RamJet intake manifold to head port matching

[Kitch]

I've just removed the 5.7 Vortec crate engine from my 93 G20 conversion van.
I'd fitted a RamJet MPFI setup onto the 5.7 and I'm going to replace the 5.7 with a BP383 Vortec replacement crate engine.

I was looking at port matching the Ramjet intake manifold the 383's alloy heads, I made a paper templates of the ports in the heads to scribe on the intake manifold face.
I thought I'd just have a quick look with an inspection camera to check the alignment, when I noticed the roof of intake runner seems to partially obstruct the cutout in the intake manifold for the injector.
I need to play around a little more, as the obstruction might not be quite that bad but regardless it will still be there.
I'll also need to put the RamJet manifold back on the 5.7 and check the same thing out.

Has anyone noticed this before?
Should I blend out this obstruction in the intake runner?

[tayto]

clean up the casting flash and call it a day. port/gasket matching is generally a waste of time unless you are changing how the runner works. you will see way more benefits in pocket porting than port/gasket matching.

[Kitch]

I get what you're saying and that certainly applies with a stock head.
The advertised flow numbers on these alloy heads are pretty good out of the box and I wouldn't pull them off a new motor just to clean up some casting flash.
I don't normally bother with port matching the runners but the Ramjet intake port is noticeably smaller on one side of the runner and the floor of the runner compared to the port in the head, enough that I think it might create some flow problems. The abrupt change in runner size from intake to head could create some turbulence, it's also relatively easy to get to at the moment.
My question is probably more about removing or leaving the small lip that potentially obstructs the injector spray pattern?

[tayto]

if you want to invest the time go for it but I don't think the gains will be as significant as one might think. usually you leave the floor of the runner alone unless you are changing the shape of the runner which is fairly advanced head porting. pull a set if valves out and check how it transitions from the valve seat to the runner. a lot of stock stuff has a ledge here. grinding and smoothing this transition and you will see much higher gains here than port matching.

if you want to get a gasket that is a better match for the port try a felpro 1255. i also have a borescope that i stick down the runners before tightening the intake down. this will allow you to "split the difference" and centre the port as best as possible to the port in the cylinder head. the vortec intake has almost 1/8" of play it can move front to back before tightening down!

[Fast355]

if you want to invest the time go for it but I don't think the gains will be as significant as one might think. usually you leave the floor of the runner alone unless you are changing the shape of the runner which is fairly advanced head porting. pull a set if valves out and check how it transitions from the valve seat to the runner. a lot of stock stuff has a ledge here. grinding and smoothing this transition and you will see much higher gains here than port matching.

if you want to get a gasket that is a better match for the port try a felpro 1255. i also have a borescope that i stick down the runners before tightening the intake down. this will allow you to "split the difference" and centre the port as best as possible to the port in the cylinder head. the vortec intake has almost 1/8" of play it can move front to back before tightening down!

The 1255s and Edelbrock 170cc runner gaskets fit stock vortec ports well. The GM Fastburn or Edelbrock 200cc Etec gaskets fit the Lloyd Elliot ported ~210cc heads on my Express van weĺl.

[Kitch]

I've now ported the Ramjet intake to better match the BP383 intake ports.
Every-time I was checking with the gaskets in place and intake manifold torqued down, moving the intake forwards before tightening down seemed to be the best compromise for runner alinement.

While the runner width is now better matched, the lip at the top of the runner partially blocking the top of the injector was bothering me.
So I masked up the heads and ported a small radius into the roof, I only needed blend it back about 1/2" into the runner.
As you can see from the photos, it's a clearer shot to the back of the valve now.
It would have been interesting to check with some Felpro 1255's but I didn't have any, I only had some 1289's and they were too tall.