improving flow for the 3FE’s top end (5 Viewers)

[FJ40Jim]

Okay, some more photos now that the head's back from being hot-tanked and Magnafluxed. Again, there are more photos and higher res. at the photobucket link in the first post.

General shots of the head casting. Nice and clean, what a difference.

Doc, can you get a close-up up of any/all casting numbers on the top of the head?
The born-on date should be encoded there somewhere.

 

[PabloCruise]

Doc - check your Jim C link - it does not work for me...

It seems the first 4 links are brokeded.

Just found your thread:

https://forum.ih8mud.com/60-series-wagons/143089-3fe-vs-2-3f-carb-cyl-head.html

 

[PabloCruise]

Doc, can you get a close-up up of any/all casting numbers on the top of the head?
The born-on date should be encoded there somewhere.

Can I determine vintage of my 3FE by the number stamped on the block by the starter?

(Hijack over)

 

[FJ40Jim]

Can I determine vintage of my 3FE by the number stamped on the block by the starter?
(Hijack over)

Approximately. But the exact date is cast on the side of the block, and the top of the head.

 

[FJ40Jim]

Is this typical for old valves, or these look particularly rough?

Normal operation.

Now what to do for new ex. valves. Go cheby (I'll have to dig up an old thread where Jim C. suggested good chevy valves to swap), go new Toyota or try to find some decent used. I'll have to check the FSM to see if they come specced to one stem diameter, or several options....

3F stem diameter is 8mm. I have buckets of good used ones for you. But if the valve stems are worn, so are the guides.

Here's a good source for inexpensive, decent stainless SBC valves:
SI Claimer Series Stainless Steel Valves

Chevy valves would be a little cheaper but it would be easier to install Yota instead of having to research.

It's not difficult to put the 1955-1995 SBC valves in the 1951-1964 GMC truck (toyota) head. They use the same valves originally, toyota just metrified some of the dimensions. Height is the same, and the stem diameter & head diameter is slightly larger on the SBC parts, which allows cutting into new metal on the 3F valve seat and guide. It's like getting new seats and new guides for free.

 

[ntsqd]

I wouldn't be too critical of those ports. To me they look pretty good from an appearances point of view. No idea about function.
Oh yeah, the area right behind the valve head is called the "bowl" of the port.

Depending on the hot tank chemical used they can submerge the intake in the hot tank for a day or overnight if they keep it hot. That will help in getting the remainder of the gunk out of the intake. Just know that some chemicals are too aggressive towards aluminum to do this. Others are fine.

 

[matt.mcinnes]

Some of the links in the first post are not working.

Other than that keep up the good work

 

[Moby]

Just getting caught up on this thread... nice work! My 3FE head was ported and treated to nice stainless steel valves as part of my rebuild. Unfortunately I don't have pics to share. The machinist (Portland Engine Rebuilders) that did my rebuild does a lot of performance 2F and 3FE rebuilds and ports the head as part of these packages. When I talked to him about mine he said that he focuses mostly on the pocket in these heads (aka a "pocket port" job) and then does minor clean up in other areas. Said that the pocket work was the most bang for the buck.

Mill the head some to bump compression and add an upgraded camshaft to feed that extra flow capacity and you should be quite happy with the results.

 

[GLTHFJ60]

I'm tuned in! I'm excited to see what improvements you'll be able to make. I might have to buy a spare head and copy you!

 

[RockDoc]

Doc - check your Jim C link - it does not work for me...

Should be back in business, there were 4 that were messed up. Somehow portions of the address were repeated (i.e. /60_series/60_series/60_series or something like that).

 

[RockDoc]

Doc, can you get a close-up up of any/all casting numbers on the top of the head?
The born-on date should be encoded there somewhere.

"8" between #1 and #2

"1" or "I" between #3 and #4

"G" between #5 and #6
"61080____8___1____11" above the ports for #5 and #6

Thanks for the link for the valves, cheaper than I would have guessed.

 

[RockDoc]

Just getting caught up on this thread... nice work! My 3FE head was ported and treated to nice stainless steel valves as part of my rebuild. Unfortunately I don't have pics to share. The machinist (Portland Engine Rebuilders) that did my rebuild does a lot of performance 2F and 3FE rebuilds and ports the head as part of these packages. When I talked to him about mine he said that he focuses mostly on the pocket in these heads (aka a "pocket port" job) and then does minor clean up in other areas. Said that the pocket work was the most bang for the buck.

Mill the head some to bump compression and add an upgraded camshaft to feed that extra flow capacity and you should be quite happy with the results.

