I routed my road draft tube to my downpipe!

I bought my truck w/ 208k on it...

I freaked out the first time I took it for a road trip and it coated the underside and backside of the truck w/ oil mist...

it wasn't so bad if I went to the coin-op and hosed it off every now and then... but lately I've been neglecting it, and another 35k miles of hard driving means a little more blowby I'm sure... and all that oil vapor collects and coats everything, and I end up with drips here and there, and it's just annoying...

finally got fed up w/ it, and went and got some good 3/4" hose at the hose/fastener shop. looks like the hose you see on fuel pumps at the station.

routed it down across the bellhousing and bent a piece of 3/4" round tube, blew a hole in the downpipe, stuck the tube in the pipe at a 45* angle, 45'd the end of the tube inside the downpipe and connected everything up.

used almost a full bottle of Simple Green cleaning up underneath the truck (STILL a fair amount of grease here and there! LOL!)

I've put a couple hundred miles on it at 70-80mph...

ZERO drips under the truck (even driving around town, the road draft tube would put down a drop or two often times)

ZERO oil residue on the tailgate.

obviously it would be ideal to have a motor that didn't have this much blowby, but it's still within cummins spec, and I would imagine that even tight engines would benefit from a pan evac setup... creating a vacuum in the crank case frees up power and promotes better ring seal.

wish i'd done this the day I got it!

Forrest

 

Got any pictures? I'd like to stop all of my leaks too. I have an old Gatoraid bottle loosly attached to it now - still leaks out!

 

no pics... kinda hard to take pics up under there... but I HIGHLY recomend doing it/having it done!!!! just be sure to route the hose so that it's got a constant downhill slope and there aren't any kinks in it.

if you're anywhere near Dallas, I could do the work for you.

I feel like a kid at christmas every time I walk out and the tailgate is shiney bright white!

Forrest

 

Sounds like a good idea.

 

How many miles on your truck Forrest??

 

Forrest I'm thinking to do this mod too. My truck has spackled the rear with oil drops although it seems not too much collects underneath for whatever reason. I'm not fond of oil drips on the driveway, especially on nice ones that are someone else's.

I did do a blowby test at 351,000 which came out dead on with "new" engine specs but my truck goes through phases where it spackles the tailgate and uses oil. But for some reason it quit doing that recently and oil consumption went way down.

Vaughn

 

my truck "only" has 244k miles on it... my old 1st gen didn't do this with 275k on it... but this truck has had a lot more power run through it, and I'm wondering if one of the two previous owners idled it a lot or something...

makes KILLER oil pressure, runs like stink, but seems to have a fair amount of blowby... when the motor was at operating temp, you could look under there, and see vapor just pouring out of the road draft tube... no pulses, so no bad holes, just more blowby than others...

sometimes better than others... higher road speed = more crud under the truck and on the tailgate... higher oil level = more crud...

drips in my driveway is bad enough, but there have been some pretty bad spills out there, so not THAT bad, but it's downright embarassing when it leaves a few drops on a nice new driveway!

man, if I had back all the money I spent at coin-op car washes, I'd be a lot closer to buying the clutch I want!!

I just got some 3/4" round steel tubing at Home Depot, put it in a vise, heated it w/ a torch, and put about a 75* bend in it... it enters the side of the downpipe and points up towards the top right bolt where the tranny meets the bell... that's where the rubber hose ended up coming down, so I just made the hard tube point to it... wanted to keep everything nice, smooth, and downhill...

Forrest

 

You aren't worried about exhaust gases going in to your crankcase?

 

nope... the way the tube is inserted into the downpipe, it pulls on the vapor coming out of the tube... actually creates a vacuum in the crank case.

Forrest

 

If the back flow of exhaust is a problem, on late 70's Chryslers they had an air asipirator?? valve, If I remember, it was a check valve in a line that went to the exhaust and intake manifold. on a negative pressure pluse in the exhaust it would pull air from the intake into the exhaust, kinda like the precedor to the smog pumps. A buddy on mine used that same valve on a set of headers on his 340 Duster.

 

Didn't some guy suck a bunch of oil out of the engine because the way he had the end of the tube cut created suction? I SWEAR I remember this...

Mine has a fair amount of blowby, similar to Forrest's truck, but it does run great.. I'm very interested to hear what becomes of this mod...

 

Mr Gasket makes a crankcase evacuation system that goes into the exhaust, which several people have used in the past. I tried to create a link here for these at the Summit web site, but couldn't get the link to work.

 

Forrest,

Do you have any pics of thisinstallation? I have the same prob but am leary of sucking all my oil out of the engine. Just want to make sure I do this the right way.

Thanks in adavnce, Zack

 

Dee Rawson vented his draft tube into the DP. He has pictures under drawson on TDR.

Bart,

Did you get a chance to see Dee's truck on the dyno @ Edge?


Justin

 

I know quite a few people who have done this, all have used a check (one way) valve at the the exhaust end to prevent back pressure. I would too.