Little Engine, Little Tires, Little Nitrous...

[Barry Donovan]

Re: V8 powered RX-7 w/ engine setback

awesome work.

the original strut rods were modified from biscuit bushings to rod-ends for more front end travel.

I recognized the front end, strut bars etc.. relating to an 87 subaru (same japanese time frame)

I am inspired to do the solid rod end, just urethane washer. the biscuits arenlt exactly precise, munches on stuff..

love the build. I have been poondering a 400ci my bro-n-law has sitting around in the crazy welded subaru wagon.

these 80s j-tinners are similar to the vega...with unique traits. Intersting about the rx-7 tunnel being unusually tall. The subaru is unusual for the tranny and way engine sits in the bay (I would plop a big block right in on oem springs). kinda funny.. ;)

[weedburner]

Re: V8 powered RX-7 w/ engine setback

Thought i would update everyone on my bellhousing project for the car.

Basically, I am building my own bellhousing to adapt a Ford Toploader 4spd transmission to my old school SB Chev V8. I can buy one for around $450, but it's a heavy 1/4" thick steel monster, and I prefer building my own lighter parts if i can. I'm not concerned about it not being "SFI certified", as it's just a fun street car and i have no desire to make it legal for the track.

The mock-up began with an old 400 block and an empty transmission case. I am using the alignment bar from my rearend narrowing jig to keep everything straight and true. I spent a couple nights machining some steel pucks to fit in the block's main bearing bores and also the bearing bores in the transmission case. The pucks have an 1.501" hole in the center so that my alignment bar will slide inside everything to keep the engine and transmission bores concentric. I made a ring to center the plate that the transmission will bolt to, and a tube spacer that will set the desired distance between the block and transmission face. I have also made the rear plate that the transmission will bolt to, and have laid out the the flange that will bolt to the block and serve as a pattern for the block plate that will fit behind the flywheel.

I'll snap some pictures in the next day or so. Working in my spare time after hours, I expect it will take me a week or two to get it done. The transmission is getting some special work as well, getting faceplated in 2nd, 3rd, and 4th. I'm adapting an aluminum tailhousing from an SROD overdrive trans to replace the Toploader's stock iron piece to shed some weight. Also machined down the Ford throwout collar so that I can use my existing Chevy hyd throwout bearing.

Here's the pattern I made out of 1/4" steel. All the hole locations were laid out, centerpunched, and drilled 3/16" so that the pattern could be transferred to the blank piece of 1/8" that it's laying on, which will be used to make the block protection plate. The steel pucks on the right are the pilot rings and spacer that i mentioned in an earlier post that locate everything in the correct positions for mock-up...



Here's the drawing i used to layout the block bolt pattern...



This is the block plate after it was cut out and drilled. The large hole in the center is for the crank's flywheel flange to stick thru, and the 2 larger holes on the sides are for the locating dowels in the block...



This is the pattern after i drilled it out and cut the center out. It is going to be the forward flange of the bellhousing that bolts to the block, the large hole in the center is necessary to clear the flywheel...



Here's the block plate on a block. The upper "wings" were added as mid-mounting points that will hang the back of the engine at the firewall...



Here's the block plate and flange on a block. The block plate will be sandwiched between the block and bellhousing as shown. I'll soon be creating a hole and pocket for the starter.



The mid-mounts incorporated into the block plate allow me to easily remove the bellhousing/clutch/flywheel from the car without needing to support the engine. Greatly simplifies my clutch and transmission maintenance.

I'll post updates as i make progress...

[Darren N.]

Re: Little Engine, Little Tires, Little Nitrous...

Wow, that is some niiiiice work.

This has to be one of my favourite builds on the forum. I love how you've got a Mazda with a SBC, GM diff and it's soon to be sporting a Ford trans. Now that's hot rodding! 8)

Also, I have to say that the build quality of you car is pretty damn awesome. Your attention to detail is obvious in all the parts you've made and the fit and finish. I'm seriously envious of your fab skills!

