Preparing For Honda K24a3/AST5 6spd Conversion

Michael Albers

Daily Driver
:(:(:(:(:(

I hate to say, it looks like the grease in the cylinder may have been put there to make the rings seal to fake out a compression test.
Definitely not cool!
 

X1/9Cruiser

True Classic
It might be cheaper in the long run to source a new block. They must be fairly common and plentiful. I'd give eBay a try maybe...
 

lookforjoe

True Classic
:(:(:(:(:(

I hate to say, it looks like the grease in the cylinder may have been put there to make the rings seal to fake out a compression test.
Definitely not cool!
It might be cheaper in the long run to source a new block. They must be fairly common and plentiful. I'd give eBay a try maybe...
The grease /goop is actually a mix of the oil I added to the bores after I removed the manifolds - I didn't want them sitting exposed while it in the cold garage - when I subsequently turned the motor over, it must have mixed the water/rust/oil into that paste. Since the motor was completely intact with manifolds, I'm not sure how fluid ended up in one bore, unless it had a bad head gasket.

Blocks aren't cheap. From what I can find, it would cost me $350-500 to buy one delivered, and then I'd still have to deal with hone/rebore, so not much point in that. Better to stick with the devil I know, at this point. I guess I could buy another complete motor for 700-800, but it would still be questionable to me at this point. Unfortunately too much time has lapsed for me to do much of anything with the CA dismantler/importer I bought it all from.
 

lookforjoe

True Classic
Nippon Racing pistons were recommended on K20a.org. Those can be had for about $200 a complete piston/ring set for conventional NA build spec (std., .020, .030, 040") so this may not be as bad as I was expecting. I really didn't want to go the Wiseco route, as nice as forged are, they always consume some oil when compared to a cast piston install, in my experience.
 

Pete Whitstone

True Classic
Nippon Racing pistons were recommended on K20a.org. Those can be had for about $200 a complete piston/ring set for conventional NA build spec (std., .020, .030, 040") so this may not be as bad as I was expecting. I really didn't want to go the Wiseco route, as nice as forged are, they always consume some oil when compared to a cast piston install, in my experience.
I'm surprised that they're not forged from the factory. With as high a piston speed as this engine sees (one of the highest in a production engine), you would think a forging could be lighter than a casting.

Pete
 

lookforjoe

True Classic
I'm surprised that they're not forged from the factory. With as high a piston speed as this engine sees (one of the highest in a production engine), you would think a forging could be lighter than a casting.

Pete
There is that - however the K24 does have a lower rev limit. I was just thinking of the fact I ran my Volvo to around 9K with the large frame turbo, but I did have Wiseco's in that.

In any event, I don't want to use forged pistons, so I'm happy this option exists for this market. This would be what I had in mind from them

Crank journals all look good



 

lookforjoe

True Classic
Too early for this yet - however I will be adding "iVTEC" emblem to either the spoiler or the front fenders - I'm thinking just one on the spoiler

Engine and pistons are at the machine shop - hoping to get it back before next Friday, We'll leaving for a week visit to my Aunt in 'Vegas for Spring Break next weekend.


 

lookforjoe

True Classic
I think for SS and small stuff like this, a water cooled torch is overkill. It is SUPER useful for heavier gauge aluminum as the amperage is way higher and you can keep welding without melting your torch. Air cooled should be fine.
Pulled this post so it would tag you - looking at your frame install pics, I noticed your MWB forward stanchion (where it bolts to the stock crossmember point) has a circular cut out. Did you do that for cable (?) routing, or did they used to come with that hole?

Screen Shot 2019-04-15 at 9.30.35 PM.png
 

darwoodious

Darin Nelson
I cut it out to make it easier to run the shift cables thru there. I plan on running the shift cables thru the same hole that the stock shift rod runs thru. Should be plenty strong enough and no crap will load up there as it is open at the bottom for bolt access.
 

lookforjoe

True Classic
I cut it out to make it easier to run the shift cables thru there. I plan on running the shift cables thru the same hole that the stock shift rod runs thru. Should be plenty strong enough and no crap will load up there as it is open at the bottom for bolt access.
I'm realizing that dropping the subframe if the need arises is going to entail removing much crap. Even if the cables weren't run through the subframe, it looks like they would need to be disconnected from the shifter & removed to prevent entanglement.
 

lookforjoe

True Classic
Got the block back today. #4 still has a shadow where the rust was deepest, just above the top ring (was bored & honed for 87.5 pistons). My machinist is absolutely confident it will not be an issue in use. Assembled the bottom end. Used HondaBond HT, which is what many recommend, but it not the specified sealant.

Crankshaft, main & thrust bearings in. Carrier blockplate installed, Oiled mains bolts torqued in sequence; 2 stages (22ft/lbs, 56º), then outer M8 bolts in sequence to 16ft/lbs.
At this point I realized I hadn't installed the oil squirters. Bit fiddly with the crank in place. Little bit of cursing there.

Then assembled the new NPR pistons on the con rods & installed piston ring sets. Installed each piston/rod assy. with new King bearings & torqued oiled conrod cap bolts in 2 stages (27 ft/lbs, 120º). I found that I had flipped two of the rods when I attached the pistons, so the cap casting " RBB 29" on 3 & 4 face the opposite way - pistons markings all face front of motor as intended and caps are properly oriented relative to rod . No functional difference, but it bothers me a little. Not enough to cause me to take the pistons back out though :D





Then I installed the Baffle, Oil Pump, crank gear, pump chain, guide & tensioner, followed by the Blox baffle kit and finally the oil pan.





I'm going to try & get the head back on before we leave for Las Vegas tomorrow evening. Otherwise it will just have to wait a week.
 
