The Four Cylinder Chevy

[993 Kadett]

Hey Johann, was she also good looking or only your seats ?

The Opel GT's were fantastic, I remember we had three in the company around 1969. One a manual 1900 (if I remember rightly a red one), an A/T 1900 and the best of all (apart from the colour) a metallic green 1100SR engined manual. I tried to buy that one when it came up for sale but you can imagine there was a que for all of them. The 1100 was an incredibly well balanced car, without the ton of weight of the CIH, it felt like a go-kart....& despite the teeny engine it cracked 100mph.
I owned an 'A' 1900 Manta for about 15 yrs...... BVR came up with a very clever inlet manifold for two sidedraughts to clear the brake masrter cyl on the rhs (still have it & pics of it taken this morning, attached) and ran that package with big valves, a very carefully done cylinder head and a five speed ZF. What an absolutely brilliant motor car, it handled like nothing else on the road in it's day and would cruise at 170 - 180 all day in 5th. I dont want to upset the Ford men here but this is one GM product that was so much more refined than it's Ford equivalent the Capri, it was scary. Again GM did not put together a street version with balls.... just so easy to do.......
The Manta had three mechanical characteristics which made it a refined car rather than a street GT : 1.The gearing....the 1900 ran a 3.45 final drive which was simply stratospheric....& 2. The engines rather big and heavy mechanicals & 3 that hopelessly lazy vacuum secondary on the solex..... The following very simple mods: 36DCD (mechanical secondary), a lightened flywheel and the 3.67 F/D from the 1600... and you would not believe it was the same car! I did more of those in PE than I can remember.

[Johann65]

Take a look at the 75 Chev Kommando with the 84 Comaro/Vette motor and see what GMSA should have produced. The AQ body is so close to the Camaro even the door handles are the same!!!. The 84, 305 without all the emmision control pumps etc is flexing the body and if I remove the viscous fan using only the electric fans on the Qtr mile, I am sure it will turn some heads at MIDVAAL!!!
Sure Ben Morgenrood would have liked it!
Will be fitting HD shocks tomorrow and do the brakes thereafter.

Front.JPG (24.19 KiB) Viewed 7063 times

82178_1972_Chevrolet_Camaro_Z28_2-Door_Coupe.jpg (29.93 KiB) Viewed 7063 times

[993 Kadett]

That is a cool looking package, like the colour and sure that Ben wpuld approve. It is great to see that you have done what so many of us aspire to do in our older years and that is actually build a road car to fire up the soul, well done. It may interest you to know that GM imported a good number of 327/350 Kingswood sedans, all white if I rember rightly, for the police. Those were great Q cars & would just love to know where they are today - just one of them!

[Johann65]

That is a cool looking package, like the colour and sure that Ben wpuld approve. It is great to see that you have done what so many of us aspire to do in our older years and that is actually build a road car to fire up the soul, well done. It may interest you to know that GM imported a good number of 327/350 Kingswood sedans, all white if I rember rightly, for the police. Those were great Q cars & would just love to know where they are today - just one of them!

By the way Paul,
Have you noticed my 65 Chevelle Malibu? Saw it being assembled in 1965 and recognised it in 2007 standing on rocks. Power windows, Powerglide 230 CID. Most models were Chevelle 300's. I have the original 1965 GM Factory Manual with all the specs right down to the bolts and nuts and the floorshift conversion> The colour scheme is based on the original "Special" request by the first owner from Westonaria . Daily runner

[993 Kadett]

Sorry Guys, been away again and finding it difficult to keep coms over the last week or so. Johann, that Chevelle is great and really nice that it sounds that you have kept it original. The powerglide tranny is still an amazing piece of engineering for its time, who would ever have thought that a two speed transmission could do the job so well. I would like to get hold of one of the later models perhaps even an Acadian Beaumont with the Coke Bottle styling to do a 292 with some work on it, but just cannot think of building anything for the next year or so. Nevertheless if you hear of a good one......

I should have posted the last bit on the L4 V8 some time ago so here it is a bit late, unfortunately no pics survived on this one but I can tell you that a V8 head on an L4 makes for a very neat looking engine!

L4 ..V8
Fitting a V8 SB head to an L4 Chevy is a tricky task when using a stock 4 cylinder block, however it can be done for test purposes and this was another of the experimental projects carried out as a feasibility study at the time. As mentioned before, the basic L4 engine block is still available today in the USA both as an Iron casting and in Alloy form, specifically machined to take V8 heads from Chevy, Ford and Mopar.
Firstly, the job was initially undertaken in 1974 as an open ended experimental exercise rather than a committed project, the parts were available and marketing were making noises about the then current range of four cyl engines being a bit ’old’. There was no way we could shift to imported engines in production so it seemed a reasonable option to do the exercise and see what happened.

