D0OE intake ports

[travis]

I wanted to get y’alls idea on what needs to be done here on these heads. I’ll make a separate post for the exhaust ports. Other than maybe a tiny bit of shaping on the long turn side, there doesn’t appear to be much I can do with the guide boss. The short turn has a sharp lip that will be easy enough to put a nice radius on. That hackery on the back side of the bowl wasn’t my doing...I just cleaned them up but this is how I purchased them years ago. They have undercut stem 1.94/1.50 valves. If I am measuring in the right place, the throat just past the bottom cut is 1.77/1.36 respectively...about 90-91% of the valve sizes. I’m going to clean up that butchery in the bowls. Do you see any other low hanging fruit here?

[travis]

FWIW, I suspect that these have been ported twice. I’ve had the C9’s and D0’s before, and don’t remember the bowls being this big or the guide bosses being this small. It’s also pretty amazing how much better the casting quality is on these old heads compared to the E5’s and E7’s I have here.

[Carnut1]

Looks to have been bowl hogged. I would clean the butchery and go. If you want 220cfm or more the ssr needs less overshoot and lay back to go with it. The pinch will likely need some work as well.

[PRH]

Looks like they bowl hogged the bottom angle(s) right out of it.

[travis]

Looks like they bowl hogged the bottom angle(s) right out of it.

Is that bad? If so, is there any fixing it short of opening up the valve job/throat even more?

Also...should the PR pinch area be larger than the throat area? Not counting the corner radius’, the PR pinch size is 1.92”x1.16”, about 2.23^2”. The 1.77” throat is about 2.46”, and the 1.94” valve would be about 2.95”. Should I make the PR pinch larger, and how much?

[Carnut1]

Do not make throat larger, making pinch larger may help if you get the rest of the port working well. Having performance goals and combination would help figure out what can and should be done. Airspeeds through the pinch, ssr, roof, will tell you much.

[CGT]

Not sure how rare or hard to come by those heads are, but I would probably send them on down the road and find a non-bowl hogged set if that was an option.

[PRH]

The initial post is too abstract for me.

It’s almost like....... I have these heads here....... how should I port them?
Without any discussion about how they’d be used.

Depending on what you’re doing with them...... they might not need any porting.

If it’s just a science experiment, then I agree starting with a virgin head would be best, so you can determine the proper VJ profile for yourself, and not be handicapped by what someone else has left you to work with.

And then there’s the question about how much time should one invest in determining how to extract the “big numbers” out of those heads........ based on how many sets you’d likely be doing ..........when there are so many cost effective aftermarket alternatives available.

Unless it’s a rules thing....... I can’t imagine it’s cost effective to do anything more than the most basic bowl job on them.

In the long run, I think it would be a better use of time to figure out how to get something like this to work well:
Pretty hard to argue with the price.......
https://www.ebay.com/itm/Performance-Ba ... 2712349163

[JoePorting]

The bowl looks too small to me. When you take a picture, make it so that the picture is looking straight down the valve guide. But like carnut said, the ssr needs to be cut way back.

You really need to start with a fresh valve job so you can see where all the angles are. Then port to the bottom of the lowest angle. I'd try and put the largest intake valve possible within .040" away from the exhaust valve. Make sure not to port into the valve job. I'd use a Sunnen #17258 bit for the intake valve job.

[travis]

These are kind of a science experiment, but I would like to use them as well. Not really looking for “big” numbers...more looking for a broad power range with strong low and midrange power. These will be on a pretty basic 351w in my ‘87 F-150. If they could make 400hp that would be awesome...350hp is probably more realistic and would still make the truck much more enjoyable to drive.

What is the concern with with the butchered bowl? Loss of velocity? Weak low end torque?

If these are useable, I “shouldn’t” have to spend too much on them. They already have screw in studs, guide plates, and roller rockers. 63cc chambers as well. The guides look and feel good, so a mill and valve job and possibly hardened exhaust seats should make them useable.

The plan is to build a solid short block, and use these heads for now. But if they are junk, I will figure something else out.

[superpursuit]

The initial post is too abstract for me.

In the long run, I think it would be a better use of time to figure out how to get something like this to work well:
Pretty hard to argue with the price.......
https://www.ebay.com/itm/Performance-Ba ... 2712349163

I see these heads refer to a Pro Comp interchange part number. Is this the new brand name for Pro Comp?

[makin chips]

The initial post is too abstract for me.

In the long run, I think it would be a better use of time to figure out how to get something like this to work well:
Pretty hard to argue with the price.......
https://www.ebay.com/itm/Performance-Ba ... 2712349163

I see these heads refer to a Pro Comp interchange part number. Is this the new brand name for Pro Comp?

Those heads have no name. They're unbranded. No markings. I suspect they're unmarked Speedmaster or a Speedmaster(pro comp) knockoff

[Carnut1]

I just noticed the intake guides look to have been offset maybe .040" towards the exhaust. That could be good or bad. For sure if they have been offset and bowl hogged the intake bowl on the exhaust side is very thin.

[travis]

I just noticed the intake guides look to have been offset maybe .040" towards the exhaust. That could be good or bad. For sure if they have been offset and bowl hogged the intake bowl on the exhaust side is very thin.

Yeah I noticed that. All of them are like that too. Not sure what that was all about...it doesn’t look like they relocated the valves. Maybe just the way the heads was cast?

[PRH]

I guess you guys never heard of core shift.