Hey guys, I have been thinking about trying to use a BBC Mickey Thompson crossram on my old '55 chevy g***er. I know a single 4 will make loads more power, but straight axle '55s are common enough these days and everybody's either got tunnelrams or single 4's. The motor is a 12.5 to 1 454 with a solid flat tappet ZL1 cam and 074 ZL1 heads. It's a 4 gear car with 3.90s, it gets weekend time and is already wild. I just don't want to get the damn thing where it's too much of a ***** to drive anymore than it is, but that old crossram would be ***s if I could make it work. Anybody have experience with'em and what carbs would work best? Holley 450s? Edelbrock 500s?
You can make it work fine ! Just carb it for the cubic inch you are using. If you can handle it like it is now,,it will not be any worse to drive,,about the same at***ude wise. just drive the hell out of it ! With a 454 ,,I would go with 600 to 650 CFM ,,myself. Tommy
http://www.jalopyjournal.com/forum/showthread.php?t=520996&highlight=cross+ram http://www.jalopyjournal.com/forum/showthread.php?t=142937&highlight=cross+ram Found this in minute on the 'search' feature.
Oh I'm sure someone's going to disagree but....... For looks I say go for it, but for performance fuhgeddaboudit! Even the '69 Z-28 crossram was designed for high revving Trans Am racing and it still didn't work right.
I had read alot of threads that say you can't tune it, it won't work, use a single 4 instead, etc, etc, just seeing if anyone had any practical real time experience with one and if it was do-able on a borderline street car.
There are a lot of guys that swear solid lift is no good too. What do you think? If you can handle it with 12.5 comp. and what it has now for a cam and gears,,Go For It !!! Message me if you need advice. Tommy
I had an Offy cross ram on a 30 rpu, drove it damn near everyday. It had 2 600cfm Holleys on it (I now a lot of carb for it) but it drove great, good throttle response. There are a few pics of it on redneck rumble thread on here somewhere. 2011 I believe. No pics on my phone or I would post a few. I could email a video of it running down the road if interested.
Ran the same setup, same heads, but with different gears, a roller cam and T-400! Same C.R. Chevelle, '66, total "streeter", NY registered and inspected. Never had a single issue with the cross-ram, only item I didn't care for was the fact you can't fit the "tall" style valve covers. Not enough room between the manifold sides, used "short" covers. I worked with some aftermarket linkage and a made a few of my own mods to "connect" the linkage and avoid "slipping" on the shafts (visible in the shots below). Thanks, Gary in N.Y. P.S. Here's 2 shots of the setup, I still have it here but the ride's long gone! That's a pair of 650 Holley double-pumpers! Simple to tune also!
My thoughts: You already have the intake..I would do 600cfm 4160's with 3310 [re: old 780] bowls and metering blocks, rear blocks pwr valve plugged and jetted up from front by ten sizes, front metering block pwr valve sized according to engine vacuum at idle..I know a lot of work [to put it mildly] and just a starting point! If you feel like spending some time sorting it out go for it...
Like that linkage pic GOFAST. That was another issue I was going to have to figure out. Thanks for the info so far guys.
A lot of years ago, one of the magazines did an intake manifold shootout. One of the worst manifolds was the crossram. It had a problem with reversion, so much so, you could see a vapor cloud over the carbs. They tried anti-reversion dams which helped make it more drivable, but they finally gave up. Fast forward to a few years ago, my buddy built a '34 Ford Coupe with a 427, a big cam and a crossram. I gave him the aforementioned advise but he still fiddled with it. He tried the anti-reversion dams to no avail. He finally switched to dual quads and was much happier.
One thing I have found out about the M/T crossram is that it has a crossover between the plenums that is supposed to be alot better than the edelbrock one, supposedly. I have 0 experience with 'em
Ran one on a 355 smallblock in my Nova back in the early 70's, drove it to work everyday. Two 660 center squirters never had a problem,except that every time I jumped on it I watched the tack go up and the gas gauge go down almost as fast as the tack was going up.As stated above today if I were going to race it would be one four barrel ,but for coolness go for it.I lent one of my big blocks to a friend for his 55 g***er, and he is going to run either a crossram or tunnel ram with two fours on it.
I had both a Mt cross ram and edelbrock shoebox on my 56 chevy in the late 70s with a 327 4 speed, 5.38 rear. Both setups ran 12.0 in the quarter. My instinct felt the tunnel ram was slightly better, but you can't argue with actual data. Nothing looks better than an MT cross ram, if you can handle the extra weight of that monster. Enjoy it and try it!
I say run it... its different and looks killer, and yeah tuning is a bit of an issue but once right it will deff put some power down and do it well...
