SOLVED: L-jet Runner Differences

[ClayW]

Is there a difference in these two types of 4-zyl L-jet runners? They seem to have the same diameter, but obviously different castings. Same or different?

 

[Ajay]

One of those looks like an e21 runner. A good upgrade. I used the same on my motor.

 

[lloyd]

Is there a difference in these two types of 4-zyl L-jet runners? They seem to have the same diameter, but obviously different castings. Same or different?

As best I can recall, the runners are basically the same. Extra material can be carefully removed with grinder.




https://www.e9coupe.com/forum/threads/anybody-else-do-the-e21-intake-runner-conversion.4258/


One of these vehicles may employ e-21 intake runners. (But maybe not.)

 

[Ajay]

Clay,

Used the same e21 runners on my motor and they fit fine. Havent tried them yet bc the motor is not in yet...but have high hopes.

 

[ClayW]

Solved: The right is from a 2002tii. The left is from an early E21.

I’ve been collecting them for a while for EFI on the E3 and have amassed 14 of them. It seems that I have 7 tii and 7 E21 runners.

 

[lloyd]

Your initial post left me to assume that your were concerned about "basic" interchangeability between the pictured manifold runners, and whether the differences were merely cosmetic. (Curiously, the parts book describes these runners as "suction pipes" and "intake tubes.")

FWIW, typical E9 runners are PN 11611256567;
E21 runners come in two flavors: PN 11611264725 and 11611264723 and
2002 tii runners(metal) are PN 11611251348

I would not try to dissuade anyone from experimenting with different sized runners. Nevertheless, one wonders why none of the the factory M30 (six) engines used the same E21/tii runners.