Ok, this isnt the normal "I want 500 horsepower what should I do?" so please read on.
I bought a KA for 50$, it blew because of the timing chain problem where the cam shaft snaps. So herein lyes my question, what do I need to replace / do to the motor? I am planning on turboing it so keep that in mind... Obviosly I need new cam shafts, is it even worth it to get the jwt ones, or should I just try and get some stock ones if I can find them? On the motor I have now I had the same problem, I had to drop the oil pan because when the cam broke a lot of lil metal shards went into the the block.. What else should I look for? Should I have the rotating assemlby balanced? knife edge the crank? What should I do with the head?
I dont know much about this stuff, and I have had trouble finding any comprehensive guide to engine building, so I would appreciate if you could give a basic idea of what everything does and an estimate on the price.
Any help is very much appreciated, thanks in advance.
help me rebuild my KA
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Structure240sx
- Posts: 5615
- Joined: Sun Oct 06, 2002 5:04 pm
i would invest in a factory service manual. then get the engine on a stand. take off all of the accessories and broken camshaft. bring it over to a machine shop and have them rebuild it in stock form or with new pistons and a timing chain kit. rebuilding an engine is not something someone that doesnt know much about should do. i wouldnt even do it myslef. one little thing done wrong can ruin the engine.
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Structure240sx
- Posts: 5615
- Joined: Sun Oct 06, 2002 5:04 pm
Ok, so stock cams should be good.
I dont want to sound cliche, but I want to reach around 300-325hp, can I just find a reliable machine shop and tell them I want it built to stock specs? I jsut feel like I should be getting more done while I have everything apart. I want to atleast have everything balanced while its all apart.
And if nothing in the block really needs to be touched besides pistons, how about the head? What can I do to make it able to redline higher? