I am looking at rebuilding the entire upper end of my engine. While at it I figured I might as well put a larger cam into it. I know Fast Freddy's makes a cam, does anyone else? The freddy's cam has .420 lift and two different options of duration 260 and 272. Has anybody played with the cams much? I was curious to know how much this effects low and high end, and how much it will change the idle. Also I've been trying to find some performance Rocker Arms and Lifters. Haven't had any luck finding rocker arms that will swap other than 626. I was looking more along the line of rollers, but havn't had any luck. So I am contemplating whether I should keep the stock hydrolic lifters or convert to the lash adjust. The lash adjust allows much better tuning and experimenting with the valve train, but requires more maintainance and is a bit rougher on the entire valve train. The hydrolics are not adjustable but take a lot of harsh impact out of the system. Just looking for some input from ppl who have played with this.

The cam that fast freddy's is selling is the webber cam. you can buy it from them I'm not sure if web cams makes a copy. I have the higher weber cam, I did loose some low end torque I did gain a lot in the upper end tho. but you needa a lot to take advantage of this, I didnt really notice a big difference until I let it breath better. As for the rockers, your going to have hydraulic no matter what, unless you are nutz and want to try rollering it, but for me its just not worth the crazyness and the fact that what we have is bomb proof. You can use the arms off of the 626 to gain adjustability which is what you will need if you get the cam. Hope this helps out a little .. I might get the lower profiled cam if I was going to do it again.. but then again.. the look some guy gives u when you can rev match his civic is kinda funny.

I know nothing about the particular cams you mention, but every change in profile will affect engine performance in one way or another. Stock profiles are a compromise selected by the manufacturer to best meet general driving requirements for the vehicle. For basic aftermarket, you can aim for low end grunt, mid range acceleration, or high end horsepower. Engine bore, stoke, and transmission and axle ratios all enter into the selection process.

The thing to do is talk to an engine tuner and explain exactly what you'd like to accomplish. He can explain the pros and cons of the various combinations. Many shops will custom grind a cam, using your old one or starting with a fresh blank. This kind of work can get very pricy, but has to be weighed against the costs of random experimentation.


Hydraulic lifters are quiet but will often collapse under stress. This is why solid lifters are used in performance engines. Of course, with them you have to use very strong valve springs to prevent float at high rpms, and this in turn makes roller type cam followers desirable in order to reduce wear on the cam lobes. You'll also want higher oil pressure to handle increased lubrication requirements at high rpms, and better oil and filtration to further protect your investment.
The list goes one and on.


It shouldn't take much modifying to enable you to beat a stock B2200, but be prepared to spend BIG bucks if you want to run it on the strip.

hehe I'm running stock cam, carb, and except for running a collector pipe from the manifold to the cat stock exhaust. When I bought the motor it was scrap, it had sit for a year with antifreeze in the cylinders had badly pitted the cylinder walls deck and cylinder head mating surfaces. So when I rebuilt it I did some heavy machine work to it and opened it up quite a bit. Currently bored .040 over decked .005 and head shaved to maximum tolerance because it was heavily warped, I'm surprised the thing runs as well as it does. The pistons come slightly above the compressed gasket at TDC. I have moly rings in it with new pistons, don't know what the CR on the pistons are. I didn't know anything about Mazdas when I rebuilt it and didn't intend on making a hotrod out of it at the time. Otherwise I would have gone all or nothing and put forged rods and pistons in as well. Estimate CR to be about 11 : 1, runs like shit with anything less then 93 in it and runs even better with a gallon of denatured alcohol in the tank. Match ported intake and exhaust. I havn't come across a 4 cylinder yet that can beat me out of the whole, but once I start getting into high end, I'm smoked. I've even smoked a few small V6s. So I think I have plenty of torque to compromise to work on the high end. I know a bit what to expect when putting a cam into a V8 but have no clue as to how a 4 cylinder will react. Right now it feels like once I start getting into my power band I'm getting a lot of reversion into the intake and the acceleration just bombs out. I'm thinking its a combination of 3 things, First and most off my exhaust is way too restricted, second is too much exhaust overlap, and 3rd would be keeping the valves under control. The head is about to go out on my truck for good, so I have one I've rebuilt sitting here to drop in and I figure I might as well go all or nothing. Currently building 2 1/4" exhaust and adapting 4bbl carburator. I'm hoping once I get the exhaust on I'll know if it is a valvetrain problem or not. Considering the benifits of lash adjustors over hydrolic lifters, I think I'm going to convert over to lash, but am worried about how much worse the wear and tear will be. It would make sence that my lifters are collapsing, at low rev it runs smooth but once I romp on it the valves start clattering like hell. So considering how much torque I seem to have would you guys recommend the low or high duration weber cam?

