Intake for 3.8

[JoeMag]

For a 3.8, besides ITB's, what is the next best intake to use?

[CBRacerX]

Signing up for this one!~

[Steve@Rennsport]

Varioram, of course. (N/A, only)

LOL,.....The real answer depends on the engine's configuration and expected RPM range.

We have been working on several options (EFI) for different motors and applications and many of these show real promise, both on the dyno and on the track.

I'll have pictures when the R&D process is complete.

[CBRacerX]

Keep the info coming Steve, glad to see you back on the keyboard (and even more importantly in the shop!)

[JoeMag]

Mine is 3.8 RSR engine (at least heads, p/c's, cams, case, ...crank is evo), going to red line ~7.2k and going to use Motec. It has sprint heads but I hear they don't last long so probably going to change to 3.6 heads... So there's the basics.

Now, based on the above, along with intake question, what's recommended heads -- intake, exh port sizes and valve sizes. Don't want an engine I'm rebuilding at end of each season.

[Lukesportsman]

Where the weak points in the Sprint heads? Are the guides too thin or the valves designed for max flow over durability? Certainly the alloy isn't inferior to a production head?

Money no object: CMW or Ninemeister. I'd love to see a side by side comparison. Sadly the 9meister billet heads make the CMW's look like quite the bargain. CMW's were developed first yet seem to be mostly in-house ideas that came from their own porting and welding of factory heads (not condemning in any manner). 9meister's were developed using outside sources familiar with most recent F1 tech (not necessarily more appropriate for our application with ancient architecture locked in). Just based on cost, I'd have to go with CMW at just over a third the price.

CMW's on top of some LN eng Nickies would be beautiful with an EVO crank and cams spinning within.

[JoeMag]

I've heard it's a durability thing. Heads are really shaved a lot out of the box.

I hadn't seen the CMW heads before, they're pretty nice, however, thats a lot of $.

[Lukesportsman]

About $4200 a set finished, no core. These are with uprated components but yes serious money for serious engines. Sounds like yours might be a serious effort. Just curious, how much did the Sprints lift you of in the wallet? The Brits bits are like $12k I think so its relative and I'm glad were in America. Shoot, did you know we get Jaguars for the less than they do, by a large margin in some cases.

Shaved to reduce combustion chamber? How does this effect the chain length? Or did you mean something else that a non P-racer isn't catching?

[Lukesportsman]

Bernard asked me of ways to find out more on these head options. I guess I just dream more than some. Here are some links you might find interesting:

http://www.ninemeister.com/site/27.html

From Colin's website
qoute:
The ultimate specification engine would see a build cost of around £30k, taxes permitting. It is not just a motor rebuild, its £30k for the ultimate race engine which includes the following custom designed 9m/4T parts:

1. Billet EN40B Stroker crank.
2. Lightweight steel connecting rod set.
3. 103mm 2618 slipper pistons.
4. 103mm Nikasil cylinders & steel sealing rings.
5. Machined from solid cylinder heads
6. Lightweight 8mm stem intake/exhaust valves
7. Billet steel hollow race camshafts, superfinished lobes.
8. Billet steel followers, special coating to eliminate wear
9. Race duty valve spring/retainer pack.
10. Carbon/CNC alloy throttle body set with airbox.
11. Motec engine management system
12. Set large flow fuel injectors
13. CNC ported/shuffle pinned crankcases
14. Full engine fastener set
15. Remove, strip & rebuild labour
16. Dyno mapping

Qoute:
"We are currently offering a 350bhp kit comprising of the head/cam/spring kit package at £5995 "

The following thread is good:

http://forums.rennlist.com/rennforums/showthread.php?t=252445

Cousimano's CMW
http://www.cmwmotorsports.com/store/product_category_1.htm
993 Bi-Turbo / GT2


Part Number Description
Price (US$):

Inquire Billet Head Bare Inquire
SC1008 Billet Head Street Compelte $847.63
SC1008R Billet Head Race Compelte $936.09

Just thought I share the PM after a little research for others to drool over. This forum is very expensive in deed. As are those Brit magazines that taunt us with their pricey parts.

[briankeithsmith]

The CMW heads look like a good deal to me. Joe, I'd go for that. When I had my heads rebuilt and everything had to be replaced, it ran me close to $3800. So $4500 for a spanking new set of heads (probably with minimal lead time) sound like something I'll be interested in the next time.

Brian

[911teo]

We (well Steve Timmins has built the motor) are using the CMW heads, together with their 3.9 P&C, springs and retainers.
The motor is almost ready. The car not yet.

Here are some pics of the heads


















When designing the motor I was not aware of the Ninemaster set up.
Apparently they have found the magic way to generate a lot of torque by changing the design. It is difficult to really compare their product because on their website they dont just take an engine and swap the heads.

