Horizontal Intake OMC V-4 Cross Flow

**navigator125** · 11-29-2009, 05:18 AM

The intake is a 2 piece part. I used a front half off of a V-6 Merc and choped the bottom to barrels off. Then welded the casting to what was left. I am explaining this very simply. There was a lot of detailed work involved in this system. I hope all these pics help yall out. Once again the Urban Legend is out there and it does run.

**powerabout** · 11-29-2009, 06:23 AM

Nice job!

**EMDSAPMGR** · 11-29-2009, 06:24 AM

Nice work! You have gone through some excellent planning and have it well thought out. Any idea of your results? Do you have any comparison perf data or dyno comparisons to show what you got for your efforts? Did you have to go up in prop size? What carbs and jetting are you running- 1 3/8". What rpm's does it pull now vs before?

**Jason Johnson** · 11-29-2009, 07:19 AM

I am a Yamaha man to the core, I have seen three for a V4 Yammi. always been told that it was a killer piece. Congrats for you going through the hell involved with getting it done. Get it perfected and have it cast. The OMC boys are gonna love you.

**mcyama** · 11-29-2009, 08:38 AM

Very well done!! I wish that my Yammi one came out that nice. Looks like you did it right. Once again hope to post yammi pics today. thanks martin

**MattGreen** · 11-29-2009, 11:13 AM

Tell us more about the gains you've seen....
Is the motor ported to take full advantage of the new front ?

Matt

**baja200merk** · 11-29-2009, 11:43 AM

Nice work!

wheres laker when you need him? i see a v4 crossflow vs looper battle coming

**navigator125** · 11-29-2009, 11:57 PM

Currently running 1 5/16" carbs with 73 mains. Next step will be the 1 3/8" and after those get set goin to 1 1/2". Do not dyno any of my motors. This set up has increased the amount of pull and the mid range is alot fater and stronger. I would guess this added 20-30 HP. The only part on this configuration that can be cast is the pattern for the reed boxes. Everything else has to be welded and machined. There is 1 casting that was kept to the side so more can be made if needed. Can't wait to see this setup on the next project of a totally build out V4 cross. I think that will be this winters project.

**BarryStrawn** · 11-30-2009, 08:47 AM

That is good work. Now it needs a slider front and EFI.

Did you give any consideration to using an "X" configuration like the factory race V6? It would seem to be a similar effort and the carb to reed manifold is radically improved.

**racervboat** · 11-30-2009, 06:54 PM

You guys ever see the inside of a factory KR racing motor?

**BarryStrawn** · 11-30-2009, 07:14 PM

Originally Posted by racervboat

You guys ever see the inside of a factory KR racing motor?

Yes. Been a few years.

**racer** · 11-30-2009, 10:05 PM

Yeah been in lots of them but like Barry been awhile

**Laker** · 12-01-2009, 12:53 PM

Originally Posted by baja200merk

Nice work!

wheres laker when you need him? i see a v4 crossflow vs looper battle coming

Oooh Bring it on! HEHE
Jeff baker did a Front half the same way and put merc carbs on his Xflow.
His ran pretty good

**navigator125** · 12-01-2009, 11:27 PM

The only thing with Jeff Baker's is that was not a true X front like the CCC. It was a horizontal reed front but the reeds where off set. This set up the reeds are horizontal and centered. The reed used where fiberglass reeds from a Merc SST120.