Let me clear up a myth here unless you are running a single dominator a single 4 is not going to make more power than the cross ram. A single 4 is easier to tune. If you are willing to tune or learn to if you are not a tuner you can squeeze as much if not more power out of your cross ram over a given RPm range. The characteristics of the intake are going to be different than your single 4 setup. If you are running a 360 drgree intake on your single 4 then your RPM range with the cross ram may be close to the same. There is a trick that we have used to make them easier to tune, run ballance tubes from one carb to the other. it can be done with a large va***um line from the base of one carb to the base of the other. I would not run an M/T cross ram or any cross ram for that matter for looks but if you are really set on making it perform and perform well then it is a good idea.
There are valid reasons why cross ram manifolds were replaced by other alternatives. Although the cross ram doesn't ****, later single plenum and tunnel ram manifolds addressed shortcomings that cross ram manifolds had. If you were using port fuel injection I would feel better about using one, but that's not what you want to do.
Most of the M/T cross ram or ram log intakes had a crossover cast into them, so it's most likely going to be the easiest to tune of all those style intakes.
Im a fan of crossrams and have 2 I plan to run its the look im after... and its the lowest cost way to get that look. To me A street g***er style car needs something more than a single carb sitting there. I say make it happen
I have run crossrams and other dual carb setups at the track and on the street..Have two currently on AMC engines..One setup uses 450 holleys and the other 500 Edelbrocks..Both work great on these engines (390 CID).Depending on the cubic inch you're using,you may go up to the 600 cfm Edelbrocks..Smaller carbs will be alot more responsive on the street,but the big ones will have better track performance.I have run dual 700 and 750 Holleys for the track and they work great too once you dial them in..Crossrams have a bad reputation for being soggy down low and puddling fuel,etc. but with the right carb setups these things run great and look KILLER too!..Don't be afraid to run it!!
Here is my setup- even though there are a number of not so efficient parts and pieces on this motor (the mag @ low rpm, the scoops, the intake, etc...) it will blow the Hursts clean off my fake 27. I mean clean off. You want 50cc Accelerator Pumps: Dve
As I and others have mentioned, it's hard to get any cooler "looking" than this! ^ ^ ^ Looks good Dve
I ran an Edelbrock on a 427 Ford in a '69 Mach1 for a while, and it just takes a few things to make it work. BTW, the Edelbrocks have always seemed to be the better runners, the M/T's seem to be better at looking good than running good. You setup should actually work pretty well, they like some squeeze and some stick. Mine was about 14:1 with a 324/590 Sig Erson and two 650 DP's with just a couple sizes up on the primaries and 3.5 PV's to match the cam- don't get talked into removing the PV's, always a bad idea on a street car- just size them right so they work for you, not against you- just part of the tuning. Making sure your carbs are exactly matched and the linkage is precisely adjusted is half the battle, and mine was sensitive to ignition timing- just a couple degrees short, and it would stand off and blow gas out of the carbs something fierce, but bump it just a few degrees and it came to life and was VERY responsive. I ran it with 4.86's and a set of 12.55 Blue Streaks, and it would instantly blow off the tires from a 35 mph roll in 3rd. Really strong from about 3500 to 7300,and then faded fast Took a couple confirmed Chebbielovers for a ride and they were "converted"
- Cross rams have quite a bit of plenum volume, so throttle response on the street IS lazy compared to many of the alternatives. That also means they need a lot of accelerator pump. - The race-type cross rams we are talking about have fuel distribution issues that are worse than the better of the manifolds that replaced them. That also means jetting needs to be on the rich side to avoid lean cylinders. - A big problem with these manifolds is that many don't understand carb sizing and use carbs that are too big for the engine. - The manifolds don't have heat. That is good for racing, but can cause driveability problems under some conditions on a street engine. Having a lot of unheated surface area also makes them temperamental when the engine is cold. None of this is saying that cross rams won't work, or won't work on the street. Just understand and be willing to live with the nature of what you are working with.
I'm currently running a MT crossram on the FE in my 31 with two 600 Holleys. It starts great, cold or hot, and runs great too, with no bogs or hesitations. My only complaint is I can't get the idle below about 1000 RPM. The car is light with a 5 speed and 3:55 gears. I read the "Intake Comparison" article on the FE forum and without doubt, there are better intakes for racing purposes, but the crossrams are hard to beat in the eye candy department.
I think I am about sold on trying it out. My car is driven only to mess around on the weekends, have fun with and I will be making some p***es in it at HRR in Bowling Green. I am finishing up my straight axle install and will post up all the pictures when I get it finished in a few weeks, then I will let everyone know how the crossram turns out. This car is just for being loud and overpowered and fun to have, so I ain't really afraid of trying the crossram out.
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