Projects =Rebuilding the Plymouth Flathead=

Here is the comparison. On the left, before. The right, after..

 

By the way, I picked up a set of grinding stones from the local 99 cents store, haha. They do the trick when clearing away a lot of material and shaping.


I used this carbide burr from eastwood (80 grit) to clean up the grinding work.

 

The best way to get the porting done All the way around is on an engine stand!


So far I have about 4 hours into today's porting work. Hopefully tomorrow I'll finish. Then to clean up under the cylinder head. Stay tuned!

 

Nice.

Are you going to keep the large section free of paint, as shown in the photos?

If so, what can be done to inhibit it from rusting? Gun blue or a rust converter that blackens the metal?

 

Nice looking bolts. Different.
Interesting color combo, too. Can't wait to see what it'll turn out like!

 

plym49, I realized this after I took all the masking off. When the valve covers and intake/exhaust manifolds are bolted on, there will be some bare spots. I'm going to go over them with a little touch up color and clear.

 

I can see that that is a tough area to paint on these blocks. No rough casting to provide additional tooth, and hot spots around the ports. By the time the manifolds and valve covers are on, all you will see are little slivers of painted area, so I guess no matter what you do it will be OK.

When my motor goes back together, I am going to try to hide as much as possible. No ground cable on the head bolt, for example.

 

I see your point on poor lubrication for the top-end on these motors as far as oil galleries go. But, when the engine's assembled, the cam is almost located at the bottom of the block! Close to the oil pan and almost next to the oil pump! Plus, as the valve tappets are rotating when operating, they continue to lubricate the internals by the valves. I'll have to look into that. Someone correct me if I'm not making any sense. Then we'll see about this 'cross-drilling'

 

Thanks. I want to make it look as clean as I can, and I don't want acorns.

The tan you are using really looks nice. Hopefully mine will look good, too. If not, what the heck, I'll drive a couple of thousand miles and it will be dirty anyway. LOL

 

I read somewhere - it probably was one of the other forums dedicated to these cars - that the lifters got very little lube, basically splash. The lifters at one end of the engine, it might have been the front, supposedly run almost dry, and this was given as a reason for excessive valve guide wear on these exhaust valves.

If this is true, I wonder if it would help to set up a little bypass spritzer similar to that used to lube the crank timing gear. The oil filter return line could plumb into the valve covers, and with some flattening or shaping, could spritz oil to the areas in question. Another way into the area might be to run an internal steel line lengthwise through the lifter galley, getting access from the opening in the rear where the road draft tube mounts.

 

And we're back! Day Two of Porting the Flathead:I Came across some issues, well, concerns when smoothing the chambers
of the intakes and exhausts. Here are some pictures..

Worked in a rotating sequence. Grinding all chambers from one side, then rotating the block to grind and smooth the other side of the ports, etc.

 

I rough ground the ports on all the chambers (in this pic the exhaust is pretty much cleaned) and then will go over with the 80 grit burrs.

 

This is my concern..


The areas around the guides cannot be reached with the burrs I have. Even the most narrowest.


I realize now that I should have done the porting prior to having installed the guides. Unless I find a skinny burr to clean up around the guides and edges. My question to the porting guru's out there..Will I be okay if they stay like this? I mean, as far as breathing for the engine..I know the amount of work I've done until now will help, but I also don't wanna half ass it. So, should I remove the guides and clean it all up??

 

I've also decided to clean up and smooth out the cylinder head's piston bowls. This is too much fun! More tomorrow folks! Thanks for letting me share.

=Adrian=

 

carefull!! I think the best and only thing to the cumbustion area of the head is to bull nose the ramp at the edge valve chamber area. Any more reduces the CR you just gained by milling the head.

 

I see..Thanks, plym46. I'm about done with all the porting on the block, getting as close as I can around the guides and I'll call it good. I'm being extremely careful to only CLEAN the surface and not take much material off. I think I'll be alright with that. Wouldn't want to get in a water jacket Going to smooth the piston bowls on the cylinder head in a bit, too. I'll post some picture later today. Thanks for the tip!

 

You're doing a great job, and I dont want to seem like a party pooper, but I think you should have done a wee bit more research before tearing into the porting.
Current conventional wisdom among those knowledgeable in these engines states that porting is by and large a redundant exercise, and that it actually can be detrimental even. Apparently the smoothing of the ports eliminates a lot of the swirling of the mixture, which is necessary to retain atomisation. Dont bother with relieving, it is not necessary on these blocks as it is with V8s due to valve angles.
The path to power lies in the compression more than any other mod. It's quite safe to run up to 0.90" mill (total cut) and this will net a ratio of up to 8:1 depending on your bore.
Be careful with your cam grind. The beauty of the Mopar is in it's low end torque, and you need to ensure the grind will retain this.
Cross drilling on 1/2 and 5/6 particularly is going to keep her alive at highway revs, but it's not totally straight-forward. I would recommend a PM to Hudsonator, who has done an incredible amount of research and experimentation in this area. He will save you a lot of grief, and I dare say may verify my comments about porting. He will no doubt point you to a link (which I've lost) on an inliner board which runs to something like 70+ pages of discussion about these matters as they pertain to these engines.
Hope this is of use.

