Early vs Late 4AGE-20V Silvertop Intake ports

[s24a]

Somewhere on this or maybe another 4AGE forum there was posted a picture of the early (1991 up to 1993.5?) Silvertop intake port face versus the later (post-93.5?) intake manifold port face.
There seemed to be a substantial difference in the shape of the ports at the flange IIRC.

If anyone here knows where I can find either pictures of the intake sides of the two version heads or that actual picture, can they please either post them or the links for me?

I have been trolling the interent for the past week or so unsuccessfully trying to find them.

Thanks in advance.

Hank

[jdm86gtz]

I can't remember which one is the earlier type manifold

https://www.google.ie/imgres?imgurl=htt ... MwgnKAgwCA

Or the top one in this picture. (bottom manifold is from a blacktop)

https://www.google.ie/imgres?imgurl=htt ... MwguKA8wDw

[s24a]

Good pictures of early (top link) versus later (top piece bottom link) intake manifolds.

However, I am looking for the cylinder head pictures that shows the mating surface that these intakes attach to.

I know they are out there, just haven't found them yet.

If anyone has photos of the cylinder hear intake port sides of their Silvertops and could post them, that would be apppreciated very much.

[jondee86]

Maybe it was this one...



Pics come from here... http://www.billzilla.org/4agmods3.htm

And Bill has this to say about them...

Here are the two 20 valve inlet ports, the silvertop on the left and the blacktop
on the right. The silvertop is dead stock and the blacktop has had only a light
clean-up to get rid of the bumps in the casting. You can see down near the valve
seats that the blacktop has better dividers to each valve.

Cheers... jondee86

[jdm86gtz]

According to the EPC there is only one 20v head available from '91 to '95 11101-19365

[jondee86]

Some differences in the intake manifold itself, according to this...


http://www.my-acoustic.com/Car/vacuum/4 ... vacuum.htm

Cheers... jondee86

[yoshimitsuspeed]

I have only heard of one style ST head and one style BT head. Never heard of different variations.

[oldeskewltoy]

not head... but intake manifolds have some difference as jondee shows



here is my version from about 8-10 years ago... top is early silvertop, middle is later silvertop type, and bottom is blacktop

[s24a]

Interesting that only one type head is listed.
I swear that I saw a picture once of an early and late Silvertop head that showed the early head had the upper injector opening somewhat more "pinched" in the port. If so, that would have more emulated the intake manifold profile except not sharp edge like the manifold shows for the opening profile around the injector pocket.

Maybe I'm dreaming, but if so, that would be a better matchup to the early intake and result in less turbulence that could affect the ISC idle performance.