omc intake manifold rubber fill blocks

[Palmtreeguy]

Hey guys, what purpose do the rubber fill blocks next to the reed cages serve? Ive seen them on v6 crossflows. Do they offer any preformance benefit & if so will they work on CF V4s?

[MTOLLEY]

They are used for stuffing, taking up unused volume and yes they are a good thing

[EMDSAPMGR]

The rubber intake manifold filler blocks take up wasted/ecxess crankcase volume. Improves the intake side compression and improves performance. The high perf crossflow engines used them. That included the 200/235/2.6 V6 engines and the 140 V4's starting around 1977. The V4 blocks are not the same part number as the V6 blocks. You'll get 3-5 hp more from a V4 and 5-8 hp more from a V6 with the blocks. The V4 part number is 322684

[omcforever]

I make my own. I buy the angled gas resistant rubber stock from McMaster Carr and just cut to length, insure there is a couple thousanths inch interference fit and they work like a charm. Those original pieces are very scarce,,,,

[smythe302]

Any chance someone could post a picture of these suckers?
Thanks!

[EMDSAPMGR]

[DanUmbarger]

I have a 1975 135 Johnson...would these help with this motor...if so do you have a part# from McMaster Carr...I have purchased many items from them in the past and am not sure exactly what your looking at....thanks....Dan

I make my own. I buy the angled gas resistant rubber stock from McMaster Carr and just cut to length, insure there is a couple thousanths inch interference fit and they work like a charm. Those original pieces are very scarce,,,,

[omcforever]

I have a 1975 135 Johnson...would these help with this motor...if so do you have a part# from McMaster Carr...I have purchased many items from them in the past and am not sure exactly what your looking at....thanks....Dan

Factory 135 should already have em in it.

[DanUmbarger]

In looking at the parts books...it appears that the first V4's with the stuffer blocks were the 1977 140...unless they just didn't show them in the parts breakdowns. I haven't taken the intake off so not sure if the 135's had them or not. I rebuilt the carbs after I swapped trim / clamp brkts and the motor sounds nice and healthy. Gonna wait on any more mods till I install it on the Hustler restore job and run it.

Factory 135 should already have em in it.

[DanUmbarger]

If it doesn't end up having them...do you remember the part numbers of the rubber from McMaster Carr or what exactly they called the rubber? That way I can always make them and install them at a later time.

Factory 135 should already have em in it.

[wrechin2]

I have 9 of these still in useable condition as they get somewhat deformed being sandwiched. 7 of them are the newer style and 2 of the older thicker style. $35 shipped (or make offer) for all of them in lower states.