Which of Tim's pistons are those?

And, by the way, I somehow missed the cutaway drawing on the head. Good work.

 

Gary,

The pistons are the KB2347, they should yield 9.3:1 with a stock head. I have had 0.005" milled off the heads, and will have the block decked just to square things up. I'm not sure how clean the combustion chambers need to be. I took out any sharp edges and sanded down the rough cast surface, but am wondering if I need to polish them. Any input about that?

Thankfully I found a 351M/400 head someone cutaway and then I made a drawing from that. I have no ability to cut up a cylinder head myself.

 

I cut up a 351W head to see how to port them. Worked great for me and a buddy of mine borrowed the pieces yesterday to do his. I had mine tested on a flow bench and I made significant gains on the exhaust, but none on the intake side.

As for polishing the combustion chambers, I wouldn't if you are satisfied with the 9.3 CR - which is pretty high in my estimation. But, I've only built one of these engines, an M, and don't know the limits on them. Anyway, in my experience polishing the combustion chambers isn't worthwhile if you've taken the sharp edges off. The rough casting won't have hot spots that cause detonation, and you will lower your CR if you take much material off. I thought I was going to do that on the Windsor heads I ported until I realized that all the heads I had to-hand had combustion chambers at the large end of the quoted range. So, if you want the 9.3:1 you might want to check the volume on your heads.

But, if you are having the block decked you might want to wait until you get that done before deciding on what to do on the heads. I say that because most builders assume the pistons will be something like .020" down in the hole when calculating compression ratio. So, if your machinist removes half of that to square the block up your CR just went up and you may need to take some material out of the heads to get it where you want it.

 

forget who builds timing chain but! www.mpgheads.com scott sells this timing chain with a torrington roller behind gear. frees up friction a little and every little bit matters. Believe howards sells also. really like this upgrade. Anything to free up friction in any engine is a good thing. its a torrington roller behind cam gear. Tim meyer probably sells also. definetly check into tim meyer cam bearing upgrades. scary simple and helps control oil psi to crank, good thing!

 

.. Sounds like you are on the right track with the Meyer/KB hyper pistons... they have a higher compression height (than the stock ones and usual horrible 'rebuilder' pistons) which aids quench effect and increases compression ratio, while lessening the chance of detonation...

.. The stock 2V valves are plenty big for your plans... good to 450-500HP... bigger than the famed Chevy 'fuely valves', even... although replacing stock breakage-prone welded 2-piece valves with even budget aftermarket 1-piece stainless steel (S.S.) valves is a good safety idea for the engine when increasing power and RPMs... check with Kaufman Ford Racing for a good price...

.. From looking at the left green area in your sketch, you may have gone a bit high on the porting in that spot... trying to keep the upper surface of the port more in line with your yellow line helps speed airflow and lessen flow-restricting turbulence... the flow plates that are sold for 4V Cleveland heads also try to fill in large enlargements in spots in those ports that slow airflow in that spot and induce turbulence... slowing and speeding up airflow in spots also sucks the flow energy from the airflow...

. looks like you need a cam around 204/214 duration (@ .050" lift) that favors mid-RPM torque... but still allows more RPMs, torque, HP than the wimpy stock cam...

. Timing chain looks typical for those miles...

 

I received my Ferrea valves yesterday and I think I'm ready to take the heads and valves in for a 3 angle valve job. Here's the before and after pictures of intake and exhaust.


In the before picture, I had already started to trim width off the valve guide boss. Ground down any rough seams and removed the nickle size protrusion on the roof of the port. I also did a gasket match on these, but did not lower the port floor at all.



Removed the bump for the "thermactor pump" or whatever it's called. also I also removed all the flat surfaces around the valve guide. I thought about a gasket match, but the ports are not going to line up with my headers, so they will just dump into the headers as I have cleaned them up.

I did quite a bit of bowl work on both intake and exhaust, some pretty good size seams there. I also cleaned up just beneath the valve seats, not much work required there. The combustion chambers were cleaned up by ginding away anything that might be a source for detonation.

 

I would like to see your pics, but they just come through as question marks.

 

. I wouldn't worry about putting a Torrington needle bearing behind cam gear unless you have a roller cam... flat tappet cams float in their proper place and aren't really rubbing hard enough against the oiled plain bearing surfaces to make any friction...

. I was able to view the pictures by right clicking on them, opening them in a new window, and then deleting the half of the URL that comes before the second 'http', then hit <enter> button...

. The porting looks good... Yes, I also wouldn't bother polishing the combustion chamber more than what a die grinder leaves after a quick cursory pass... just remove any razor sharp edges that could glow red...

. If they need it, you might try backcutting the valve heads bottoms on a fine grinding wheel... that especially helps low-lift flow...

. I'd suggest mocking up a rod/piston/crank/crank bearings/rod bearing on short block and seeing what your deck to piston distance (if any) is before cutting anything off the block deck... the special T.Meyer/KB pistons have a higher (and more desirable) compression height than any other 400 pistons (except big dollar custom pistons, of course)...

