My CrossFire Project

[geekinavette]

Mine is sure a loooooong story getting to where it is now...which is currently the engine being pretty much scattered all over the garage! :L What started out as hunting down a vacuum leak and fixing a front main oil leak has evolved into a full cam and head swap. I am going from a hydraulic flat Crane 2050 cam (454/480, .050 specs: dur 216/228, LSA 112, no overlap) and stock ported 76cc heads to a hydraulic roller Edelbrock 2204 (539/548, .050 specs: dur 234/238, LSA 112, 12 deg overlap) and a set of 70cc Edelbrock Performer heads with Crane roller rockers. This is the exact same cam/head combination Edelbrock uses on their EFI crate engine. This will be in combination with the "siamesed" intake manifold that I have been running for a couple of years now.

Just got the cam degreed in last night...and boy did I learn NOT to trust those timing marks! Edelbrock recommends installing the cam with 5 degrees of advance (as most do), with two different crank gears installed "straight up" I measured only 1 degree of advance. I am using the Summit timing chain/gear set...which has three keyways for 0 degrees, 4 degrees advanced, and 4 degrees retarded. With the new set that I got for the hydraulic roller cam (it uses a different cam gear than the flat cam) the crank gear in the +4 position measured 8 degrees of advance instead of the expected 5! There's quality control for ya! I put the old crank gear back on (no difference in the crank gears), same 1 degree of advance when installed "straight up", but the +4 position measures the expected 5 degrees of advance. So now I have to decide on whether to just use the old gear (maybe 20K miles on it) or pitch a ***** with Summit to send me one that is cut correctly (that could be a really long and frustrating process).

Also checked valve-piston clearance last night after getting to the desired cam timing...better than .020" on both valves. No problems there!

Can't wait to see what this thing runs like (after some tuning of course)!

Bill

 

[Toms007]

Sounds like a thrash before leaving for Cleveland............. Sure wish you could make it this year Bill, we'll miss you.

 

[geekinavette]

I wish I could too Tom...blast some toll booths for me!

 

[LT4man]

Bill, with my 30+ years building & rebuilding engines, I would not hesitate to use the "used" crank gear. 20k on an engine hard part is nothing.

Tell me again about the type of intake you are running. I remember looking at your engine. Just cannot remember the particulars about your intake.

Good thing you are checking everything as you go along. Sad to say, quality control ain't what it used to be.

Gonna miss you and your Vette in Cleveland. See you next year.

SAVE THE

 

[geekinavette]

Yeah I imagine the old gear would be fine...but dangit I just can't use and old one when I have a brand new one! Besides, if I have a problem then they won't be able to come back with "well you didn't use the gear provided". I just went ahead and used an offset bushing to get it to within 1/2 degree of the spec'd 5 deg of advance.

It is a siamesed crossfire intake with a 1/2" lid spacer...and yes I'm checking EVERYTHING 3 times. :L

 

[LT4man]

Bill, any chance you could post a pic of your intake? I just cannot seem to visualize it in my mind.

Thanks a bunch!

Gregory

SAVE THE

 

[geekinavette]

Greg, I'm assuming you mean of the siamesed runners?

 

[LT4man]

Yes. Those are pretty trick. Did you port it yourself? How many HP does it add?

SAVE THE

 

[geekinavette]

My boss did it on his Bridgeport. That by itself won't add much of anything...I did that in combination with opening up the TBs, a little larger cam (but was still a fairly mild flat cam), long tube headers, and the 1/2" lid spacer. I never dyno'd it, but 0-60 dropped by almost 2 seconds.

I can't wait to see what the Edelbrock cam/head combo is gonna do!

 

[Yoda]

Bill,

uh, um... torq and C4 frames ??? or would that be skeleton ALL that new found HP "what cha go'n do with body alignment" :eek ...

Just thought I'd ask

Bud

 

[geekinavette]

Greetings Master Yoda!

The solution: keep the roof on! :L

 

[82ColEd]

Sounds very much like the X-Ram, Bill. Is that were you're going with it ? Openeing up the TBs, the runners..

Their website (LINKY) has some HP figures on them.. Friend of mine with a 82CE did this and ran over 265 kmh, he left some Euro Guys, that shut down at 250 kmh, standing with the old clonker :L but shut it down after reaching 270. hnoes

Whats the difference what you are building, as to the XRam "bolt on"?


-Stefan

 

[geekinavette]

Xram? Hell no...not even close. This is still a factory Crossfire manifold. The Xram is just a simple (tiny) open-plenum manifold with two throttle bodies on it...and a poorly designed one at that.

I'm not even going to attempt to do any comparisons to Xram...not worth it.

 

[KANE]

I still think an SY1 would look cool with the Xfire running gear. Would work well too.

I seriously debated going with that set up for on an '82 I looked at prior to settling on my '80. However, TPI was much more cost effective to piece together at the time. Plus, the '80 Vette had no electronics to throw away or otherwise remove. It was a super easy swap too.

The SY1 / Xfire lid would have proved more of a challenge than I had time for... especially when I had a newborn to take care of.

Anyways, another forum... lots of pics... and commentary... all about the Xfire and the SY1 intake.

http://www.digitalcorvettes.com/forums/showthread.php?t=2264

 

[geekinavette]

Well the project is getting close...after a few "snafu's" with valve springs and pushrods...it is almost all put back together. Right now I'm tweaking valve covers so the roller rockers won't bang into the oil baffles. I also got bushings for the throttle shafts installed (used machinable Teflon acquired from Ball Aerospace). I'm hoping to get it started this weekend.

Bill

 

[geekinavette]

I still think an SY1 would look cool with the Xfire running gear. Would work well too.

I seriously debated going with that set up for on an '82 I looked at prior to settling on my '80. However, TPI was much more cost effective to piece together at the time. Plus, the '80 Vette had no electronics to throw away or otherwise remove. It was a super easy swap too.

The SY1 / Xfire lid would have proved more of a challenge than I had time for... especially when I had a newborn to take care of.

Anyways, another forum... lots of pics... and commentary... all about the Xfire and the SY1 intake.

http://www.digitalcorvettes.com/forums/showthread.php?t=2264

Oh I'm sure the SY1 would work great with this setup...after tuning of course. Lots of fabrication work there. There was another crossram made a while back also...Edelbrock I think? I forget at the moment. Maybe someday when I have nothing better to do! :L

I am not at all a fan of the DC site...won't go there. Nor the CF site for that matter.

Bill

 

[geekinavette]

Well about time to update this...

The 'ol beasty IS back on the road. After lots of fuel line re-plumbing, add-on regulator, injector flow testing, and a LOT of tuning (which is nowhere near complete)...it is at least drivable! I still have a LOT of tuning to do (this GM ECM is such a piece of garbage) to get it anywhere near its potential...but it'll still hit 5grand in 1st gear purdy dang quick! (comparatively speaking of course). It makes CRAP for vacuum (still adding spark advance) and sounds like a damn stock car at idle , but coming along nicely.

Except for the fact that due to a miscalibrated alignment machine my tires are completely shot...so it'll sit until I can afford a decent set of tires. <pout>

 

[topless82vette]

why would you run 76cc heads or are you using domed pistons? With flat tops wouldn't that be about 8.5:1 compression or thereabouts?

 

[geekinavette]

Just depends on the height of the piston...the ones in there are 9.5:1 w/ 76cc heads.