Fins on back of Valve & Fins pre TB

[vlad01]

Can be a lot of strange things from the OEM's, but there is normally a reason.
The only one I can imagine for this is that maybe at cruise or mid load there was some uneven cylinder filling and this helped to balance it out a bit and was a reasonable compromise across the entire rev and load range.
WOT runs are only one a small snapshot of a vehicles running conditions, OEM's spend a lot of time working on driveability, especially in the areas a "typical" driver is expected to spend a lot of their time.

well that doesn't concern me then, with the on/off nature of these engines tuned up, cruising it pretty hard work

[festy]

So why was it put there to begin with???

Could be trying to stop the venturi effect where fuel gets sucked out of the front runners when the rear cylinders breathe in?

[immortality]

The bellmouth was to smooth out air distribution, the rear cylinders in particular.

My old VN cruised real well, been gentle with the throttle helps though. I miss that car, was great to drive with the 5 speed, more fun than a V8 with a slush box.

[Dylan]

The VN group a had a similar fitting in there secondary throttle body.

[vlad01]

The bellmouth was to smooth out air distribution, the rear cylinders in particular.

My old VN cruised real well, been gentle with the throttle helps though. I miss that car, was great to drive with the 5 speed, more fun than a V8 with a slush box.

I agree.

driven a couple of 5L autos and was like "something wrong with this, why is it so slow?"

[HQ355]

U'l give you a drive of the Q next time Vlad !

[vlad01]

talking about stock engines

[Gareth]

Frankenfold...




Right.. So the two top halves are actually bolted to the one base via two holes per side (finger tight), next step for me is to cut the runners off the manifold base above the injector bosses and then cut the upper mounting boss off the top of the runners (ill need to cut up two to get enough for this) Then I should have enough parts to weld together.

Some of the considerations for this project are -

Too much plenum volume (easy to add walls to plenums)

Runner lenghts (short runner Vs long runner and how they will work together)

Bonnet clearance

Alternator clearance

What to do about the MAF

And many more things I haven't yet though of, if anyone can see any problems with this, please don't hold back.

[vlad01]

I looked at the alternator today, I think its a no go, maybe posible to keep the alternator with smaller fabricated plenums of relocation of the alternator.


MAF? 808 conversion

[immortality]

Remount the alternator where the AC pump used to be?