With Bore spacing between the SBC and L4 identical at 4.4”, the major difference in head attachment between the stock 2.5 and the V8 was the bolt pattern. The V8 having 5 bolts per cylinder and the L4 having 4. This resulted in some of the V8 bolt positions being smack in the middle of water jacket apertures on the L4 block joint face. Our first attempt involved welding plugs into the offending areas and redrilling and tapping the bolt positions to fit studs as opposed to bolts. We managed this on two bolts out of four required to be plugged but the welding had hardened the block on the others to the extent that no drill known to man could do the job. One scrapped Block. I began to understand what Meissner had gone through in cutting up the blocks for Y151 to move the oil galleries on the Ford Twin Cam! .
We could, at that time, have had a special block cast with closed off apertures but this would have taken some time, so we proceeded with the rework route.
The second attempt was to block the water jacket apertures completely by machining and then matching stepped plugs to fit and using epoxy adhesive, thus closing all the apertures. We had still to weld in two areas to retain some deck strength but used better annealing tricks to get the final product ‘soft’ enough to drill and tap. With that done, we milled the V8 water jacket aperture positions into the block. The head was fitted on securely knowing that the a few of the new bolt locations were not as strong as they should be.
The next task was selecting rocker ratio. The two engines have differing rocker ratios (1.75 on the L4 vs 1.5 on the SB). One could keep the stock valve arrangement on the Cylinder head and change the camshaft profiles to suite…. or…. as I decided, to move the rocker posts on the V8 cyl Head in order to keep stock camshaft type unmodified and run standard L4 1.75:1 rockers.
This mod would allow us to do a direct comparison of the cylinder heads by keeping all performance related parts, other than the head, the same as the stock 153 engine. The cylinder head selected was therefore a 307 unit with the same size valves (1.72 X 1.5 ) as the 153.
With the cylinder head in place, two issues remained. One was fabricating a water manifold and thermostat housing bolted to the inlet side of the head and Two was fabricating a closing plate to cover the now exposed pushrods and ensure oil drainage to the sump. With those two fabrications complete the engine was assembled with the same compression ratio as the 153. (8.3 actual)
Again in an attempt to keep the basic package as similar to the std engine as possible, the inlet manifold was fabricated to take the same 36DCD carburetor by using a stock Firenza 153 manifold matched to one half of a cut back alloy V8 inlet, the result looked quite neat. The exhaust manifold a stock SB rams horn.
Due to the fact that the mods carried out on the block face were not good enough to sustain a long term head gasket seal, the engine was run through a very short brake-in cycle on the road and taken straight to the rolling road.

Power figures showed a 12 bhp gain without any optimization - 86 to 98 bhp. @4400rpm

I guess the hit rates for projects of this nature are very low at the best of times and this being a very radical departure from conventional thinking at the time, the exercise never went further than the first prototype. The fact that the concept is still alive and well as an aftermarket package today provides some consolation just to know that it could have worked.
Naturally & again referring to a competition version, the ultimate power with this package would have been pretty close to 100bhp per litre in any engine size config we chose.

This was a great last attempt to produce something different for the General at the time and it could have worked. During the period 1974 - 1977 there was a huge amount of pressure on GM to intro more modern engines, mainly because of the Japanese onslaught. My view was that we should maximise the potenrial we had with the big L4's and simply create a cult following by doing so.... that thinking never got off the ground and the L4's and L6's just died a quiet death without any changes right up to their demise in the 80's.

Anyone remember the RTS? P

[Johann65]

Hullo Paul,
Regarding the epoxy filling. I modified a L6 Inlet manifold (ex rochester) to take a 38 Webber lengthwise and gave it to Ridgeback. I used exactly the same epoxy filling and machining procedure. Last I heard the conversion is working well and he could hear the growl of the 38 Webber

Paul have a chat with Graeme, He knows of a 67 Beaumont that is around. There is one (Sport Sedan) in Walkerville but the condition is poor.

The joy of GM based engines are their interchangeability. I am sitting with a Trans Am Steering pump and all it requires is to have hoses replaced and bolt on!! Alignment is spot on!!!