[weedburner]

Re: Little Engine, Little Tires, Little Nitrous...

Thanks, Darren.

Here's a few more pics i had floating around that never made it to this thread...

The car uses an RX-7 alternator, mounted below the motor plate.



I changed to a really tall Strip Dominator intake with a 1/2" plate under the carb...the custom made air cleaner base drops the entire aircleaner 3" and almost completely hides the changes. Basically, it keeps the air cleaner at the same height as it was with the low manifold and no plate. It's pretty tough to tell which carb i'm running...my big Holley fits under there, but so does my little carb w/ the tucked in solenoids. The air cleaner and breathers actually have a little Skagit Speedway clay in them as they also did duty on my last Dirt Latemodel. I don't plan on cleaning them ever, just maybe blow them out and re-oil them once in a while...



I really like playing the underdog with the little 625cfm Carter. Nobody thinks you're serious when you tell them that's what you have. The little solenoids for the 175 shot are mounted directly to the plate and are completely hidden below the dropped air cleaner base. Holley jets (68n, 65f) are pressed into the brass nipples between the solenoids and plate. No way to get them in that close w/ a Holley...



You can also see my homemade thermostat housing. Needed something low enough to fit under the crossover tube w/o crimping the rad hose. The throttle cable bracket also had to be modified (lowered) so that the cable could come in under the extremely low air cleaner base. The little 357 has a 268/275 .657" lift solid roller in it, makes for a lot of fun in a 2325lb car! (well, 2525lb w/ me in it).

To be continued...

[glockster]

Re: Little Engine, Little Tires, Little Nitrous...


Incredible work. Wow that's just all I can say. Looks like this thing would be a hoot to drive

[BangShift McT]

Re: Little Engine, Little Tires, Little Nitrous...

That thing is effin' insane. Need footage, NOW.

[weedburner]

Re: Little Engine, Little Tires, Little Nitrous...

I welded the rolled ring to the bell flange today, all the holes still line up...



When i made the parts, all the holes were drilled to the same size as the bolts that go thru them. My thinking was that it would keep everything as precision as possible during fab. After i'm done with all the welding, i'll drill them out one size over to allow easier/quicker assembly, maybe 2 sizes over if i decide to powdercoat it.

[milner351]

Re: Little Engine, Little Tires, Little Nitrous...

Great work - can you show us more about how you made the drop base for the aircleaner?

How about some shots of your shop?

I'm interested in you're equipment / tool arsenal which helps you make these amazing parts!

[weedburner]

Re: Little Engine, Little Tires, Little Nitrous...

Believe me, the shop's nothing fancy. The parts were cut out by hand w/ a plasma cutter (a little Hypertherm 350, 1/4" max cap), using a flat magnetic toolholder (like you would hang screwdrivers /pliers from a workbench with) as a straightedge for the straight cuts, and i held a big washer in place as a guide to cut the scallops one at a time on the bellflange. The big hole was cut by hand by just following the scribed line that i drew w/ a homemade scribe tool that looks like a set of trammel points. All the welds are w/ my old trusty Miller MIG, CO2 and .035. I do have a lathe, a really old 16x50 South Bend flat belt line drive unit that's been converted to electric by someone a long time ago using a 4spd topshift gearbox from who knows what. I know i described the ring as a "rolled ring", but it was actually formed by running a strip of metal 3" wide by 40" long thru my homemade brake several times, incrementally making what was likely a few hundred bends look like they were rolled. I was going to make a roller years ago, i still have all the bushings/gears/etc, but just never got around to it.