You could phone fast-freddy's since they are the one's with the cam they'll be able to help you the most. And you'll need an entirely new intake manifold to do the 4bbl thing I'm sorry to say. It'll be great that your carb flows 700 cfm if your manifold only does 400. A big 2 bbl is more than enough for the motor, 4bbl will probably make you run worse since you'll be running so rich, but hey give it a try dont find out until you try. And as for the getting beat when we get going.. its our tranny man its just not meant for it, I'd like to see if the persons posting about the tranny can get the RX 7 one in there. That would make a big dif... up till 3rd gear we can go.. after that we dog.

I've already messaged Keir about this, and I might as will post what I said. I'm not just playing with one carb, I'm playing with about 4. I plan on modifying several intakes for both larger 2bbls and a few 4bbls. What I mainly have my eyes on is an RX-7 4bbl, its about the appropriate size for the motor and most of the sensors and vacuum crap can be blocked off and removed. I also have a 400 cfm Holley for the RX-7 as well I plan on playing with. If need be I'll build one to handle more air flow, I know a few engineering tricks to give an estimate on what will be too much and too little for the intake, as well as how to design one for torque and high end. As for high end power, the engine was never designed for high rev, the whole truck is built for torque. Has anybody ever noticed that the thing has a longer stroke than a Mopar small block? A lot of the high end speed is lost in the tranny and rear end. With how much torque the thing has I would go with swapping out an RX-7 5th gear, 4th is the same for just about all the manual trannys, set at 1 : 1. I'm out for the night.

I've already messaged Keir about this, and I might as will post what I said. I'm not just playing with one carb, I'm playing with about 4. I plan on modifying several intakes for both larger 2bbls and a few 4bbls. What I mainly have my eyes on is an RX-7 4bbl, its about the appropriate size for the motor and most of the sensors and vacuum crap can be blocked off and removed. I also have a 400 cfm Holley for the RX-7 as well I plan on playing with. If need be I'll build one to handle more air flow, I know a few engineering tricks to give an estimate on what will be too much and too little for the intake, as well as how to design one for torque and high end. As for high end power, the engine was never designed for high rev, the whole truck is built for torque. Has anybody ever noticed that the thing has a longer stroke than a Mopar small block? A lot of the high end speed is lost in the tranny and rear end. With how much torque the thing has I would go with swapping out an RX-7 5th gear, 4th is the same for just about all the manual trannys, set at 1 : 1. I'm out for the night.

You did'nt say if your truck was carb or EFI. I own a 92 that is efi. I am limited to the 260 duration, after talking to a rep at Fast Freddy's. With the intake that I am presently running and exhaust(header and two and half inch exhaust)the peak horsepower was raised by approx.. 25hp at 4700rpm.

My truck is carburated, I plan on eventually building a new intake manifold for it designed to mate up to a 4bbl. If I'm right I should be able to oversize the runners a touch and that will add a little to the hp and more to the torque because it will cause a high pressure area at the intake ports. If I'm right the lower duration is better for torque and highter duration is for HP, there is a lot of playing you can do with it though. I don't know what the stock duration is but if its around typical manufacturing specs its prb around 230. Any of you guys with the cam, did you notice a big change in how it idled afterwards not to mention how it sounded? Before I do any of this though I need to open up my exhaust, it is pretty much stock, with EGR crap removed. I'm worried that if I open it up to 2 1/2" it will kill my torque which performance wise is about the only advantage the engine has. I'm thinking about running a 2 1/2" collector pipe tuning it, putting my high flow cat right behind that and from there running 2 1/4". But I have still not made up my mind yet and I'm still waiting on stuff to ship in before I start.

It idles a little on the rougher side, nothing too noticeable with our jelly like motor mounts, but you can notice a bit.. as for sound. That just puts a smile on your face, its louder, but in a I sound more like a tuned up 12v or 16v instead of an 8.. maybe this is because of my valves and springs and the grind I'm not sure. As for the exhuast.. 2.5 inch is ridiculous man, 2 inch will flow more than you'll ever need to get rid of, I went with 2.1/4 for mine and it gives it a nice tone, its not loud, its just nice. but you can tell when I step on it. Just remember if your going to do the cam you've gotta replace the stock valve springs, they die and they die quick.

