Wc or wd head for pulling?

I'm trying to build a pulling motor for my wc and I need you guys professional opinions about which head is better. I've got a wd45 block, wd45 crank, 4 in. High altitude pistons and rods. Which head would work best with my set up? I can do modifying if needed, but which head produces the highest compression and power? Thanks ahead!

It's not going to make any difference.  Weather the spark plug location makes any difference or not isn't really worth thinking about, the rest of the head and these engines isn't verry "performance minded" and your spark plug is the least of your problems.  The short head will save you some weight, both heads will offer the same compression ratio (ok the short head has just a slightly bigger plug pocket) but for all practical purposes it's not an issue.

Takeing a bone stock head, there is little that you can do yourself to improve things without haveing some machine work done first.

Lets just say you are useing your stock valves and just want to improve things all that you can with those valves. The stock seats are verry wide, and they are smaller diameter than the valve can use. Haveing a machine shop trim the valve bowls out and cutting the valve throat areas larger, cutting the seats larger to take full advantage of your valve diameter will help. Getting fresh and clean seat angles is a must. Hopefully your local machine shop will have the ability to cit a 3 angle seat. I've tested some things, just stick with a plain 45* seat angle.

Back cutting the valves really didn't test any better. The thing that helped more was cutting a radius on the face of the valve, by this I mean simply putting your valve in the drill press and takeing a sanding disc and breaking the edge on the face of the valve. As the air comes through the seat area it goes past the valve, where the valve head is there's a void spot and the air curls around the edge to fill it. By cutting a radius on the face of the valve it helps the air flow around the valve with less turbulance. This is something simple you can do with basic tools you likely have.

It doesn't take much trimming in the seat and bowl areas to make an improvement. The port is big enough for the rest of your parts. Trying to do the best you can to work a little radius in the corner where the port makes a T or goes to one cylinder or another will also help slightly, maybe if you have the tools to cut a nice radius.

Shapeing your valve guides in the ports and trimming them back will also help some.

There's a few things that most people can do themselves and spend little money with the machine shop to make an improvement. But I have to say, I've seen to many DIY jobs that they wasted their time and made a mess out of things.


Edited by wi50 - 20 Oct 2013 at 11:36am

I will post this once more about back cuts for the sake of those who have trouble with the search.
   Then we get a valve curtain area formula and wi uses a 45 degree angle . Lets go with the 45 degree single angle wi proposed. If I move that 1.6 valve .100 of valve lift I have 72 thousandths of a inch gap for air to flow all around the valve . A 30 degree angle at .100 vave lift has a measurable gap of 87 thousandths of a inch . By this you can clearly see the advantage of a back cut at low lift . The top cut plays more into mid and full lift values . The correct top cut can easily raise mid lift by 20 cfm and more at full lift. Then there is also convergence and the stem diameter plays into those formulas as well.

Edited by jpankey - 20 Oct 2013 at 12:48pm

One othe thing you can do yourself is to radius the corners off in the intake manifold.  WHere the carb neck transitions into the intake manifold runner is the hang up for the manifold.  The air has to bend a sharp 90 degree corner.  There's only so much air that is going to bend around that corner.

I wonder why it is the MP's of this world can not understand the difference between a basically stock tractor engine running at 1600 rpm and a hopped up one running a 6,000?

CTuckerNWIL wrote: I wonder why it is the MP's of this world can not understand the difference between a basically stock tractor engine running at 1600 rpm and a hopped up one running a 6,000?

oh its the mps that understand 1300 rpm motorload and the need for a little extra at low lift . its the wis that show the two barrels cant grasp but even the twin 97s like mis allis understand the idea of stuffing a cylinder as soon as possible.
as for the heads 4 inch head is better . if it just came down to cooling . A engine with warm oil and cool coolant makes the most donkeys and the head that has the most coolant capacity is ......

Edited by jpankey - 20 Oct 2013 at 6:44pm

Well I can always answer questions with truth and logic. I'll answer pankeys question as to why I didn't send him a cylinder head with the same truth and logic.

A. He's got no way to test it.
B. He's a proven liar and in generally FOS.
C. It's being used..or at least it's bolted to a running engine.
D. All the above.

The answer or answers are easy. I know we've covered this before, it's no surprise we have to change the subject and cover it again.

For those of you new to this, a few years ago I had posted some flow numbers in a thread where someone was asking some questions. I had outlined the process of how it was done and posted some pictures as to how the results were achieved through filling areas of the head, modifying ports, basically makeing new intake ports in a head. To make a long story short our boys in east TN weren't bright enough to grasp such a subject and offered me a couple hundred bucks to send the part down there.

Don't worry, we know how the thread will turn out. We started a thread in which someone asked a few simple questions as to how they can help themselves find a bit more power and the VI is up to his old antics. At least with enough blocked IP adresses he can only be stupid part of the time and not all the time.

It's happens all the time. Someone thinks they can improve on a part or an engine they bought only to end up working hard and going backwards in performance.....oops sorry pank. It's a familular situation for you that's been pointed out in the past. This thread about what a guy can do himself is another example of how what a guy thinks isn't what's always best to do.

Edited by wi50 - 20 Oct 2013 at 9:31pm

You sure it wasn't the schedule 80 all thread factory that burned down. I been looking all over for schedule 80 all thread since pankey introduced us to it and I haven't found any to date.

WF owner wrote: What modifications can be done (to either head) to make it flow better? Is there anything the average Joe can do or does it have to be done by a machinist?

If I had known what a can of worms I was opening, I wouldn't have asked, but thank you for your INTELLIGENT answers Marty! You explain things so even a guy with no engine building experience (like me) can understand, even if I don't dare try it.

I long ago learned to do what I do well and leave the other stuff to the pros. If I ever decide to build an all-out pulling engine, I will be talking to you Marty!!!

according to Ml that motor with the fire rings and all thread studs was whipping up on the natpa kids before they could spell fire ring. I am sure he will be posting pictures of the finished project on yt pulling forum where it can be appreciated by pullers.

Mitch, you are your own worst enemy.

Doug Henderson has been making fire ring head gaskets on big inch MM's, Olivers, Allis' and IH for 20 years. Thats who taught me. You think you are so special because you bought an old Shipman engine. Dude, seriously, thats like cheating off the jock's test answers! You may have seen it done now, but that does not make it the best way. Like your pistons that come out the bottom.. Like STAR WARS said "Who is worse,The fool or the fool who follows the fool?"

Ive been in more builders engines than you ever will. Guys like Shipman, Bos, Kolberg, Barney, Zyrup, Birdsong, Motec, Chuck Lewis, and a few others. Ive helped guys like Doug and Baker do stuff. I get back and fourth with Lawrence Wilson on ideas..Wi50 is a friend, and we've worked on alot of stuff together...What Im getting at is this..There are multiple ways of skinning a cat .Not all of them are correct. I may not have half the understanding guys like LW and Wi have, but, Ill tell you this. For a guy who rehashes someone else's worn out junk, cant show his work, is a proven liar, and does not pull (winning as the only tractor in the class does not count on your daddys Jd) you sure think you are something special.


Edited by THE-MAN - 22 Oct 2013 at 4:27am

Butch, to "pull" in public, wouldn't you want something that could run the whole length of the track 

I would bet goat ropers somewhere are making jokes at Panks expense...