I'm trying to find out the intake port runner size of an XC-8 cross ram. Also is there any "meat" around the ports to gasket match to a Fel-Pro 1206 or even a 1207 gasket??? I'm trying to figure out the largest aftermarket head port and the largest cubic inch small block chevy I can bolt one on to and make decent power. No sense building a big inch SBC if you can only run a 180CC intake cylinder head. I'm building a street/strip Anglia g***er and am dead-set on running this intake even though I'm aware it has several shortcomings. Has anyone had first-hand experience running this intake on a high-horsepower street/strip engine. I've searched and read several posts about this intake on mild builds. I am not planning a mild build. Can anyone help a brother out?
I've seen a stroked 283 (5/8 arm), XC8 man with Isky 550 roller, Heads by Jocko etc etc turn an instant 9000 RPM. Heavy all steel 56 Chev run 12.00's at Lions. That was early 60's. 4 spd of course.
Although it's '60s design and technology a XC-8 worked well on my 327 powered '55 Chevy in the '65, '66, '67 drag era in So Cal. Stock short block, Mondello ported heads, a Chet Herbert roller, 4-speed, 5.57 rear gears. Carbs were 2 -500 cfm Holleys. Ran a best of 11.20 at Lions. Power shifting at 8500. Should still work well today. Sounds like a great ride you're putting together, good luck.
My plan is a vintage formula, 11 to 1 301, z-28 race cam, offy cross ram, 2 450 holleys, and some hogged out 2.02 camel humps I think it should go, they sure did in the day
Thanks for the input guys. I'm still looking for the actual port measurements if anyone has one of these sitting on the shelf. I'm thinking of a 400 plus C.I. chevy with a great set of modern aluminum heads (painted to hide them of co****) with a solid roller cam. The aluminum heads should allow about 11:1 compression on premium pump gas. A fully polished XC-8 with a set of Holleys and polished vintage valve covers will keep it looking age appropriate. The Anglia weighs 2,600 lbs and runs a turbo 400 with a 3500 stall converter. Ford 9' with ladder bars and coil overs. 3.89 gears. May go steeper on the gears 'cause the tire are 30" tall.
Now I'm curious..... Grab some calipers or a 6" scale and start checking the port sizes on both the head intake port an the port exit on the intake manifold... And post some pictures damn it!
Performance wise this setup was alot better than the factory 283 2 4bbl setup, however, the very first Edelbrock tunnel ram (TR-1) with is crude in design, still killed the XC-8 by 60+ HP! at peak rpm and was good for 1000+ rpm more as tested on a 331" Modified Production engine by Edelbrock in 1969. The performance potential of the XC-8 gets worse on bigger engines. A few years ago one of the FE Ford guru's tested every manifold he could get his hands on, on a 450ish HP mild 428. The Mickey Thompson and Edelbrock tunnel rams were the worst by 35+ HP. If you want great performance with two 4bbls, the Weiand and Edelbrock "Street Tunnel rams" as they call them today are the best ones. The edelbrock Pro Ram is too big for most combo's, however the Holley Pro Dominator tunnel ram is a good piece also.
Thanks Panneton Bros, That was the kind of information I was looking for. So much for havin' my cake and eating it too... I love the cross ram, but want to make some serious power. I can't run a dual-carb tunnel ram (I have a TR1x) as the engine is set back so far I would have to notch the cowl clear into the base of the windshield. I had thought of running a single carb tunnel ram, but like the look of the cross-ram so much more. I guess it's time to do a gut check and see what is more important to me. Having a period correct g***er with something different and cool under the hood, or running some better numbers at the track. Damn compromises!!!
Check out a single carb Weiand tunnel ram, the carb pad is higher than the two 4bbl top, but can easily be milled down. You can also remove about .375-.500 from the bottom of the top half and the top of the bottom half. I had to do this to get two carbs under my cowl, works fine. The Holley 950 3barrel came out in '68-'69 so you could use one of those for the erra correct deal. If your sold on a cross ram, look for an Edelbrock STR-10 with dual carbs inline or crossram, however, the Weiand tunnel ram is still 30-40hp and torque better everywhere. The Edelbrock and Weiand "street" tunnel rams are actually up 30+ lb. ft. of torque more than any single 4bbl 2 plane or single plane at rpm's below 3500 rpm! This is due to moderate plenum volume and long narrow runners. The engine in our '56 has early Edelbrock victor Jr's with some porting and the Weiand ports were a near perfect match with no sand rolling, in fact the only sand rolling needed was to "square up" the as cast ports of the manifold. A last option would be the old Offenhause two 4bbl inline "Hi Rise", and you could locate two of those crazy Offy carb spacers that swing the carbs to the side.
