my rotary bug

[dubber91]

HEres my rotary bug. I can now honestly say i have done everything to this bug (or redone it anyways)....
The engine is a 13b NA 1988 RX7 engine. with hindsight i would probably have gone for a carbed engine (either a 12a or a 13 with a carb manifold) instead of the injection system. The only advantage is that you can fit the turbo'd engine eaiser once you've fathomed the electrics!

Cooling this beast is a 3 row rad, often used on v8s and the like. The coolant lines are stainless (with hindsight i would use copper or alloy for better heat dissappation), i use the stock water pump AND a VR6 electric water pump to help circulate the extra coolant pipe length. The rad is boxed in with stainless sheet. In these pics its a bit tatty.....just getting it running more than anything. I plan to run the induction system through the firewall and up to a window and re-fit the standard, uncut semi w decklid. I have disks on the front, and am currently making up some for the rear using rover vitesse calipers.

I use the stock 1300 box which, although isnt an ideal 1st/2nd gear change, its totally streetable. It is also 'close ratio' due to the higher revving rotary engine.





The engine fits in! must have a removeable decklid though




hope you like! PM/email me any questions you have!

Steve

[jp]

ride dude looks really well done. How many miles you done in it ? had many sorry any issues (so negative thinking that people always have issues)

Like the colour combo and the small cannon sticking out the deck lid
wahey never thought I'd get to use that smiley

Oh and welcome
_________________
1971 Devon Bay with 1800 Ford Turbo Diesel Engine (wip)
1983 VW Golf GTI Campaign
1979 Mini 1275 GT
2013 Scirocco TDI GT

[dubber91]

there ARE always issues.....mine have been based around the original plan. Mainly cooling, i must say, based around insufficient rad size. Rotaries require an oil cooler...the stock one is HUGE. Using it above the gearbox seems to do the job, but routing lines can be difficult.

I have had the engine out on numerous occasions now......Once a cooling hose split, and the original engine was rubbish (i have been told its likely to be an internal oil seal), and another time the flywheel oil seal went.

Getting a good quality engine, a rebuild is usually essential, can be difficult, as turbos seem to be rebuilt and are for sale much more often. You can buy a knackered rx7 on ebay for about £200 so keep an eye out

Electrics can be difficult, and the shear amount of vacuum hoses can be daunting, but largely, leave em where they are, and you'll be fine.
I cant say how many miles ive driven on this engine....i did a fair few on the old engine, even though the oil seal had gone from the start.

Plan is to take the engine apart, find out what was wrong, then rebuild it with a bridgeport. Bridgeporting does take away a little low end driveability, but its usually OK on the road.....with a little work it'll rev up to 12k aparently! higher than my tacho!
:smt010

[ricola]

Did removing the rad intake mesh sort your cooling?

Rich
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http://www.ricola.co.uk

[rjes]

Your RX7 conversion looks awesome. My uncle had an RX7 turbo - it was seriously fast. A bit of a tight fit to get the turbo in a beetle too though, I imagine! You may be interested to check this page http://www.rjes.com/html/material_choice.html . I recently added it to my site after reading some incorrect information on the subaruvanagon yahoo group about coolant pipe choices. Basically copper or stainless are not the best choices in terms of galvanic compatibility with an alloy engine (RX7 engines ate alloy, aren't they?).
Did you make your own adaptor, or buy one from somewhere?
_________________
Regards,

Richard,

R J Engineered Solutions
Quality Subaru Powered VW Components
www.rjes.com

[dubber91]

Galvanic corrosion is more likely to corrode the copper parts of the system. Likewise, copper will deposit upon alloy or steel before corroding it. Theres such a thing as cathodic protection......oil rigs use it. Often Zinc is added to the rig-legs....the zinc is anodic to the steel (and current flows from it to the steel). As the cathode, the zinc in solution may deposit as an oxide upon its surface......it may also just dissolve into the surrounding water.....but the end result is the same.....the steel's rate of corrosion is lowered.

Im more worried about the cooper parts of my system TBH. Ideally i would use galvanically identical materials....i.e. the same material as the engine block throughout....

[jjenibun]

Hey dubber I noticed that your exaust pipes, look almost as if it has a regular vw engine in it. Tell me a little bit about your setup.
Thanks. I have a 1969vw bug, I am in the process of removing the engine from a 1983 Mazda rx-7 as we speak. I have not yet decided what type of muffler would work. I have a single quietpack that was on my old 1776. Would that possible fit.

[dubber91]

12a (1st gen early mazdas) engines have a different exhaust flange to 13b's, but the principle is the same. Using the beefy flange present on the standard exhast, you can weld up any style of exhaust you want. As it happens i am not happy with mine. Rotaries work on exact backpressure, and exhaust temps can reach 2000 degrees farenheit! (due to the combustion of oil in the mix and rapid firing(three times per rev)). Therefore you should look for a muffler with ceramic filling......metallic based wadding will melt quickly. Some bike cans (mine for instance) has ceramic wadding, although the length of the exhaust is insufficient to dissapate the heat and bring noise down considerably. I have a plan for an exhaust to be swept back, over the driveshaft, over the gearbox, and exiting in front of the drivers side rear wheel. That way NO muffler will be seen from the back. I would suggest you DONT use the cheap quiet pack you mentioned....