The change to Motec, new cams, new exhaust etc.

Certainly Colin and the others at 9M know what they are doing...

Their 4.0L is putting out 450HP at 7,600rpm. It means that they need to get at least 350lb-ft of max torque.

To give you an idea the 3.8RS put out 273lb-ft (assuming Porsche was a little conservative) of max torque...

At 9M they found and extra 28% between the heads and exhaust. Pretty impressive.

But at $60k it better be!

[briankeithsmith]

Hey Matteo:
Those pics of the heads -those aren't the CMW ones are they?
if you have any pics of the CMW heads I'd like to see them!

Brian

[JoeMag]

Matteo -- Thanks for all the pics, but you're confusing me... I see two different intake port sizes. Here's a few specific questions to what you're going to end up using...

1. What is the intake and exhaust valve sizes?
2. What is the intake and exhuast port sizes?
3. ...the most important question -- why were the sizes to the questions above choosen?
4. What throttle bodies are those and what size?

thx, Joe

[911teo]

Brian
That's right... I had forgotten. I had ordered the CMW heads but they were still fulfilling other orders so I decided to go witht he above Porsche heads.
They have been machined by CMW. Sorry so no pics of the billet CMW ones.

[911teo]

Originally posted by JoeMag
Matteo -- Thanks for all the pics, but you're confusing me... I see two different intake port sizes. Here's a few specific questions to what you're going to end up using...

1. What is the intake and exhaust valve sizes?
2. What is the intake and exhuast port sizes?
3. ...the most important question -- why were the sizes to the questions above choosen?
4. What throttle bodies are those and what size?

thx, Joe

Joe

1) The valves are 52mm and 43mm (RS size)
2/3) The port are 45mm intake and 43mm exhust. I am not an engine builder so I wish more expert people (Steve or Henry)would chime in but as I understand it 45mm is the upper limit with the port.
The limiting factor is the valve. Even if one went with a 56mm valve the curtain area is 56*pi*12.5(assuming valve full open at 12.5mm) or 700pi. The port area is 506pi but you know that the fluid will go through only with valve open and that 506pi is more than enough to guarantee the maximization of the fluid flow.

I also think that 45/43 is what Porsche has done on their big motors.

4) I am using Jenvey ITBs with 51mm tapered down to 45mm stacks.

Motec M600 will control everything and the cams are DC-62 and headers 1.875.


I only followed the advice of people that had much more experience than me.
I hope this helps.

Happy new year to everybody!

[STROSEK]

I have a new set of CMW heads for my 3.8 project.... The machine work is poor and very rough, the contact surfaces are acceptable. Many tool marks and rough edges I was disappointed when I opened the boxes. I don't think this will effect the way they perform but it is worth mentioning.

If they were done at a slower speed with sharper tooling bits they could be made to look MUCH better.

[Lukesportsman]

STROSEK:

Please post any additional pic's.

Looks like you got the "race" heads with they're upgraded seats? I was hoping for more a jewel appearance to the pieces. You couldn't get away with that kind of machining in the street rodding or Harley groups. Sad that they don't look more like LN Nickies. I know we don't see our heads as much as other engines, but I thought these on top of Nickies would yield a real visual marvel.

Hopefully they will perform as promised and everything else will be naught.

Please start a thread on these as you get it together and running!

Sorry, Joe, we're not getting many thoughts on intakes BUT you'd have to know your heads first to maximize other choices so this makes some sense.

[STROSEK]

I will be using LN cylinders and like you was hoping for MUCH better. I purchased billet valve covers from Imagine Auto and they look great theres no reason for such poor workmanship from CMW. Good from far but far from good!!

Here are some other pics...

[Mahler9th]

I thought this question was about intake... not heads??? Anyway, my 3.8 uses a 993 plastic intake. I use the plenum flapper by controlling with an rpm switch.

The engine has run rsr cams, but this winter we have added something a little more aggressive.

I have a BBK 80mm throttle body adapted to it, and a cf cold air box I fabricated. Before the custom box, the intake used a flat bmc filter inside a modified 993 airbox (which is for sale by the way).

I expect 360 + or - 10. Car weighs 1950 and is "street legal."

I have considered: ITBs by twm, slides, and a few other things, but I have not yet decided to move toward an 80000 rpm/20 hour motor. I think I will skip buying a commercial product and try to convince my friend to fab up some slides... that might be fun.

[CBRacerX]

Originally posted by STROSEK
I will be using LN cylinders and like you was hoping for MUCH better. I purchased billet valve covers from Imagine Auto and they look great theres no reason for such poor workmanship from CMW. Good from far but far from good!!

Wow - these are a far cry from how their heads used to look. Sorry to see this.

So, what cam towers are you using with the Imagine auto valve covers? I would be interested in seeing them if they are for the 964 type (or even if not).