ITB! Do it!

I didn't open up the exhaust ports on the head any. They already matched the OEM exhaust gaskets and the headers. But, just a rule of thumb, if the headers are slightly bigger than the exhaust ports on the heads, you don't want to match them. It's best to leave the exhaust ports the size they already are since that small lip will help exhaust gases from being sucked back into the head. It's minor, but something I kept in mind while porting my heads.

 

Speaking of ITBs, look at these guys:

http://www.extrudabody.com/
and:
http://extrudabody.com/Products/ITBs.html

and three views of a VQ35 ITB:

http://s307.photobucket.com/albums/n...tDBC_1523c.jpg

http://s307.photobucket.com/albums/n...tDBC_1525c.jpg

http://s307.photobucket.com/albums/n...tDBC_1525c.jpg


Reminds me of LEGOs.... now if I can find a price....

.

 

How's the build coming along?

 

It's been on hold for about a month - other business to tend to first. Had to get another transmission for the Shark and take it out to play....

 

That's one sick engine.

You dont do thing half way... Good stuff very impressive.

AA

 

Yeah, this engine will be ... special ... but it's nothing compared to the car you're building. Just reading your thread wears me out - that's a tremendous amount of crafting and plain old hard work there. What you didn't paint, you chromed.

Hummm... the only improvement I can think of is to build a Cosworth-based 3.5 L engine for your car !

 

That would be sick but I got to finish this one first. Today we removed the rear axle and separate the 3 parts so I can bring it to the sandblast shop tomorrow, then it will be painted Metallic black and all the bolts will be chromed. I'm also bringing my AT at the paint shop tomorrow but I'm still not sure what color I want it tough. I guess I'm too tired to think, so got to go crash. Talk you soon.

Cheers and keep up the good works

AA

 

Nice Build !

 

Cosworth is shipping me a replacement set of cams (don't ask) so I can get back to building this engine. I was just starting to degree the cams and encountered a problem, spent some time corresponding with my vendor BoomBop and Cosworth, shipped the whole set of cams to California, and heard yesterday that they are replacing the set. In fairness to Cosworth, I think they got stuck with bad metallurgy from their cam manufacturer.

BoomBop is a class-act vendor. So far I've purchased my forged CP pistons and Cosworth ZK2 cams from them, and they have handled every part of the transactions with a professional can-do attitude.

 

Updates?

 

It's not raining today - and I have one pair of cams installed....

 

Now that's wassup.

ETA?

 

This fall.......

I just went out to a new digital truck scale and weighed the max - 3540 lbs. with me inside, 1/3 tank of fuel, and two full nitrous bottles sharing the truck with the sub and spare tire & jack. This is the Shark's fighting weight except I had the BFG DRs on instead of the M&H slicks - that might be 40 lb lighter.

The '03 Frontier tow truck weighed 4600 w/me, the Frontier with me and trailer weighed 6840 together, so putting the car on the trailer means I'm rolling at 10,140 lbs - plus all the tools, floor jack and crap I put in the truck on a track day. I roll pushing about 10,300 lb - no wonder I get 7.5 MPG!

I'm glad gas is back in the $2.30 range now.

 

Lol goodluck with the new setup & I hope you dont break *anything



*(Expensive)....lol

 

Ha! I already broke everything important once or twice - time to start over..... I just received a pair of American AR-23's 15 x 8 wheels to re-mount my 24.5 x 15 H&H slicks. They're on a pair of real lightweight M/T 15 x 10 wheels - which are too wide!

The slicks are ripping themselves up on both the inner and outer areas of the tread. Really weird. The 23" M&Hs on 15 x 8 Outlaw IIs have OK tread, so I guess I should follow the manufacturers recommendations on rim size.

"it's always something"

.

 

damn...still at this huh? i have to keep up on your thread lol. havent been on here for awhile!

 

All right - I'm gonna finish this motor assembly this week - had to take a week off work to do that...

Today's work - got both pairs of Cosworth cams installed in the heads, and the custom 3.0 timing gears and such are installed.

Tomorrow I'm going to degree in the cams - mostly to be sure everything is correct. Almost all parts you see are brand new, except for the two small chain guides. If timing is OK, then the outer timing cover, and lower and upper oil pans are next, along with the rear main seal, and of course valve covers.

Somewhere in between all that, I have a bell housing salvaged from a broken transmission, and I have a new starter in the mail, so I plan on spinning this engine over with oil in the pan to be sure everything is working before transplanting it into the car.

 

Seal her up

 

Don't I wish? Soon - very soon......

 

I started off the day setting up the degree wheel - then decided to check the valve lash on all cam lobes, so I knew how I stood with valve clearance on the second set of Cosworth ZK2 cams. Not so good - the original valve clearances were set at .012-.013 by a machine shop, first doing some valve lapping and checking all the valve stems for correct height. Remember I had to buy a complete set of the special DLC HR lifters for these cams.

With the new cams replacing the cracked cams, I have valve clearances of .006" to .011" - only four of the 24 valves have acceptable clearance, and they are on the tight end of acceptable. So, I have two choices here. Since I have a complete list of the clearance on every lifter,, I can either try to dremel down the clearance bump on the underside of each lifter, or I can take the list and the lifters back to my machine shop and let them do it. I'll go visit them tomorrow and see what Steve thinks about this one.

Of course I tried the dremel on an old-style 3.5 lifter and I was able to remove .006" rather easily. The bump is made of some hard stuff, so it takes a while to get 'er down. This is do-able!

Bummer.

 

SO the verdict on these cosworth heads is that its not worth the money?

