20b In A Glc
02-29-2004, 06:33 PM
#793
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Join Date: Sep 2002
Location: Vanderhoof,BC(Canada)
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Originally Posted by Jeff20B' date='Feb 29 2004, 12:06 PM
I get to start test fitting the radiator today. 
02-29-2004, 08:21 PM
#794
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Join Date: Nov 2001
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Wow! That's great when stuff from different worlds just sorta works together.
Now I think I know where and how much to trim from the stock radiator area on the GLC. I'd like to get the rad in place before I pull the 20B. just to make sure the fan will clear it. I may need to trim the automatic tranny cooler lines from the lower tank (wouldn't be the first time).
Now I think I know where and how much to trim from the stock radiator area on the GLC. I'd like to get the rad in place before I pull the 20B. just to make sure the fan will clear it. I may need to trim the automatic tranny cooler lines from the lower tank (wouldn't be the first time).
03-18-2004, 10:12 PM
#797
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The 13B is almost ready to install. I've just gotta double check it to make sure everything is done before I remove it from the engine stand. Then I've gotta make room to set it on the floor while I pull the 20B out and set it on the stand. I'm always having to move things around.
03-19-2004, 03:48 AM
#798
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Hey Mike, you know how your 20B FC actually lost weight with your 20B swap compared to the stock weight of a car in your particular year and options package? Well, I was just thinking my car might break even. Going from 13B to 20B, of course (the piston engine was rather small and probably lighter than a rotary).
Let's compare the weight of the 13B that will spend a short amount of time in the car vs a stripped 20B. First I'll list all the relevant heavy items on the 13B. Then I'll try to compare them to the 20B. Let's see what we can come up with.
The 13B has '74-'78 rotors, which are the heaviest 13B rotors Mazda ever made for a production engine. REPU flywheel which is supposedly 33LBS, which is the heaviest flywheel Mazda etc. R5 side plates were not the heaviest, but not the lightest; I think the intermediate was thicker than earlier ones (it seems heavier than my '73 and '74 plates). '74-'75 rotor housings. Early internal reg alt 50 amp is heavier than later FB and FC alts. Cast iron waterpump with stock cast iron impeller and housing (aftermarket tend to be aluminum with cookie-cutter stamped steel impellers). Possibly JDM Hitachi carb with cast iorn base plate (heavier than a Holley). Stock '74 intake manifold with a 1/2" or so thick mild steel ACV blockoff plate which adds unecessary weight (I'll replace it with a thinner aluminum one some day). Lastly, it'll have a GSL-SE cast iron exhaust manifold which weighs as much as my 20B header, yet is concentrated right at the engine. The battery is also staying up front for the duration of the 13B install too.
This 13B is typical REPU flavor, which is good because that's where it'll be going as soon as I'm done with it here, but it's a little heavier than what would be a good choice for the GLC as far as power to weight is concerned. Sure it could shed several pounds with lighter components, but only a light flywheel would make the engine *feel* more powerful, while reducing engine weight some. What to do? Install a supercharger on the 13B? Maybe in the REPU, but not in the GLC (the shock tower is in the way!).
Let's compare all that to the 20B. No stock twins, light steel flywheel with a 225mm disk and pressure plate, only one more rotor housing, rotor (lightest 13B until the Renesis), 80mm intermediate plate of unknown weight with a stationary gear, a 16cm length of E shaft with one rotor journal, 16cm of 17 or 18 tension bolts, and two extra runner castings on the intake manifolds (four, actually). Even the header's weight is spread over a longer area and further rearward. I'll also move the battery to the back. Even though that's not technically weight reduction, it's a reduction under the hood, where it's needed most.
I still have plans to use the dellorto untill I can afford something better (FI?). Also the cooling system will remain unchanged for both engines (no need to upgrade when these same components adequately cool a supercharged 13B).
So what do you guys think? Do you think the heavy 13B will give me an idea of how the car will handle with a 20B in it? I'm curious how the ride height and ride quality will be. I'll probably need to get some RX-7 springs and spacer them up or something.
Let's compare the weight of the 13B that will spend a short amount of time in the car vs a stripped 20B. First I'll list all the relevant heavy items on the 13B. Then I'll try to compare them to the 20B. Let's see what we can come up with.
The 13B has '74-'78 rotors, which are the heaviest 13B rotors Mazda ever made for a production engine. REPU flywheel which is supposedly 33LBS, which is the heaviest flywheel Mazda etc. R5 side plates were not the heaviest, but not the lightest; I think the intermediate was thicker than earlier ones (it seems heavier than my '73 and '74 plates). '74-'75 rotor housings. Early internal reg alt 50 amp is heavier than later FB and FC alts. Cast iron waterpump with stock cast iron impeller and housing (aftermarket tend to be aluminum with cookie-cutter stamped steel impellers). Possibly JDM Hitachi carb with cast iorn base plate (heavier than a Holley). Stock '74 intake manifold with a 1/2" or so thick mild steel ACV blockoff plate which adds unecessary weight (I'll replace it with a thinner aluminum one some day). Lastly, it'll have a GSL-SE cast iron exhaust manifold which weighs as much as my 20B header, yet is concentrated right at the engine. The battery is also staying up front for the duration of the 13B install too.
This 13B is typical REPU flavor, which is good because that's where it'll be going as soon as I'm done with it here, but it's a little heavier than what would be a good choice for the GLC as far as power to weight is concerned. Sure it could shed several pounds with lighter components, but only a light flywheel would make the engine *feel* more powerful, while reducing engine weight some. What to do? Install a supercharger on the 13B? Maybe in the REPU, but not in the GLC (the shock tower is in the way!).
Let's compare all that to the 20B. No stock twins, light steel flywheel with a 225mm disk and pressure plate, only one more rotor housing, rotor (lightest 13B until the Renesis), 80mm intermediate plate of unknown weight with a stationary gear, a 16cm length of E shaft with one rotor journal, 16cm of 17 or 18 tension bolts, and two extra runner castings on the intake manifolds (four, actually). Even the header's weight is spread over a longer area and further rearward. I'll also move the battery to the back. Even though that's not technically weight reduction, it's a reduction under the hood, where it's needed most.
I still have plans to use the dellorto untill I can afford something better (FI?). Also the cooling system will remain unchanged for both engines (no need to upgrade when these same components adequately cool a supercharged 13B).
So what do you guys think? Do you think the heavy 13B will give me an idea of how the car will handle with a 20B in it? I'm curious how the ride height and ride quality will be. I'll probably need to get some RX-7 springs and spacer them up or something.
03-19-2004, 08:23 AM
#800
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Join Date: Sep 2002
Location: Vanderhoof,BC(Canada)
Posts: 5,542
Originally Posted by Jeff20B' date='Mar 19 2004, 02:05 AM
I forgot to mention the FC S4 NA waterpump and the FB 55amp alt. Both save a few pounds at the front of the 20B. I think they're both lighter than stock JC stuff too.