Sunday, March 29, 2009

A CLASSIC CAR RESTORATION : HONDA PRELUDE

The 2nd generation Honda Prelude (mfg. code "SBO") was an iconic symbol of mobility, sophistication, effluent, all back in the 80's. I was one of them who considered this as a "Dream Car" back then. I found this baby sitting at a used car dealer in 2002 with 300,000km. Specs. states that this is a 1.8 liter engine with twin carburettor, 12 valves, single cam, 4 wheel disc brakes & 4 wheel independent suspension with individually adjustable camber & castor angle. Compared with the sister Honda Accord, this is the "Ride" to kill for.

The first test drive was pure disappointment. The car was hesitating, pick-up was poor, steering out-of-alignment, sunroof not working ....... but the engine was smooth and goes willingly when rev-up - a typical feature with Honda engines that makes the marque so popular with the race-boys.




Among the items that are worn most in a 300k km car would be the engine. Suspension, brakes and steering would be the next on the list. The engine hoist is positioned for hoisting the engine & gearbox out. Balancing the engine-gearbox weight is very important to prevent tilting during the lift, which will damage other ancillaries if the weight centering is not properly managed



Shown here is the engine being hoisted out with the gearbox attached. This complete overhaul was done in 2005, after a prior cylinder head rebuilt that has failed to produced any results on excessive engine oil consumption, which was due to worn piston rings & pistons.




After the powertrain is hoisted out, the engine bay is cleaned and hand-painted with special anti-rust with matching color. Since there was no hurry, I took my own sweet time to tackle all the nook and corners.





This was how the cylinder head looks like after 3 years of usage. Cyl #2 & #4 appears to have excessive oil, indicating worn piston or rings. Cylinder block boring is definitely on the menu.






The pistons appeared to mirror the diagnosis, with heavy contamination of carbon deposits.







After the cyl block boring, the block is flushed cleaned thoroughly. This is important as the boring generates lots of metal chips and dusts. The block is painted RED, my favorite engine color.






After the assembly is completed, both the engine and g'box is hoisted back into the body as one.







Here it is, sitting right and pretty in the newly painted powertrain compartment. The subframe has been painted yellow to differentiate from the chasis color. This is to help in future maintenance. Bright colors make the dirt, oil stains show up well.






Hi Dad ! When can I go for a ride in the hot-rod ??








CYLINDER HEAD WORKS : Feb 2009
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In 2009, I had some spare time at hand and decided to rebuilt the cyl head due to overheating problem when doing high speed cruise (~140 km/h). My first check was on cyl bore wear, which appeared to be minimal with no indentions on the walls.





The photo shows the cyl head with about 3 years of usage, or 35,000km since the last rebuilt. Engine oil consumption (leakage) appeared to be under control this round with minimal carbon deposits.





Due to carefull selection of petrol pump stations, the intake valve sides appeared to be "clean" as advertised by company "P" and "E". #2 chamber was wet due to earlier direct oil injections during a compression check prior to cyl head removal. The compression reading was 210psi with no change when engine oil when injected.




The cyl head is then sent for surfacing at a local machine shop, with valve seats cut at the standard 30-45-60 degrees angle, with intake at 1.0mm, exhaust at 1.5mm valve seat widths.






I used the standard pencil test to confirm 100% full surface contact for the valve to valve-seat. In this test, a yellow marker was used against a grey (intake valve seat) background.








Here's a closed look, on the exhaust valve.







Yes, a grinding stick with paste is used to ensure a proper surface texture and to verify is the machine shop seat grinding is 100% aligned.







The cyl head, all prep up and ready to be mated to the block.







The block, with all pistons and surface cleaned up very meticulously, and new gasket installed.








The engine after mating the cyl head and block, with intake manifold attached, minus the twin carburettors.








This is all sooooo boring. Just leave me alone for a nap.




3 comments:

  1. How long you take to take out the engine from the bay?

    I and my dad used to take out Accord SM4 engine from bottom.

    It was quite easy in that way.

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  2. 2 persons removing from the bottom versus one person removing the engine out of the bay from the top using a crane ? Besides that, what are the chances of the engine slip and fall down on the person holding the engine from below ?

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  3. Thank you for shared a good topic. I think it will help the people to repair the car and another car instrument. Our variety of parts ranges from suspension kits to motor mounts. View our online gallery for examples of work we’ve done Mustang II IFS Suspension. I think it will a great opportunity to me.

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