. Gary, I also ported a set of 351W heads a while back for a 351W boat engine... ported them out till I struck water... LOL! . Had to weld that spot back up... got a good boost in power, but still not quite what I wanted for that application, even with 10.5:1 KB flat top 2-eyebrow pistons and Crane cam... those 351W heads with 1.84"/1.44" valves, 70cc chambers, and small ports just weren't a good enough starting point for what I had in mind... got another good jump in power switching to World/Dart Windsor Senior iron heads w/ 64cc chambers, much bigger 2.02"/1.6" 'fuely' valves, plus more of my porting/cleanup, radiusing valves and seats, backcutting valves, intake and head gasket matching, etc... giving about 425+HP/425+ lb./ft. torque by about 5750 RPMs...

. Now looking at converting 351M to 408" with about 500+HP/500+ torque...

 

Buzz - I also ported some smog 351W heads, as shown in this album, including flow bench test results. Basically, I actually hurt the intake a bit at .300" lift, but made significant gains on the exhaust by grinding out the thermactor bump and blending, gasket-matching, etc.

So, while I don't know that my experience on 351W heads maps directly to 351M/400 heads, I would guess that there is some degree of relationship. Given that, I would suggest going lightly on the intake as it is easy to cause a problem and difficult to make significant gains. However, the exhaust is easily improved and is where I would suggest placing your efforts.

 

I have a question for anyone that might be looking at the exhaust side...

...nevermind!!! I was mistaken, the narrowing of the exhaust port is strictly to miss the HEAD BOLT! Sometimes it just doesn't pay to be looking at something at 11:30PM. And it is on the side that will benefit from doing a gasket match, so I will be doing a little more work after all!

BuzzLOL - a 408 with 500/500 would be flat out awesome. I think you could do it with closed chamber 4V heads and Cleveland pistons, etc. A lot of work to get from the 350-400 HP range to 500.

 

You said earlier that your headers won't match so you aren't going to gasket match, which I think is fine - as long as the headers aren't presenting a step, an abrupt impediment, to the flow. It is better for the flow to be able to expand into a larger area than to be constricted into a smaller one. Smooth is best, but expansion is better than restriction.

As for the narrowing, that's as you look into the port. But the flow goes the other way, so if that is a gentle enlargement of the passage it isn't a problem - especially if it is encouraging the gas to start moving in a direction to make an upcoming turn. (I don't have the heads nor headers so don't know which way it is needing to turn.). So, it may not be a problem. On the other hand, if it is a restriction or a necking down of the passage then it could be enlarged.

Having said all that, you should compare the ports on your heads with those for a 351W. MUCH larger. So getting the passages cleaned up and straightened out is good, but not nearly as imperative as for those poor souls whose M is upside down.

 

. As Gary mentions, if the headers are making an inward step in some spots for the exhaust flow to hit, creating flow-blocking inward turbulence and a glowing redhot spot, I'd attempt to port/reshape the opening of the header tube to remove it...

. Bends/bulges in the intake ports are usually to clear pushrods or bolts going through the heads... sometimes there is enough meat there to remove some of it to keep the port width nearly the same all the way to the valve bowl area... or enlarge the straight side in that spot to curve similar to the curved side... to keep flow fast and at a uniform speed...

. I want to try for 500HP/500torque with the 2-bbl open chamber heads on a 351M re-modified to 408"... maybe with the later ones, but will keep an eye out for the earlier ones with better ports to start with... open chamber heads tend to outflow closed chamber heads if you have comparable or higher compression ratio... so will also attempt to use mini-domed 351C pistons for higher compression ratio... also try for good quench effects... good flow and high compression will allow reaching my goal with a milder cam so I don't lose torque or MPG... basically, I want a F400 that equals or exceeds the performance, power and MPG-wise, of the new Dodge hemi trucks... while the engine still looks like a slug 351M/400 in an old Ford pickup...

 

I have a similar goal, 500 ft lbs, but the HP looks to be more like 400. And, I'm taking a very different approach: Edelbrock heads with Tim's pistons giving ~9.5:1, with a roller Comp cam, Edelbrock intake, and Edelbrock carb, all dumping into small-tube headers. Comp's CamQuest dyno software says I'll get the above #'s at 2500 RPM, which is where I want it. Yes, I could get closer to 500/500 but I would have to use a larger cam and wind the engine up, which I don't want to do.

 

Gary,

Yep the 260 clear up to 351W used the same basic head (save the BOSS 302 of course). It killed me to see the Mustang use those things, when there were so many better flowing designs. Oh well! The new 5.0 seems to do pretty well with four valves!

BuzzLOL,

I'de love to see that build! I've toyed with the idea of having this engine dynoed. I may do it, we'll see.

 

. For some interesting insight on compression ratio, cam size, HP, and torque, check out this build up of a Chevy/GMcorporate SBC 383" crate truck engine which uses the stock iron heads with smaller 1.94"/1.5" valves throughout each step to reach 460+HP and 500+ lb.-ft. torque (although it may be a slightly 'happy' dyno they used):

GM HT383 Crate Small-Block - Engine Build - Hot Rod Magazine