How did the tranny swap work out Ky?

Well I wasn't exactly swaping, I was modifying. I havn't started yet because I've never done tranny work before so I've been waiting for my dad and I to have a weekend to tear into it. I would figured that dual valve springs would be plenty? Wouldn't tripples cause too much wear on the cam? I was just looking at the replacement head I have for it. When I had it machined all of the valves where scrapped, I just noticed that, that the guy I took it too opened up the valves free of charge. I havn't measered what they are but they're much bigger than the ones in my truck now. This might prove to be quite interesting. Being since I didn't know of this stuff when I initially built my engine, I'm thinking of going to the yard and grabbing another one to rebuild strictly for street race. I'll still be doing the tranny and carb mods and stuff, but I think I'll try to get the new block ready quick enough to drop my new head onto it. I have developed an interminted nock in my truck that has me worried. Its not a tick like a lifter or a valve, and it only does it every now and then. I've tried listening to the engine with my dads electronic stethascope and done the hole thing with holding a prybar up to your ear to hear how the engine is doing. I can't hear it in the engine anywhere. But if I get under the truck I can hear it in the exhaust, so its in the engine somewhere. I have a radicle idea I want some feedback on, well actually a few. First this new block I plan on picking up and rebuilding is out of a probe, I don't want to go through the hassle of converting to fuel injection. What I want to do is use the stock intake runners fill in the injector ports on the intake and head and make an adapter plate to run 4 single barrel carbs to it. The other is to make an intake for a small blower. Either of these would mainly be just to show off the concept, but I would really like to see what a blower would do to a 4 cylinder :-? So what kind of feedback to you guys have?

Ok I have the RX-7 tranny appart and plan on making the mod to the B2200 tranny next weekend. I have taken pictures of every step and any differences between the two trannies I have seen. I'm trying to count the gear ratios to verify what I'm doing but I keep getting odd ratios that cannot be right. Like when I counted 5th gear I got 31:15 which comes out to 2.066:1. I just counted the number of the teeth on the big gear and small gear and being since the small gear is on the output shaft I divided the big gear by the small gear. I even calculated it backwards, which gave me around .458:1. Anybody know what I'm missing? The idler gear indicates that it is an 85 model, but my friend tells me that the bell housing is a 2nd gen, and their is evidence that the internals my not be the original set.

http://members.aol.com/solomiata/MX5Engine.html

This is the opposite of what you are doing but look at the bottom of this link page. Hope it helps!

Actually that doesn't help at all. The Mazda interchage site that Randy Stocker has was the first site I found that had any useful info for hotrodding a mazda on it. I've been using information off of it for almost every mod I make in some form or another. I have been using the page you just linked for months and have been using it heavily to look for cars with the parts I'm looking for. According to what he has listed the green speedo gear says its an 84-85 tranny. And according to his table 1st-4th is the same as the B2200 tranny. 5th is the only gear that is different. I have the RX tranny appart and it looks like I should be able to just swap out 5th gear. If not I don't see any design flaws in the assembly itself except reverse gear. The fixed that with a plate to reinforce the pin. So if I have to I can do like the interchange guide says and swap the internals and just take the plate for reverse and put it in the new internals. My dad made his own mod for this with his diesel truck before we new anything about Mazdas. But like I said there is evidence that the tranny has been played with. The bell housing is the same one that is on my friends 2nd generation which is different from the 1st. If I could figure out how to count the teeth to posatively know what the internals are I could be sure of what I have. But all the gears when I count and divide them I get a ratio of anywhere between 1:1 to 2:1. I can't see what I'm missing, you have 2 gears it should be a simple thing, all I really need to know how to do is figure out how to get the gear ratios, because it is the only way to posativly know what I have.

(I even calculated it backwards, which gave me around .458:1. Anybody know what I'm missing)

I don't think your missing anything - Go back to that other link and look at the Transmission Ratio spread sheet. Your calculations look similar - NOT?????

Ok I think I see what I was missing, it was on the miata 5th gear interchange table. I need to count the input and output shaft splines divide them and multiply that ratio by the gear ratio and whala I should have the final gear ratio for the gears. Thanx dude.

Thanks for the info on the exhaust size Keir, I'm going to downsize and see what happens.