• To ALL forum users - As of late I have been getting quite a few private messages with questions about build ups here on the forum, or tech questions about your personal project. While I appreciate the interest, sending me a private message about these topics distracts from, and undermines the purpose of having a forum here. During the day I wear many hats as a small business owner-operator and I work tirelessly to provide the absolute best service possible to you, our valued customer. When I created this forum I rounded up some of the best minds I knew so that any tech question you might have could be asked and answered by either myself or one of my highly experienced moderators, this way the next time this same question is asked the answer can be easily found and utilized by the next IH enthusiast having the same question. This allows me the freedom to run the day to day operations of the business and minimize the impact to shipments and shop activities that these distractions can cause. It is of the up most importance for me to complete the daily tasks in order to best take care of you our customer, all the while providing you a forum to get the level advice and input you have come to expect and deserve from the premier IH shop in the country.

    So with that I ask that anyone with a question about one of our build ups or a general tech question to please use the forum as it was intended. I am absolutely available by telephone to answer your questions as well but at times may direct you back to our website to better field your question or questions. Most other private messages I will be glad to answer for you.

    Thank you for your understanding.

    Jeff Ismail

Draft Tube vs. PCV Valve


New member

Looking for opinions on crank ventilation. I am in the process of building up my 800 (152, T18, D20) and believe I have enough parts to do either method of crank ventilation. My restoration is not a "line set" restoration....more of a resto mod as I don't know the year or original equipment for my Scout.

Is there an advantage to the pcv valve vs. the draft tube? Will the vehicle run the same with either set up? Is one more "Scout" true than the other?

Thanks in advance!


According to the factory parts catalog MT-113, the change from draft tube to positive valve occurred during the Scout 80 model run with chassis number FC 63573. So from a "period correct" standpoint, your later 800 model would be well into the PCV style. I don't know all the science or precise vernacular to properly explain the pros and cons of one system versus the other. I just know the general consensus and modus operandi has long concluded that the road draft system made for dirtier conditions both inside and outside of the engine.


Active member
If it were my engine PCV Valve. There is no possibility of dirty air in the crankcase with a PCV and no stinky fumes from the road tube.