VH45DE: Hidden Beauty of Intake

[Raxephon]

I was mucking around in my "office" the other day and snapped a few pics.

It really is amazing how nice the intake manifolds and plenum are designed, you just don't appreciate it as much when its installed in the "valley" compared to having it assembled outside of the engine bay.

I haven't seen anyone else post pics of the intake manifolds & plenum assembled outside of the engine bay, so I thought I would share.

[Ezekial]

nice photo's ...

who hacked the bottom runners on RHS bank?

[Raxephon]

nice photo's ...

who hacked the bottom runners on RHS bank?

That good sir, would be me.

I'm experimenting with improving the flow characteristics by eliminating the siamese ports in favor of singles.

Yes, I know it looks horrible, but I just started it, so it isn't even 10% finished.

[Mettler]

Definitely a very nice intake design ! Cheers for those pics, it looks great.

(And my VH41DE also has this intake manifold, just in case anyone reads the thread title and gets confused )

[Raxephon]

Its also pretty nice inside the plenum as well. (Smoothness)

(Sorry, I haven't cleaned it out just yet.)

(Sidenote: The following picture details why I hate emissions equipment)

[Mettler]

Is that because of EGRG ? My VH41 is totally clean inside the plenum, check it out.

Wondering whether mine doesn't do the same thing!

[maxnix]

Here are the lower runners on my VH41DE with about 80K miles.

Difference is due to the EGR tube in the plenum and its two orifices on either end. More of the EGR flows to cylinders 3, 4, 5 & 6.

[Raxephon]

Is that because of EGRG ?

Yeah, the EGR Valve is the main culprit, PCV Valve adds to the icky-ness.

For the PCV Valve I just added an oil catch can, but there was no getting around the EGR Valve without completely removing it. Just for reference on how much I despise icky-ness, heres a pic of the valvetrain components from one of the cylinder heads that I'm rebuilding.

[Mettler]

Ewww, your VH41 has the **** intake manifold >_<

Hmm, I might look into removing the EGR system from mine... never really thought it was necessary, I asked about it a long time ago and Q45tech made comments in relation to highway MPG etc, but since my setup's custom and will be custom tuned, I don't think there's gonna be much unburnt fuel going to waste, nor power loss.

[elwesso]

man those are GREAT pics!!! Its like they took one of those indy car manifolds and twisted it 90* so that it would fit under the hood of the Q

What are you doing to your heads? Just a basic rebuild, or any goodies (new cams I hope wiht some beefier valve springs)

[Raxephon]

....What are you doing to your heads? Just a basic rebuild, or any goodies (new cams I hope wiht some beefier valve springs)

At the moment just a basic rebuild along with some slight modification to the ports. I'm content with the stock cams, *at the moment*, but I'm definately fond of the idea of beefier springs and a set of inners. I just can't seem to find a set of inners.

Not sure what I might decide in the next couple of weeks here, but I do know that I'll be pretty damn busy.

(M/T swap in my P10, KA Rebuild in my S14 along with brakes/diff./bodywork, Re-upholstering the black Q, Rebuilding the bottom end in the black Q, adapter plate,KA transmission rebuild, etc...,etc...)

[Ezekial]

search the gtir forums ... even in oz ... worse case ... get it mailed to me and i'll send them over for you

mine were $50 for 32 ...

[defrag010]

sweet, you work at a machine shop too?

[Raxephon]

search the gtir forums ... even in oz ... worse case ... get it mailed to me and i'll send them over for you

mine were $50 for 32 ...

I didn't even think to look on the Australian forums. Thanks!

sweet, you work at a machine shop too?

Part time, but the owner is nice enough to let me come in after hours and work on my own *stuff*.

[Ezekial]

thats $50 AUD also ...

[elwesso]

dude if your gonna go to the trouble of rebuilding your heads yo uneed to get some nasty cams reground... might as well with all that stuff out, and shouldnt add a ton of $$ to your project.

[Mettler]

Yeah man, elwesso speaketh the truth !

A decent NA cam grind on a VH is the easiest 400+ HP you can get.