Seems that they have been giving you a bit of trouble

 

seriously its just issue after issue with them, glad someone tried them out though

 

?? Huh ?? Building an engine like this takes very close attention to all details. What screwed me up was the first set of Cosworth cams developing cracks - getting those replaced took a lot of time and conversations with the manufacturer and distributor.

There are no better VQ35 heads on the market. The Cosworth ZK2 cams were designed to work with these heads. Put the whole package of my built short block together with the Cosworth heads and cams, and you have something special to spray nitrous with.

 

but with all the post modification that needed to be done to the heads, would it not have been more advantageous to just have a shop basically duplicate the work cosworth heads?!

if this was asked before sorry...have scrolled thru the thread in a while..

 

Got ya on the part about wanting to make sure everything is correct and making sure you have optimization for everything you want to do, but like Mdeezy said...would the advantage of taking it to a shop and saving say $2000 and having the heads matched to the cosworth specs or identical to them, would the juice be worth the sqeeze then?

 

Cosworth heads are new cast blanks to Cosworth specs though, they cant be 'copied' or replicated.

However, I have been looking at some Nismo 46cc VQ35 heads which use the VQ30 combustion chamber design and reportedly outflow the Cosworth heads once oversize(Cosworth or Supertech) valves are fitted.
http://www.nismo.co.jp/en/products/c...ne/vq35de.html

 

with all the money shoved in to the heads, you'd think they'd come back flawless

Here's what the flowbench numbers of my head work is.

Stock - 188.8 @ .200"
281.2 @ .500"

Ported - 228.9 @ .200"
318.7 @ .500"

There's a guy down here that does some of the best porting.
About a 37.5 CFM gain, which should be around 50hp on the top end and you can see there 40.1 CFM gain on the low. So if each CFM = around 1.4 HP you can see that the headwork alone will post around a 50hp increase

 

$2,550 for the spec 2 heads which ahve the oversized valves is not bad at all.

the high compression is not what i want but I could just get lower compression pistons to counter balance it.

 

good info! Maybe I should look into some porting...

ohh okay didnt know that...thought they took DE heads and built them up from that...

 

Wrong - the heads haven't been modified since Cosworth CNCed the Nissan blank castings, installed the +1mm stainless and inconel valves and installed the $1,100 dual valve springs and titanium retainers - except the only mod made was to tip off the valve stems and do an insurance lapping of the valve seats. The outcome is a head with flow numbers in the 420cfm range.

http://www.cosworthusa.com/store/pc/...7&idproduct=68

http://www.cosworthusa.com/store/pc/...nt%20tests.pdf

Anytime you install new competition cams, you have to find compatible valve lifters and do exact measurements of the valve lash on each valve so you can buy the appropriate size of lifter. I had to do it twice since the first set of Cosworth cams developed cracks after installation.

If I thought any shop could have created a comparable set of heads for $4,000 with all the CNC work, valves and dual springs, I would have been there. ( well, maybe Aaron could have done it..)

Maybe some of you guys haven't done this before?

 

yea, I already stated I didnt know the cosworth were casted from blanks, I myself thought they were DE that were examine R&D'd and re-machined to their spec to flow out the numbers they stated.

We are just making suggestion/getting more information. I'm not sure about the others but i'd think for what you spend on those heads you should have zero problems with them. If the heads arent the problem then forgive me I'm mis-interpreting the problems at hand...

either way...good luck and looking forward to the completion

 

To be honest no, nothing this extensive and its all new to me as I am trying to learn about all of it as much as I can.

Thank you for the info, it helps to learn these things ahead of time

 

as you know Grey you are the first to buy these heads... I havent even seen anyone on my350z pick these up...so naturally we are here to watch plus learn all we can..

 

Cosworth makes great ****. Hell they made a VQ30 make 450hp at 8000+ rpms.

From the research I did back in the day, these heads are awesome. Anything this custom is gonna have lots of custom work, it will all be worth it in the end. At least you are doing it right

 

And that, sir, is the whole point of this thread.

 

We will all learn together, then. The level of detail work required here has been much higher than I expected - but that's normal for me. I'm a slow learner, but I'm persistent. I "endeavor to persevere".

.

 

I should add that the VQ30 with over 450hp was NA

 

Somewhere here I have a flowbench graph of these Cosworth heads. I'll post it for your comparison if I can find it... scary numbers even at low valve lift numbers.

 

I'm a lil confused as for the price.

Aren't the heads $4000+ and the cams and valvetrain extra? I didn't think the heads come complete for $4000. I always thought the heads+zk2 cams+valvetrain= $6500ish

 

Look at the Cosworth links on my posting above - OEM prices and features are shown.

You're kinda right - normal price on the heads is around $4,600 with the valve train ( special +1mm valves. dual valve springs) installed. The ZK2 cams are normally $1,400 from most distributors.

I got deals on the heads and cams. $4,000 + $1,100.

The DLC HR valve lifters are $17.38 each and you need 24 of them. That adds another $430 to the price. Then you need intake and exhaust manifold studs because they're not included - about another $100 for stainless.

Finally you need a machine shop to top the valve stems and measure valve clearances for each valve (you don't know which size lifter you need until this step is done). Thats another $300-$500. It goes on from there - you gotta get all those new parts all installed and working together. Whew.

Then there's the rest of the engine.... I just my new starter this afternoon. I have this bell housing, so my plan is to finish the assembly once the HR lifters are trimmed to fit the new cams, then crank it over and measure the oil pressure and look under the valve covers for circulation.