I bought myself a E9TE 5.8 last year and I'm finally finding time to start looking it over. Based on the casting numbers it's likely and 89 or early 90s truck engine (flat tappet cam). I'm going with a carb for my install, not FE. It has sat around quite a while so I will be changing out all the seals and gaskets. While it is apart I thought I would do some mild head porting (which I have done before to 302 heads from the same era) and maybe gain some free flow improvement.

I have removed the exhaust port bumps and started to port match the exhaust side ports somewhat. I would have to remove a lot of meat to open up to the gasket size opening. Don't want to chance that. Can't believe how small those ports are compared to the intake side. Can someone explain the reason for that? I don't expect much from these heads, but every little bit of power is nice to have when needed.

How about the intake side? What do you guys recommend for those as far as porting. This engine is going into a truck so I'm not trying to build a drag car, just looking for a little bit more free power. Might consider changing cam and valve springs if that would be worth the costs and not get to bumpy of an idle.

Also is it a good idea to lap the valves while the heads are off. Engine is suppose to have 20k on it (have no idea), but based on the lack of wear on the lifters I would say that might be accurate. Bored 030 over per the pistons.

Suggestions on a cam change or head work I can do myself?

 

I'll throw a lil' bit of red meat out for discussion.

From everything I've read:

It's a descendant of the engineering architecture that enabled a small V-8s to fit between the shock towers of Ford's small & medium sized cars of the early 60's. They never saw fit to improve it. It stayed basically unchanged as long as pushrod small block based engines were produced.

 

The heads you have are E7TE castings?

The right way to deal with port sizing at junctions is to match the dimensions and location of the ports on either side of the junction by opening up the smaller to the dimensions of the larger. This may or may not be to the gasket dimensions, if both sides are smaller than the gasket then opening up both to this size will actually hurt overall airflow because it creates a larger cross section in what should be a smoothly decreasing port taper from the top of the runner to the back of the valve.

The exhaust ports on these small block Ford heads are unusually small because they were originally designed for a 260 cubic inch motor and really have no business on a 351. As a result you can pretty much do no wrong when porting the exhaust side, blend the bowl area into the port and open it up as much as you dare concentrating on the walls and roof of the port mostly. The intake side doesn't need as much work and is easier to screw up.. for example a polished finish is actually worse than leaving the rough casting finish, so it may be better to leave it alone aside from removing any obvious casting defects. The ports in the in intake may need some work though, try to match the size and location of the ports to the openings in the head when installed, it's common for the ports to be misaligned to the front or back slightly and the runners taper down too much on many Ford intakes and need to be opened up at the gasket surface.

The motor would certainly benefit from a cam upgrade, none of the stock cams yeild anything remotely close to the motors full potential. The Comp Cams 35-238-3 is a good candidate for a carbed 351 and matching valve springs are never a bad idea.

 

Yes these are E7TE heads. I will leave the intake side alone, based on your comments above. You have confirmed that my expectations were on target. Are there other stock Ford heads (easy to come by) that would be better candidates for this engine? I could keep an eye out for them.

Another question if you don't mind. The dish in the piston? I don't know if these are stock design since it is an overbore (rebuilt at least once). The pistons have what I would describe as a rectangular dish with curved ends (curve on small sides of rectangle). They appear to provide valve relief, but I'm wondering if they are stock design or were chosen by the PO to lower compression ratio?

Where the stock pistons dished as described?

 

Stock pistons have a small dish, its needed to achieve roughly 9:1 compression with these heads. It does provide some valve clearance though the valves never come close to making contact with the stock cam. GT40 heads are a solid upgrade with slightly bigger valves and larger ports and were available on '96+ Explorer/Mountaineer 5.0's, the Lightning 5.8, and the '93-95 Mustang Cobra.

 

How is the rotating assmebly....have you taken any measurements?

 

I think it is a good idea to lap all of the valves to make sure they are making good contact. The crosshatch pattern and the ridge ( or lack of one ) at the top of the cylinders will tell you more about the condition of what counts than the lifters, especially since you will be changing them and the cam out.
I would pull all the caps off, (one at a time ,of course), clean and inspect the bearings, Plastigage them, and if they are in good shape, apply some assembly lube to them, and torque the caps back on.
At 20K they should be in real good shape, but now is the time to change them if necessary. Some would probably say to just replace them anyway, and as cheap as stock bearings are, may have a point, but if I were to replace them, I'd upgrade from stock. While you are inspecting them, you can look on the backside of the bearings and you may find they are anyway. I like the Clevite 77's myself.