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How To Build A Rally Car


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Well, another fortnight of holidays has slipped past and not enough got done!


I picked up the 18RG bits from the engineer on the way up to Walcha so we had all the bottom end balanced, and we ended up concentrating on assembling that. Its the first of 4 or 5 motors Steve had bought for the Celica and we need to get them running in an RA40 one by one and sell them off. That's the motor for his road Corona Grumpy, the one from Speedhunters, and he'll have to update that build thread.


Little bro Richo and I put his 345K together and that is now running, quite a little monster with a 4K block, 5K pistons, a 3K head and a wild cam. He spent a day or two getting the best setup for the Weber DCOE he has and once it is run in I expect to see some neat graphs off a dyno app he d'loaded. It just walked away from my stock KE70 and sounded like a 13B when crawling along in 1st gear. The build thread he has for it will be updated.


I'll download my camera tomorrow and update this thread too.

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Ok, the first job was to move the rally car, so it needed the Bilstein front struts from the RA 40. First problem was that the nicely cleaned and painted KE70 steering arms just didn't quite fit the RA40 struts, so after a lot of pissing about we raided the wreck and cleaned up the RA40 arms.


With them in place we found the 3 turret holes on a KE70 have a unique pattern that nothing else will fit, so new cross-strut bar ends and new camber-tops would be needed on the RA40 struts. Then we found that even with the stock KE70 strut top the RA40 spring top wouldn't fit in the turret, so we moved further down and used a stock KE70 spring top, which meant a KE70 spring.. This meant we could push the car out even if those springs will not be any good for rallying.


The photo has the KK70 spring gear on the RA40 strut that we moved the spring perch up on last year.



Steve wanted to build the 18RG motor for Grumpy as we had all the bits for that but didn't have the roll cage tube yet. We got started and of course the tube arrived, but he was dead set on bulding the motor rather than the cage.. "It will only take a couple of days..." First was to free up an engine stand that had a spare 18RG on, so we strapped that down into a wheel barrow.



Next was to paint Grumpy's block... he reckoned floro pink marker paint,



so I said a clear coat of urethane would be needed. The bonus was a lovely crackle effect over the white undercoat!



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The crank went in, followed by pistons with their new rings. We fitted an uprated oil pump, not the raped one we found in a "race" engine he bought. This is how someone changed a mid-sump to a front-sump to fit it in a Celica...



The head was next, we hauled out the 18RG valve extraction tool I'd been working on last time, something we had to make as the standard sort of valve spring compressor won't fit around the wide twin-cam head. The drill press stand was lying in the Woolshed anyway...



Surprisingly it worked, although its really a two-man job.



One guy holds the press handle down and the other uses a magnet and a screwdriver to get the collets out.


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The head had suffered from all the pistons hitting it many moons ago, so we popped it on the block without a head gasket and used a grinder to slowly relieve the combustion chamber and clean up the piston crowns... Why is this?? Well, you are never meant to skim an 18RG head or the piston crown touches the hemispherical head, but that head had been welded up for corrosion in the past and skimmed time and time again as the guy welded. In fact the valve seats were touched by the fly-cutter so much was removed! That explained why grumpy was faster than the rally car!



While Steve was doing this I was distracted by an old kero heater we found in a shed, and I fired it up on the turps used for painting.. Naturally it was blocked up and I ended up stripping it completely and re-buiding it.



After the head was sorted we started putting on the timing chains and cover. This was always a major source of oil leaks, as the motor had been in a crash and the timing cover was smashed then welded. Steve didn't have a flat steel plate so we bought one from the local engineer, about 200x150 and 15mm thick. Then he settledf down with some wet 'n dry sandpaper & the timing chain cover and sanded it straight. The welding had left quite a distortion in it where the head sits, and it eventually lost over 1.5mm.



We made another thick gasket to bring it up to the correct height and then painted the cover. We did the sump as well and fitted them on-


Edited by altezzaclub
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It got colder and the heater was replaced by our old fire again, with the chimney out the door. Not the best idea, but still great to stand around!



Along the way we re-found the linisher Steve had discovered a while back, hoping to use it to shape the roll cage pipes, but apparently you can't get belts for them.



With the head on we started on the cams... and along the way we noticed a problem that had been there since Steve bought the engine..



No oil plugs in the back of the cams!!! The cam grinder must have forgotten to put them back in some years ago, and it was obvious when we checked the cam bearings... the further down the head you looked, the more graunched the cam bearing were as the oil ran out! We searched around the steel junk-pile and found a solution- A stock KE70 spring!



Once cut & lightly filed they could be hammered neatly in with a bit of silicon... Actually I think we did one with silicon and one with araldite, due to a difference of opinion on which was best!


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With the cams in we could start setting tappet gaps, a long job in these motors. With the exhausts all fine we found the inlets had two valves with no tappet gap, one with 12thou as it should, and one with 24thou... The first thing to do was undo the cam bearings 5thou and re-measure, and repeat until we had a gap on those two tight ones. Turned out one was about zero gap to slightly negative, and one was about -10thou!


this was quite troubling..