PS. Q-jets came out in '65, so.., I can do 750 or 800cfm version in single or dual quad configeration if you want something different.
PPS. The TR-1X you have, I believe has the second design plenum which is "rounded" and looks like a loaf of bread. The last design (you can buy this top from Edelbrock, Summit, Jegs, swapmeet etc.) is much shorter and makes more power anyway. This might allow you to use your existing bottom half with the later upper (it bolts right on) and possible use it after all. As a side note, the "late Edelbrock" is about .250 or so shorter than the Weiand. Don't be bummed about the "late" one as this version was sorted out by Grumpy Jenkins for his 331" Pro Stock Vega in '71.
Lots of guys turned their SBC engines really high back in the day and swore they pulled hard to 9000-10,000 rpm. The dyno thrash Edlebrock did back in the day showed the XC-8 to have fuel stand off above the carbs at the start of the pull 4500rpm. The xc-8 was done at 7000 and falling off HARD. The very first TR-1 tunnel ram (which again, is fairly crude in design, pulled strong to 8000 and was up 60+! HP. So lots of 265-350inch small blocks may have been buzzed to 9000+ with XC-8's, but they didn't make peak power anywhere near there.
Until recently the baddest "std. port location 23Deg." head for a small block chevy was AFR's 235-245cc versions, which flow in the 350cfm range..,killer, and cost $2350.00 set I believe. There is however a place out here in Anaheim called "Dr. J's Porting Service" (talk to Bryce). He can get similar cfm out of a Professional Products casting (made in China, so this is hard to swallow if your a patriot and I hope you all are). He told me he can sell these heads done and complete with steel hallow stem valves for $1500 set! He has made 800+ with a 427" small block on 1 4bbl with these.
On another thread I thought I saw fenton Gyros on your car. Those didnt appear until after tunnel rams hit the scene anyway, so I wouldn't lose sleep about the tunnel-ram not being "period correct', you are already into a early seventies build anyway. And Pannentons comments about the Edelbrock ram-log are dead on the money, a TR1Y or TR1YX will run away and hide from it. And if you plan to use a TR1Y on an engine that large, I would shorten and enlarge the runners to the limit of the casting. It was originally designed to make good power to 8k on early seventies 288/292 MP engines.
Thanks for all the info. Are you saying this top will fit on my base? Here is a pick of the intake I have. (this one is not mine).
Good to know. I'm not worried about the tunnel ram being period correct, I was worried about getting it to fit with out notching the cowl all the way to the windshield. With the shorter top, I may be able to make it work fitting it under the cowl. I would still have to notch it, but not as far back. The carb will sit under the cowl, but the air cleaner/scoop would protrude through the cowl. As long as I could leave 1.5 to 2 inches from the base of the windshield, I'm good.
A few years back, (ok, more than a few), we ran an XC-8 on a healthy SBC, running a VERY worked set of 882 heads, a big, fat dome on the pistons, and a Comp Magnum 305 cam. Dead simple setup, just something to have fun with. We ran a Vertex mag on it (just 'cuz), along with a set of vacuum secondary 600 cfm Holleys that I did a little work to. It was stuffed into a '71 El Camino with an 8" converter that stalled around 4800, a TH350, and a 12 bolt with 4.88s. The combination ran high 6's, low 7's in the 1/8, with a load of 110 fuel, and was an absolute BLAST on the street. Were we giving something up running the cross-ram? Definitly. The car actually picked up almost 2 tenths with a good single 4 bbl and single plane intake. But the fact is, it did work, fairly well. Pretty tough to beat the looks of the XC-8 under the hood. And yes, it fit under a stock hood. BARELY.
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