[elwesso]

I bet that the stock exhaust manifolds on the 45 would do pretty good with cams. Obviously custom equal length long tube headers would be much better, but I bet youll see great gains with just the cams....

plus with that thread about the different cam stuff, you should be able to find a spring/retainer to run .45in lift.... Only problem is you may need to have the pistons flycut a little more, but that shouldnt be hard since you already have all this taken apart.

[Mettler]

According to Mr Hartley here in NZ, he does cam grinds that increase the lift and duration, with no piston interference issues. I dunno how much more lift you get, but I'll find that stuff out.

[defrag010]

heck, you should do the drop-in dodge spring/buick retainer that I documented!

[elwesso]

According to Mr Hartley here in NZ, he does cam grinds that increase the lift and duration, with no piston interference issues. I dunno how much more lift you get, but I'll find that stuff out.

is this on a 41 or a 45??? Im not sure if the 41 clearance is the same, but it should be because they have similar compression ratios... Just something to think about, if you could find that out that theres no flycutting of the factory pistons needed for some higher lift cams, thatd be swell!

[Mettler]

is this on a 41 or a 45??? Im not sure if the 41 clearance is the same, but it should be because they have similar compression ratios... Just something to think about, if you could find that out that theres no flycutting of the factory pistons needed for some higher lift cams, thatd be swell!

Either/or. He advised me the valvetrain is identical on both, as are the conrods.... he has a VH50DE running his cam grind, and I'm pretty sure he mentioned his extra stroke being an offset grind on the crank... it works mint! To do a 4.5 swap all you need to change are pistons and crank (and obviously bearings).

[elwesso]

i thought the pistons were the same, but the stroke was just smaller.... guess not?

also if you can figure out how much lift he's running thatd be really helpful!

[maxnix]

Pretty impressive!

Why are you rebuilding the heads?

If you don't prefer the siamese intake ports, why not go to the later single port design? According to Q45tech, airflow restriction on either is neglible.

[Mettler]

i thought the pistons were the same, but the stroke was just smaller.... guess not?

also if you can figure out how much lift he's running thatd be really helpful!

Nah man, same conrods.

If you think about it there's only 50ccs difference per cylinder made up by a 6.7mm difference in stroke. The crank has this extra throw on it, and the compression height is moved up by the same amount on the 4.5 pistons.

Stroke isn't dependent on rod length.

[maxnix]

Nah man, same conrods.

If you think about it there's only 50ccs difference per cylinder made up by a 6.7mm difference in stroke. The crank has this extra throw on it, and the compression height is moved up by the same amount on the 4.5 pistons.

Stroke isn't dependent on rod length.

So the VH45DE has a higher deck? Doesn't appear so in the engine bay, but that's sure not definitive.

[elwesso]

So the VH45DE has a higher deck? Doesn't appear so in the engine bay, but that's sure not definitive.

It wouldnt have to have a higher deck (it might but i doubt it).... The offset on the crankshaft is just less.... I was having a momentary lapse of the obvious, but thanks for clearing that up Shaun!!!

BIG NASTY CAMS, HERE WE COME!!!! With a set of cams with appropriate supporting componets, an 8000 redline in a NA VH sounds pretty tasty

[defrag010]

Who is everyong getting to grind their cams? I think I'm going to use Delta Cams

[Raxephon]

dude if your gonna go to the trouble of rebuilding your heads yo uneed to get some nasty cams reground...

If she was staying N/A I probably would

heck, you should do the drop-in dodge spring/buick retainer that I documented!

I'm seriously considering it.

Why are you rebuilding the heads?

If you don't prefer the siamese intake ports, why not go to the later single port design? According to Q45tech, airflow restriction on either is neglible.

She will be getting a supercharger, a manual gearbox, and a few add ons. I'm also going to enlargen the intake passages a bit over stock to allow less restriction. Even a little less restriction will be a benefit for me.

[Mettler]

So the VH45DE has a higher deck? Doesn't appear so in the engine bay, but that's sure not definitive.

Nah the deck height is the same, just 6.7mm more stroke on the VH45 crank, and 6.7mm reduction in compression height in the VH45 pistons. Same deck height, same conrods.