In theory they should be around 12thou, even with Steve lapping them in. The exhausts were fine. There is only the valve length, the shim thickness and the cup involved, so we pulled the cams out and measured all the shims and all the cups.



they were all fine, so it was as puzzling as ever. We thought maybe the big valve gap was due to a bent valve, so we had to build a tool for a leak-down test. First job was to drill out a spark plug..



yeah, we broke two as the drill bit was juuust too big! So a smaller bit and the third one was copper core..



that allowed us to screw it into the cylinder with a brake hose on it that had a schrader valve in from a ruined rally tyre. The compressor tyre pump gun put 100psi into the cylinder-



We used a bit of tube to listen for leaks in the ports, and thought a couple of valves were dodgy, but not really leaking, so finally decided to pull the head off again. We had already ordered new shims of the various sizes needed but they would take days and days to get to us.



We tipped the head upside down and filled all the combustion chambers right up with turps. After a couple of hours they hadn't leaked at all! We checked everything and all seemed fine, and I can't see how the motor ran with those (lack of) clearances, and I can't see anyting that could cause them! Seeing we had it off we measured the combustion chamber, the head gasket and the piston crown height and figured out it has 11:1 compression!



..and we were out of time! So I'm back in Orange while Steve has 6weeks of Uni, we still have an 18RG to finish, and the rally car got nothing done on it really! Richo is happy tho', blasting about in his 345K Ke30!

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  • 3 weeks later...
  • 2 weeks later...
  • 2 months later...
  • 2 weeks later...

I must have forgotten to reply to this?!


It was awesome to meet another Toyota enthusiast when I couldn't find my mates or our car haha :)


Dad just put the Auto Action writeup on the Tilton Interiors Evo on the table too!


I'm trying to find your build thread because I'm sure I remmember reading one on your Red AE71 years ago when I was trying to buy a 4AGE AE71 back in school...


Tell me you're gonna give rallysprints a go with that spare Corolla shell? :)


I've been flat out doing a 4A-GE conversion for my daily, just finished stripping the donor car... Then off to China for two weeks.


Altezzaclub should be up at the start of next month and we can finally build a rally car!




hey man, I'm the guy you met at WTAC on saturday!



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  • 3 months later...

...and suddenly its February 2015! A week spent getting the 4AGE finished in the KE70 got that out of the way, a total side-track from building a rally car. Then another week or two finishing the 18RG and putting it in Grumpy.


First it was back to the head assembly, sorting out tappet gaps and then fitting cams These were timed using a dial gauge as they are 310deg cams with no clearance between the pistons and the head, and luckily having adjustable cam gears. We made up a lever to turn the amazingly tight engine and to carry the protractor.



Then it was a case of bolting everything onto the outside of it-



and we even polished the extractors!



With nice old-fashiond designs you take the whole front off the engine bay nad it becomes much easier to get motors in and out.



A day spent getting it running and sorting carbs and tuning, and it runs! Just as grumpy and hard to start as ever, between the cams and the carbs. So we drove it straight over to the tank shed and parked it. Now, onto the rally car!

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  • 2 weeks later...

Last year I made a mock-up of the main hoop in waterpipe just to get it to fit exactly. This was left in the pile outside the woolshed and now it cannot be found! We blame the cows... this one was caught eating a K motor when we arrived one day, and we've seen them kicking pieces of steel around the place like footballs. If that motor vanishes I'll know who's responsible!



So we started again, with my fitness fanatic friend pumping iron...



We got the main hoop so it jammed in nicely, welded a brace on it and drew around it on the floor. Then we could measure sides and angles to get a reproducible engineering drawing.



We did a lateral as well, as it is a 3D object and not in one plane. We raised one end on a block of wood while we put the second bend it it to make it kick out up the A-pillar.



Then the tube we bought went off to a tube-bender in Tamworth and we picked it up later that day, all beautifully bent. A close enough fit, I couldn't have done better if I wanted too! Next was cutting short 44mm lengths and machining the ends into shark mouths so they fit the main hoop at 90deg. They will be the welded stubs that our 38mm laterals and braces slide into and bolt up. That way most of the cage will be removeable.


I popped back to Orange this weekend and left Steve cutting 3mm panel for the feet and mounting boxes. Tomorrow I'll head up and we should be able to tackweld lots of it together before taking it down to the man in Tamworth to be welded up properly.


Added to that will be the new seat mount bars we had to make as the rally car registration regs called for bigger box section than we'd used.... So we made them again, from the sill by the B-pillar to the tunnel where they bolt on and a piece that goes inside the tunnel between the two bars to strenthen the tunnel up. All that can be welded now too.

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Now, the springs in post #32 above.... The Celcia Kings springs are too wide to fit up inside the turret, but they will fit upside own as the 'bottom' coils get smaller in diameter. However the top won't fit on the spring base as it has a small diameter groove for the spring end, and we would have to remake the top spring mount.


The KE70 springs fit in the turret, but won't fit on the Celica's small spring base...


However! One KE70 spring is listed a having small spring base. Its actually for AE71s, and worse than that, they were never used in Aussie! So they only occur in AE86s (probably only imports too!) where the strut setup is the same as the Celica but the springs are KE70 diameter up their length.


So if anyone has AE86 stock springs lying around we'd love to buy them, or even just get a photo and measurements!



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We did a lateral as well, as it is a 3D object and not in one plane. We raised one end on a block of wood while we put the second bend it it to make it kick out up the A-pillar.




I thought clause 2.6 (which references 2.5) of CAMS Schedule J, meant that you couldn't make the front leg a 3D object. At least that's how some rollcage fabricators over here have viewed it. Or were you not going to compete in CAMS events anyway ?

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