoke? Check under your breather cap if it looks like chocolate you got water in your block, white smoke is from head gasket leak for coolant burning in the combustion chamber.
Well it might have been PURPLE HAZE i couldn't really tell as i was on the HWY and none when i stopped just ruff idle. No under breather cap was just plain ole oil no gunk. Checked the rad and no difference with the water level either. I seem to have read somewhere that when ring gaps line up you can get blowy to.
 
Thanks understood. but to be clear are you saying a stuck PCV valve would't cause the smoke and i should be looking at the ring ware. and thanks for replying i'm learning as i move along.

No, I never mentioned the PCV valve. If the PCV valve is stopped up or broken, that could cause oil vapor to escape from the crankcase breather.
 
No, I never mentioned the PCV valve. If the PCV valve is stopped up or broken, that could cause oil vapor to escape from the crankcase breather.
Crank case breather?? would that be the breather cap if not please tell were that is.
 
Nice One I wonder if that was intentional for a reference??
Yes, it's just like calling the Buick deuce & a quarter a deuce & a quarter! Or the old Army trucks were called that same being 2 & a quarter ton trucks.:thumbsup:
 
Yes, it's just like calling the Buick deuce & a quarter a deuce & a quarter! Or the old Army trucks were called that same being 2 & a quarter ton trucks.:thumbsup:
I remember my father referring to the military trucks using those terms served with the Canada with you folks in Greenland Thule Air Force Base.
 
Pull the breather out and swipe your finger around in the valve cover, or flip the breather over, and look for white slime or water droplets. This could be normal where you live, and may be caused by short trips and or insufficient running time to evaporate the moisture that your PCV is constantly pulling in from the atmosphere. A too cold thermostat could also do it, as can an open-type non-heated air filter housing. That moisture may be piling up in your crankcase as water, in the bottom of the pan. You need to check it. Pull the dipstick; if it too has the slime on it, then change your oil, or at the very least drain some out, looking for water. You have to do this after the engine has cooled off to allow the water to come back out of solution and settle in the lowest part of the pan. This used to be a common problem in older cars without heated air intakes and non Closed Crankcase Ventilation Systems. You have to cure this, if I'm right, because the moisture will combine with blow-by elements to form acids which don't do your engine any good.
Short trips at this time of year are killer acid producers
 
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Pull the breather out and swipe your finger around in the valve cover, or flip the breather over, and look for white slime or water droplets. This could be normal where you live, and may be caused by short trips and or insufficient running time to evaporate the moisture that your PCV is constantly pulling in from the atmosphere. A too cold thermostat could also do it, as can an open-type non-heated air filter housing. That moisture may be piling up in your crankcase as water, in the bottom of the pan. You need to check it. Pull the dipstick; if it too has the slime on it, then change your oil, or at the very least drain some out, looking for water. You have to do this after the engine has cooled off to allow the water to come back out of solution and settle in the lowest part of the pan. This used to be a common problem in older cars without heated air intakes and non Closed Crankcase Ventilation Systems. You have to cure this, if I'm right, because the moisture will combine with blow-by elements to form acids which don't do your engine any good.
Short trips at this time of year are killer acid producers
Thanks AJ i'm pretty sure the oil is water free as i did paid particular attention to it when this happened and never noticed anything like you described. I do change my oil every season or at 5000kms intervals depending on the travel that i do. The thermostat i will check. I do keep the car in heated garage in winter months. but as you said you could ring the air out here and draw water.
 
If it has been taken proper care of, 91,*** miles is not a lot. Once you verify the PCV and crankcase breather system are both functioning properly, if you still think there is a blowby issue, you can try this product. Engine Restore.

https://www.oreillyauto.com/detail/...1967/plymouth/valiant?pos=2&manufacturer=true

I have personal experience with it. I have used it several times and it does everything that it claims. It comes in 4, 6 and 8 cylinder sizes. Only drawback, if you can call it that is, you must add it again with each oil change.
 
If it has been taken proper care of, 91,*** miles is not a lot. Once you verify the PCV and crankcase breather system are both functioning properly, if you still think there is a blowby issue, you can try this product. Engine Restore.

https://www.oreillyauto.com/detail/...1967/plymouth/valiant?pos=2&manufacturer=true

I have personal experience with it. I have used it several times and it does everything that it claims. It comes in 4, 6 and 8 cylinder sizes. Only drawback, if you can call it that is, you must add it again with each oil change.
Thanks will give it a try if needed. And yes i would like to see the brake rebuild on your Valiant.
 
Blue smoke is oil, white smoke is water. In Canada, during the winter, some white smoke from the exhaust should be considered normal. This is water condensation in the exhaust system. It will take a while to heat up the exhaust system to evaporate the water. The same with the oil. Some white/yellowish slime on the filler cap, breather and dip stick is normal. This is water condensation. It will take a while to heat the oil up and evaporate the water. Short trips, where the engine doesn't warm up is the prime culprit.
 
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