 

Thanks for the response, rockabillybassman. I was looking through some old posts and found one on these old flatheads and some performance mods that have helped others on here. Also on another forum dedicated to these engine, P-15, D-24. And read on some threads concerning porting. the information I gathered was: That porting/smoothing the 'rough cast' on these intake and exhaust chambers helps a tad. In theory, a smoother combustion chamber equals increased air flow and greater efficiency. Sure, if there is alot of casting removed the compression gained from milling and decking will be minimized but then there are always compromises. Going .060 over on this engine improved my compression. Decking the cylinder head almost .020 and the block about .020 helped as well. I'm not looking to gain 100hp but just want to improve the reliability and efficiency of this little motor. Eventually, I'd like to swap the tranny for an overdrive and change the rear end out for something like 3:55 gears (that should be ideal and hold up well). The atomization you speak of is when these porting/polishing jobs are overdone. I have a friend who owns a shop and builds race motors all day long-same type of design with the valve chamber layout and they port all the time. Anything over 80 grit or a mirror finish is too much if you ask me. That's when you start to get fuel drops collecting in those chambers. I've heard of some guys that have overdone port and polish jobs so much that fuel makes its way into the cylinders, some atomize and some without atomizing...then they get fuel coming out of the mufflers!
A once-over on these chambers with no finer than an 80 grit should be alright. I guess the only way to truly tell if I've overdone it, this way, would be to put it on a flow bench and run the engine. If anyone has done this and has numbers, I'd like to see what's what.
In the end, I say a once-over on the intakes with 80 grit is ok and if there is a mirror finish on the exhaust ports, also okay as it will help with carbon build up.

 

Today I finished up the porting on the block. I'll rough up the cylinder head a little, soon. Here are some pictures..

Exhaust port close for gasket matching..


Cleaned up all the way around..


more...


All done..




Well, that's all the porting on the block. I just have to do some work on the cylinder head 'bowls' then a little matching when the intake manifold arrives. What do you guys (and gals ) think?? More to come and thanks for letting me share!

=Adrian=

 

Great to see your piece on "the other flattie"!

As far as chasing the threaded holes, what you want to use is a "chase", not a "tap". Chases are specifically for cleaning up existing threads, they won't make the threads any looser. It is much like using a new bolt with slots cut in the threads, but some are made to "restore" out-of-shape threads, rather than cutting them. Here's an example:
http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM%2D900200&N=700+4294925139+4294925137+4294853264+115&autoview=sku

Anxious to see more of your build!

 

Make sure you clean that block VERY good before you start the reassambly, that grinding dust and chips will be everywhere.

 

I don't have anything new or truly constructive to add at this point, only to make a comment-
you mentioned porting and flowbenching one of these engines--

I am in process of collecting the materials to build a flowbench, specifically for this purpose. I fully intend to have a notebook full of flow data for these engines, including stock and aftermarket intakes, stock and aftermarket exhausts, B&B one barrels, etc.

it'll be a while, but that info is coming.

 

Hey everyone. Hope everyone's christmas was swell! Over here, the show must go on and I'm aching to keep working on this motor. It's been busy but I'll post pictures soon. Taking my crank to get grinded, painting all inside valleys with a damp-proof primer/ rust inhibitor, and gonna start mocking up the intake to port match, etc.. Stay tuned!

=Adrian=

 

I'm looking forward to your discoveries, moparsled. It'll be great to actually see what works and what's just redundant. And, hopefully, it'll debunk my theory on the pros of porting these flatheads! Thanks!

 

Some more pictures of progress for the end of this year..
Hope everyone had a swell holiday and has a safe and happy new years!

If I remember correctly, Glyptal has the same ingredients as this:

This here, is a damp-proof primer. Same stuff-but cheaper! For the cost of a quart I got a gallon!

 

Got all the valleys in the lower end..






I'll clean up the bearing journals before assembly but I think I got a pretty decent coat.

 

Then did the valve area..

 

That should do it. I made sure to carefully try and get a good coat behind the openings where the valve covers go and by the entrances of the timing gear.

 

'Twas a great christmas! Here's what I found under the tree



That's right folks! Dual carb setup by Tattersfield! I nearly cried when i saw this baby!

 

With two ways to mount the carburetors I thought this was, not only unique, but a piece of art in itself!



Can't wait to smooth out and polish!




Here, you can see the original blue paint that Tattersfield branded these little intakes with..