Thought i would share this on this forum also. Been looking into installing a PCV system in the 235 for a while now. I just got around to it last week. Went shopping for some bits after seeing what others use for the downdraft tube hole. Some use metal sleeves to reduce the dia of the hole, others drill into the existing draft tube and mod it. Some use a larger grommet and cut it down to get it to fit. I came across this part at a MOPAC parts store the other day. Its a grommet that fits snugly and perfect in the downdraft hole. Part number is in the picture. The grommet is about 3/4" deep and also has a recessed ring around it that is a good place to install some gasket maker in prior to pushing it into place. PCV is a FRAM FV184 The PCV valve slides in with the aid of a little oil and some force. The full assembly is not going anywhere. The overall price for both parts was about $5 I think. Though I would share for those interested.
Good deal Was stripping my motor a week or two ago, and didnt know what the draft tube was. Some google searching turned up this method and the freeze plug method (among others). I do like the simplicity, and the lack of clutter vs. modifying the draft tube. Thanks for the numbers!
Thanks for posting this. I hadn't considered the upgrade, but Google tells me that not only will it help keep oil off my driveway and the bottom of the truck, but it will also help prevent moisture condensing in the oil. Will add this before I get back on the road. Thanks again.
I'm a little concerned about how close the vacuum point is to the crankcase. Most PCV systems evacuate from either a rocker arm cover or the valley cover of a V8. I have no practical or scientific knowledge that says your solution won't work properly, just worried about oil splash up into the PCV valve. That said, it is a real good looking and simple solution. Let us know how it works.
A couple of considerations... Ok...here goes...even though I have not finished my own system. I had a friend that a couple of years ago gave me a PCV system from a California Caddy in 1954(I think). Back then they used to make a rebuildable PCV. The rubber piece just tightened up in the hole with a bolt/PCV. Got it in and fed it to the intake vacuum. It changed my air fuel mixture and a few other things, I guess. At first, I couldn't get it to idle right. I still have not got it perfect, but it works better. I really have not had time to tinker with it(2 years now), but eventually I will get it perfect. Some of it is based on research and stuff I have found out since that time. Some of the things to consider: Fram FV184...what is that for? I believe that those are not all created equal...V8 pulls lots more than a 235 or different engines are tuned to certain PVCs...they are not all equal. One of my problems is that I think the system I put in is from a V8, so is not really tuned perfectly for my 235. There is a way to adjust the tension on it, but I need time...it apparently takes different tensions at different times. The spring tension and how much is let by at idle or under power or at cruise. It might need to be a little higher above that hole, so splash does not plug or effect the PCV. Which means it might need cleaning out more often under different conditions. I had heard that it actually would be much better to run it in line instead of at the hole. That way it avoids drip back...thus plugging it. Remember, that engine needs to breath...it needs too. If not it could be building up pressure inside, so that you'll have a gusher of oil leaking all over the place...putting pressure on all the seals. I don't think that it is a simple solution, but with keeping experimenting going eventually it will be right. I have not had time to be doing the experimenting, but I did have to put a hose clamp on the hose going up to the intake an lock it down about half way. This question has reminded me to check that system....clean out the PCV and check to see that it is sucking, but not too much. Oh, let us know how that system works. It sounds like a super neat, simple system. Did it change tuning/carb setting much? I want to try it. Oh, I am working on another engine...I could add it there. Good Idea! Either way...it is supposed to be much better running a PCV system than the draft tube, but don't get ride of it, yet, It is the original and better than nothing. Rod
Hey Bill, I did the same to my truck today. There's a baffle right in front of the opening where the PCV valve plugs in, so I'm hoping there won't be a splash problem. The truck idles exactly the same, as far as I can tell. Didn't test drive, as we had 3.8 inches of rain, and I just polished the truck today as well. BTW, I've registered my truck in the Halloween car show on OCT. 25 down near Airtex and I 45. http://www.visithoustontexas.com/includes/events/7th-Annual-Halloween-Car-Show/25268/
I just saw the Dr. He said come back in six months. Still have a little swelling, and some pain when I'm still for a few hours. I'm able to do pretty much anything I want to though.
No butt-kicking contests yet though, huh? Let me know if I need to attend the car show and stuff the ballot box for your GMChev.
The PCV number i got was from another few guys online that have done a PCV mod. One guy drilled a hole in the top of the draft tube, another put holes in the side of the tube and some followers did the hacked frost plug and grommet option. I did not see any complaining about the lower option plugging up or sucking oil yet. Lots mentioned their concerns about it. I always wondered if the hole in the tube was very effective as going directly into the hole somehow without the draft tube leg. I know the original Chevrolet option was on the draft tube that kept the leg and had the PCV out the side. Would you not possibly be sucking some air back up thru the tube when not moving fast or when stationary? Think about it.......long tube...no restriction....would not some of the air your removing at idle just be fresh air and not all from the crank?
Bring it on Bill H.! (the car show, not the butt kickin') I could enter a butt kickin' contest, but wouldn't expect to advance very far! ;o) I could probably use some ballot box stuffing, though. Mainly just want to go to the show and see what's there. Morabuffalo, I checked the applications for the pcv valve I used on my truck, and it's for everything from a 262 to a 409. That includes 6 and 8 cylinders. I suspect that it's not an issue after all. Drove my truck a few miles yesterday, and no noticeable change in engine performance. Side note: I've been having an oil leak that I thus far haven't located. I added some UV die to my oil, and cleaned up the underside of the truck, and now that I've installed a pcv valve, I may have solved the oil leak problem. I'll need to make a longer run to be sure, though. So far, I've not seen any die showing up... Will keep you all informed.
For those who prefer AC Delco over Fram, the cross reference to FV184 is CV774C (fits a '75 Blazer with a 350 and 4bbl). This seems to be a popular choice for adding PCV to cars that didn't come with it. Another one mentioned is CV789C, usually touted for more "radical engines" (READ: great big V8s with large cams).