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lookforjoe

True Classic
Weather here is so miserable, I've been doing work around the house & yard. Finally got back to the motor reassembly, and put the head back on. 3 stage torque sequence; 29ft/lbs, 90º, 90º.

I put the rocker assy back on also, that's fun. Have to keep the damper properly aligned, and I didn't realize the rocker shafts are keyed , so if you don't have at least four of the cam cap bolts in place, it doesn't work. Had to do it over. The rear cap also has to be sealed with HondBond, so that had to be cleaned off & re applied. Installed with just the exhaust cam for right now, '07 TSX (higher lift) cam is incoming. I'm getting the VTEC gear modifed to allow an additonal 5º or advance, fpor a total of 30º, which seems to be the safe limit for K24, with higher comp pistons.

Still cleaning the HondaBond off the breather housing/ancillary box.





Material will be removed from the right side of the two lobes to allow 5º additional rotation

 
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kmead

Old enough to know better
Quite the complex set of objects. Really lovely engineering but not a nice one to have to assemble (particularly for the first time).

Spring has finally sprung here this week, rain all week and this weekend will be all sunshine and warm so the leaves will be quickly unfolding.

Happy to see progress for your sake.

How is that Volvo coming along? Now that is an amazing puzzle.
 

lookforjoe

True Classic
Quite the complex set of objects. Really lovely engineering but not a nice one to have to assemble (particularly for the first time).

Spring has finally sprung here this week, rain all week and this weekend will be all sunshine and warm so the leaves will be quickly unfolding.

Happy to see progress for your sake.

How is that Volvo coming along? Now that is an amazing puzzle.
With the inclement weather, I can't start pulling my Volvo apart. I need at least 3-4 consecutive dry days so that after work I can take the interior out, run the wiring, drop rear suspension & fuel system, drop transaxle, replace clutch & flywheel, install all the AWD parts, then modify exhaust system to fit around the AWD drivetrain. That part may involve R&R the rear subframe more than once, as it snakes through all that. At the rate we're going it's gonna be June before I can get to it :(
 

lookforjoe

True Classic
Water Housing cleaned & installed. T/stat adaptor & K -Tuned water elbow housing installed. Also got the crank seal replaced, the VTEC controller and the oil pressure adaptors in.



Runners going back on



Problems, problems.

Can't get a water pump that fits, it seems. I ordered a GMB 135-1510, which is intended for the RSX, having the oil cooler port I require. The flange bolts don't align.

With 2 bolts in on the left:







Not sure where to go from here. I'm not expecting that if I spend $$$ for an oem RSX pump that it will fit any better. It seems unlikely the GMB has a casting defect of this magnitude.

In addition, the oil cooler hose 19422-PRB-A00 doesn't fit either.


EDIT: My water pump is labelled RBC. I'm going to try the pump I found with that in the part number - 19410-RBC-000 (BA 131-2373). Listed for CIVIC SI & Acura CSX. I need to know what pump will fit.

EDIT - 19422-RRB-A01 is likely the correct hose for the JDM K24A3.
 
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lookforjoe

True Classic
19410-RBC-000 (BA 131-2373) pump arrived. Casting is identical to original. I'll have to check the Civic parts catalogue for the hose that didn't fit also. Also ordered the MFactory LSD.

Higher lift intake cam arrived today. Have to wait for the modified VTEC gear before I can install the cam, assemble the timing components & button up the motor. After that, I can install the rear main, flywheel, clutch and then mate the engine / transaxle & move forward.



 
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lookforjoe

True Classic
Pulled the transaxle apart today, that casing is a PITA to separate!



removed the diff - bolts are NOT left hand thread as listed in the DIY's I found





Case needs a serious clean







new bearings installed on MFactory posi, ring gear torqued to 89ft/lb



The input shaft seal is installed BEHIND the bearing instead of from the bell housing side. Which means that pretty much no way to replace the seal without also replacing the bearing. That's the kind of info that should be listed in the frickin CATALOG!!!! No reaon there couldn't be a notation that indicates required bearing # when you try to purchase the seal.



A confusing element here is the mainshaft rear bearing, the one that sits in the outer casing. It is described in the shop manual as an "angular ball bearing" without any further clarification. It has two different size bearings caged, and the outer race has a channel that the bearings can move fore/aft in (not shown in the manual pic below)



Honda-Tech.com has a thread that contains a touch more info



The thing is, this bearing cage can ride laterally on the inner race, and pivot on an angle. It feels like it must be shot, but there is no radial play between the inner & outer & no evidnece of wear markings, etc. I have to assume that that is what Honda defines as "angular", I wish I could ge tmore precise info. I found a good rebuild thread on K20a.org, however no one made mention that one should not be alarmed when inspecting this bearing, and I can't find any posts where it is remarked upon, except for one person saying his was "wobbly" (which it is, in a sense). This kind of vague info bugs the crap out of me. It's a $50 bearing, so I don't want to order one just 'because'!
 
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lookforjoe

True Classic
Put the transaxle back together this morning. Assembly lube in all the bearings & sleeves. Didn't change the input shaft bearing or seal. Not enough evidence to support waiting a few days for a bearing to replace the one I'd have to damage upon removal. Left the Mainshaft bearing as well, again no evidence that it's movement is untoward.

This little bugger has to be fiddled into the groove in the bearing once the case is bolted back together.



Case sealed with HondaBond, sensors, plugs, detents & shifter assy.reinstalled. New axle seals installed (left SKF 159888, right 91206-PHR-003)
Put 1/2 quart of Honda MTF in it & swilled it around, just to make sure everything stays lubed until whatever point it actually runs.



 
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