Edelbrock xc-8! tips and tricks to a crossram.

Well my father picked up a xc-8 at a swap meet in dallas tx last year for my birthday, lately ive been learning a lot that this old technology isn't that great, but i think it looks cool as hell, and im sure that someone has had a xc-8 running pretty good at one time. right now im in the process of building my budget 350, all i need is a gasket set and re-assemble it. but as soon as that is done, and during the summer when i get a job i want to start on a new engine for my 55 chevy, im looking to build this 400 4 bolt main i picked up from a 71 caprice 4 door, it had 30 some thousand original miles and everything is standard, my plan is to swap this stock pistons out for some aftermarket just something to raise compression up a little, get a set of world sportsman II heads, and run either this cam since i have it http://www.cranecams.com/product/cart.php?m=product_detail&p=23985
or get a custom grind solid roller, and i would really like to run that xc-8 on it, right now the intake is set up with two 550 holleys, i was wondering how good is this intake? how would it perform on this motor? I love the look and would like to use it, to make this 400 look like a nostalgic late 60's motor. Also any tips and ticks to running this intake would be very useful.

 

What gears are you running, what year of vette? Sounds exactly what I'm looking for, my car is going to be a 4 speed car, with 4.10's or 4.56's on a 30 inch tall hoosier quick time pro.

 

Bump!

 

do you have a pic of that crossram

 

I've got 3.73's in it now with a 27" tall tire. The car is a 64 and I plan to stick the 4.56 gears in it if I ever get around to it.

 

Yeah! What he said! ^^^

 

Put a 327 crank in the 400 if you want an engine that realy
like to rev (354 ci)short stroke big bore with god flow around
big valves. The combination chevy missed

 

But where would i find pistons?

 

O would i love to have a 64 vette!

 

and yes that is my room lol.

 

My only experience with an XC-8 was a friends engine that he built in the summer of '68. We had just graduated from High School and he worked at the local Chevron station. The engine was a two bolt 327 from a 63 wagon. He put a 5/8 stroker (welded/metal sprayed) with 12 and a half M/T forgings. The first set of D shaped Mondello small block heads I ever saw. At the time Chet Herbert was getting out of the small block cam biz and was going to concentrate on top fuel Chrysler cams so had a deal on the 524 lift 324 duration roller. I mean like 600 bucks for the cam and rollers and links. Yea that was a lot in '68 but still, that cam was like jewelry. He put it in a 62 Chevy II with a solid front axle and a 4:30 Olds rear.

My recollection is that engine didn't have the torque of a Mo-Ped below 3500 revs. But once you got past 3500-3700 you couldn't get your eyelids to close. The hardest accelerating un-blown car I have ever been in. maybe it was the cam or the overall combination but it seemed like it liked a lot of revs.

 

Dont remember where i bought them but there is pistons made for
this combination. Or was atleast 10-15 years ago
This is a combination much used in nascar

 

The speedway motors garage sale has a couple sets to put a 265 283 or 302 crank in a 400 block....


As for the original Q, ram tuning will tell us that a manifold like that only really likes to run a a certain high rpm, probably around 7,500, and also has a pretty good gain at about 1/2 that rpm.

Same rules apply as to tunnel ram, only difference is the runners are divided

 

I have a crossram I ran on my Dodge for years. The main tip I would give is watch out for backfires on starting. Wire the ignition switch separately from the starter so you can get it cranking for 2 sec or so before switching on the ignition, so the engine is already spinning and pulling some vacuum before lighting it, this will help prevent the big bang.

 

O

Sounds like a really cool engine, Whatever happend to it?

 

so they backfire alot?

 

Sounds like a really cool engine, Whatever happend to it?[/QUOTE]

It "done blowed up". Actually i went off to basic training a Lackland AFB but got a note from him. Think it sucked a valve and then bad things happened.

 

I ran an XC-8 on the street for years. I went through several carb changes and fouled many plugs with that intake. After finally figuring out what my combo liked it was a pretty good intake.

The few tips I would pass on:

Make sure your carbs are identical, not just part number but how they are tuned. You have to remember that one carb runs the opposite side 4 cylinders of the engine. Any differnce in throttle springs or linkage setup will make one side work different than the other. Back when I ran my setup you could still order linkage setups from Offenhauser. Their small block chevy cross ram intake is almost the same as an XC-8. Their linkage bolts to the XC-8 with no modifications.

Anothe tip (which isn't too traditional) is a mutiple spark ignition box like an MSD 6A series will help when you are running a little fat. My plug fouling days greatly diminished after installing that ignition box.


Have fun with it. I got a lot of looks on my '55 when people saw it on there. I still have my setup rotting on a shelf in my shop. Don't think I could ever part with it.


DuckusCrapus

 

Wouldn't an X-8 run alot like an X-1 intake? I haven't had any issues with backfires on the X-1 I am running.

It's interesting learning to listen to the left side of the exhaust to tinker with the right side carbs. Way different than the tri-power I had.

 

I forgot to mention....when I had mine I called and talked with Edelbrock about some history on the intake. The guy there told me that the XC-8 was the last intake that Edelbrock Sr. worked with.

Don't know if that is true, but kinda neat if it is.


DuckusCrapus

 

Don't know if it applies, but years ago, Hot Rod mag did a shoot-out with different manifolds. The one thing they noticed about the crossram was a reversion problem. At idle, the could see a mist above each carb. My buddy tried a crossram on a bbc. He even built anti-reversion dams to help with tuning. He eventually went with dual quads until he gets his Hilbourne injectors up and running.

 

What was your set up? motor wise?

 

Dual quads as in a tunnel ram set up?

 

SBC 350, Edelbrock Perfromer RPM camshaft, open chamber heads with 2.02's, and some crappy low compression pistons. My compression ratio was ballpark 8.5:1. Headers with 2.5" exhaust, and a TH350 with a 2700 stall.


DuckusCrapus

 

So it might run pretty decent on my 350? Stock flat tops, close chamber 2.02's comp 292 cam 4 spd

 

i got a 69 crossram z28 that i had since high school stick with chey parts they did tons of research for the trans am racing in the late sixties you cant beat the chevy off road cam #140 sounds like a monster sitting at idle just put the idle at 1800rpms i used to drive it everyday just run a decent gear 488 the motor dosent do anything till after 4grand

 

It's that there is a lot of plenum volume in a crossram so IF they backfire, it can be a lot bigger. Some folks add blow-off valves or burst panels to their expensive sheet metal racing crossrams to protect the manifold from damage. Mine is an old oem magnesium one and pretty valuable; I was warned that a lot of them were damaged from backfires over the years, so I was always very careful about the starting procedure...

I'll attach a pic of when it was on the car...

 

Damn looks sweet!!!

 

Another awesome set up, what are you running it on?