The far side of the bowl (opposite the ports) seems to impose into the bowl farther than would be ideal. A function of the head mould and release angles and such I suppose... Anyone have a good way of measuring the thickness of the port/bowl walls? Or do I just get a set of different shaped calipers and hope one will have an arm that will reach through a coolant passage? Would sure be nice to know what thicknesses are there for safely removing metal without breaching

I think most material removal will focus on the bowls to help guide flow around the radius and direct it into the chamber with some swirl and angle w.r.t. to the elongation of the combustion chamber. I'll streamline flow around the valve guide a bit, and clean up the transition between the casting and the valve seat insert. Don't want to open the ports up too much and drop the velocities, just clean-up and smooth the casting surface - slight texture for the intake, polish for the exhaust. The chamber will be polished, and depending on how it tests with the models, I may angle back the wall of the chamber a bit next to the spark plug to allow for more clearance where more flow wants to come out around the intake valve. There are some other tricks from Dalton's book I'll test out too, but I'll explain them when they come up (hints: venturi effect to fight flow separation around the small radius, features to impede reverse flow, valve profile,....).

 

[matt.mcinnes]

From what I understand smaller fast flowing intake runners produce more torque, larger intake runners more HP.

Oh and your valves are good for scrap.

 

[RockDoc]

From what I understand smaller fast flowing intake runners produce more torque, larger intake runners more HP.

That's what I've always heard too, and I'm not interested in improvements much beyond 4000 rpm.

 

[FJ40Jim]

I think the date code is 8 1 11, i.e. 1988 january 11th.

 

[RockDoc]

Damn, must be one of the earliest 3FE heads. Anyone know when production on the 3FE began?

Got some more time in on it this evening. The silicone mould-making process has started. I'm using a product called Mold Max 40. It's a 2-part product that you mix up similar to epoxy, and is supposed to cure in 16 hours. This particular variety has quite a thick consistency, flowing like a very think cake batter.

To save a bit on the amount of silicone used, and to hopefully make removing the mould easier, I used wax covered wire to fill part of the port runner space. I cut and bent coat hanger wire to the general shape of each port runner, then built up wax on it by dipping in melted wax, then cold water, and back and forth, ....... like candle making. After building it up thick enough, wax was removed off the ends so that the bare wire would sit on the valve guide at the valve end, and poke through a hole in the acetate film taped over the port at the other end.

Sticky-tac was used to plug the spark plug holes, partially fill in indentations for the air injection ports, and to hold the valve end of the wire/wax doo-hicky.

A couple pictures of the head prepared for the silicone. Overhead projector transparencies were used to cover the ports. I should have been more careful in cutting them to size and taping them in place, as I did get some minor leaking around them, remedied (somewhat) by wedging pencils in to hold the acetate tighter the the side of the head.

For the first portion of the mould, the head is upside down, with the manifold mating surface sitting lower than the spark plug side. The port runners were filled to approximately the level of the valve guides. Once the silicone sets, I'll remove these moulds (may have to melt the wax to allow more flexibility of the silicone into the resulting void), clean up the valve end and add some indexing depressions, re-insert them, add some release agent (Pam) and make the second portion of the mould (the combustion chamber and valve bowl).

I've decided to make a mould of the CC and intake and exhaust ports for #4 (which will be the main cylinder used to test flow enhancement) and only the CC and intake ports for #6 and #2 (these 2 have the end member geometries for the intake runner approach angle, these will be used to test ways of balancing flow between the 3 geometries).

Hopefully tomorrow night I'll get the second part of the moulds poured, and can post pics of them on Sunday. I guess I should make a 2-part mould of the intake valve while I'm at it, so I can cast epoxy valves to test different possible turned profiles.



Curtis.

 

[overhanger]

Damn, must be one of the earliest 3FE heads. Anyone know when production on the 3FE began?

Damn, some people's kids!
8/87 was the first month of 3FE production as far as I know.

 

[RockDoc]

Never let someone tell you pulling silicone rubber out of a cast iron head is an easy task. It's 7:40 AM here, and I am finally going to bed. But, the second pour of silicone is done, so I should have full moulds to wrestle with on Monday morning.

Good morning all.

 

[iaintscared1969]

You are a die hard! Keep up the great pics and write up. Amazing what a little bit of elbow grease will get ya!

 

[RockDoc]

Some pics from last night. I'll have better photos of the silicon moulds once they are complete.

Moulds of the port runners. The CC/valve bowl portion of the mould will butt up against these, with indexing marks to make sure they can be re-assembled properly once out of the head.

Second part of a mould for the intake valve poured.

Combusion chamber/valve bowl portion of mould poured. The valves poking out are there to block off the opening in the valve guide, and have a build up of wax around the stem to displace some silicone and leave a void in the open portion of the valve bowl/opening (making it easier to remove these pieces I hope).