The air cleaner base was made the same way, starting w/ just a cheap $20 14" air cleaner from Summit. I trimmed off the flange on which the element sits by hand with my plasma cutter. I then "rolled" a 3" wide strip of 18gua steel into a ring by bending it by hand around a large piece of pipe. I then welded that together to form a hoop, then used that to drop the base. I did change the wire in the MIG to .023 as the material that the air cleaner was made from was pretty thin. Clamped the base ring to a flat tabletop and started tacking everything together. After everything was tacked together with about 1" between tacks, i welded it up in short 1sec manually pulsed bursts. I could have oxy/acty welded it w/ a 000 tip like i do my oil pans for a little weld that looks like a TIG, but the MIG was just way faster so i didn't have to worry about warping as much.

[milner351]

Re: Little Engine, Little Tires, Little Nitrous...

Sweet! The plasma cutter certainly opens a lot of doors for projects.

Great work, this whole thing is out of the box, and off the hook!

[weedburner]

Re: Little Engine, Little Tires, Little Nitrous...



Here's a few more.

Here's the alignment bar in place in the block, as well as the spacer that sets the depth between the block and trans case...



Here's the trans case in position located by the pilot rings...

[Ron Ward]

Re: Little Engine, Little Tires, Little Nitrous...

I have always considered myself handy with tools, but man... you have MAD fabricating skills. Nice work.


Ron

[SuperBuickGuy]

Re: Little Engine, Little Tires, Little Nitrous...

that is patience... nice work.

[cantvalve16]

Re: Little Engine, Little Tires, Little Nitrous...

So, about that Carter carb... on motor, what do you think of it? What mods have you done other than pulling the choke flap? Tell us about it. Lots of us have Carter/Edelbrock carbs and could definitely use some tech on them. Pretty please.

[weedburner]

Re: Little Engine, Little Tires, Little Nitrous...

So, about that Carter carb... on motor, what do you think of it? What mods have you done other than pulling the choke flap? Tell us about it. Lots of us have Carter/Edelbrock carbs and could definitely use some tech on them. Pretty please.

I started using the carb back before the engine setback, when it was important for the engine to be able to launch from down around 1500rpm for "unprepped" tracks. The Carter pulled smooth all the way thru w/o any traction killing power surges (the car also had a Performer RPM back then too). Since it's a street car, being able to quickly and easily switch the metering rods without making a mess was really nice too. It did have a problem due to it's small size that i would get enough vacuum on the top end for the carb to go into cruise mode and lean out, but playing with the step-up springs cured that. I carry a little box in the car with a few different carb tuneups all organized in little ziploc bags, each with a little card that lists it's purpose and the specs on the rods/jets/springs that should be in the bag. This allows me to have my highway tune to squeeze a few mpgs from it and to keep my plugs clean idling around town, When i get to a test-n-tune or grudge nite, i'll get on my phone and pull up the local weather and do a little D/A calculation in my head and change the carb to whatever tune i feel it needs. The car also has a retard box in it for the n2o as well as a switch to control the retard function so that i can use the retard w/o the juice around town to kill any embarrassing bucking or surging that might occur when you combine a big cam, manual trans, and low engine speed (the extra lash from the faceplated trans doesn't help that either).

On the outside of the carb i removed the choke just to get rid of that extended electric choke motor so that i could use a dropped base aircleaner. I also removed most of the vacuum ports on the carb because they were capped anyway, and the little rubber caps always seemed to be cracking and leaking. I pulled the little pipes out and replaced them w/ machined aluminum plugs that i loctited and tapped into place. Bigger needle/seat along w/ due attention to float level and fuel pressure sum up the changes. I did build a few plates into the aircleaner base that key into the top of the carb that also might serve to funnel air over the choke horn and clean up the air entry a little.

I keep the Carter on now even tho the car has outgrown it because it's so easy to work with. It's lack of airflow becomes pretty much irrelevant when the juice comes on ;). I've got a few Holleys around, but when you show up at a grudge nite and tell 'em it's a V8 swapped car w/ a 4spd/solid cam/hi-rise/625 Carter it all sounds kind of : and seems to make it easier to find a sucker.