The RTS? It must have been after my time and honestly I was never part of the engineering team except for the trim.

[993 Kadett]

Thanks Johann, its really between a 70's era chevelle or a '55 stovebolt six. Had a look at a '55 down in Knysna last year and nearly bought it. Reason I did not is that the car needed too much work on the body and ancilliaries and I really do want something in good condition so that just the mechanicals can be "ädjusted".

Epoxy work has, over the years, succeeded in doing wonders. Filling in and reshaping ports on the 8 port 181cid Marine L4 Cylinder head is a good example.

The RTS is an interesting departure from stodgy GM in the late 60's. This was an Opel Kadett modified by Robin Thompson, the "Robin Thompson Special" and sold as new product through the GM network. Engine was the 1159cc Ohv fitted with a modded cam, cylinder head and 36DCD Weber. It was a costly rework because it included a combination cast rocker cover/inlet manifold by Robin. Power increase was reasonable but again the overall package suffered because the final drive was unchanged. That particular Kadett was a big car for its 1159cc and by moving the power up the rev range, the already undergeared car just became breathless in normal driving. Hate to have a go at the system again but we were selling against the very competent Escort GT 1300 and it was really a half arsed attempt by GM to get into a market they did not fully understand. The Kadett had the Escort nailed to the wall in areas of handling and braking. All the car really needed was an altered final drive, lowered suspension and a Hi Rise inlet manifold with a 36DCD and it would have done the job. Instead the cost of the rework at an outside supplier just made the whole thing untenable. I will say that a 1256cc version of the car would have been better but by the time that engine went into production the RTS had been laid to rest.
I have been looking for one of these for years and they should be easy to spot because all were painted bright yellow with matt black striping, anyone have a pic? P

[Ridgeback]

The Weber 38 conversion with the manifold adapted by Johann is a real dream.
The fuel consumption, growl and power puts a smile on my son's face.
Also the fact that he runs with the Golfs in town who can't believe their eyes that a 37 year old car is purring next to them.
I worked out there is 49% more air after the conversion.


Thanks again Johann

[993 Kadett]

Hi Ridgeback, I just love to hear that mods like that work well. Seems like Johann you may have been a trim guy back in the day but a good tech man is worth his weight in gold, keep it going!. What engine/car is this mod running in? P

[ZA Perana]

Thanks Johann, its really between a 70's era chevelle or a '55 stovebolt six. Had a look at a '55 down in Knysna last year and nearly bought it. Reason I did not is that the car needed too much work on the body and ancilliaries and I really do want something in good condition so that just the mechanicals can be "ädjusted".

Epoxy work has, over the years, succeeded in doing wonders. Filling in and reshaping ports on the 8 port 181cid Marine L4 Cylinder head is a good example.

The RTS is an interesting departure from stodgy GM in the late 60's. This was an Opel Kadett modified by Robin Thompson, the "Robin Thompson Special" and sold as new product through the GM network. Engine was the 1159cc Ohv fitted with a modded cam, cylinder head and 36DCD Weber. It was a costly rework because it included a combination cast rocker cover/inlet manifold by Robin. Power increase was reasonable but again the overall package suffered because the final drive was unchanged. That particular Kadett was a big car for its 1159cc and by moving the power up the rev range, the already undergeared car just became breathless in normal driving. Hate to have a go at the system again but we were selling against the very competent Escort GT 1300 and it was really a half arsed attempt by GM to get into a market they did not fully understand. The Kadett had the Escort nailed to the wall in areas of handling and braking. All the car really needed was an altered final drive, lowered suspension and a Hi Rise inlet manifold with a 36DCD and it would have done the job. Instead the cost of the rework at an outside supplier just made the whole thing untenable. I will say that a 1256cc version of the car would have been better but by the time that engine went into production the RTS had been laid to rest.
I have been looking for one of these for years and they should be easy to spot because all were painted bright yellow with matt black striping, anyone have a pic? P

As ever a very interesting posts! I dug out a some magazines from that era and even found a road test on the RTS Kadett, as an aside for the sake of history I am going to take a pretty historic picture, RTS was based in Bergvliet in the Cape, the garage where the work was conducted is a still around and I am told looks pretty much like it did back then, will go and take a pic sometimes. Though warning it may contain images of a certain yellow Ford!

I will find that pic of the yellow RTS on the front cover of the Technicar Magazine, it may take some time as I have CAR dating back from 1957 and virtually all the Technicars!

Thanks again for the insight into this era of motoring in SA!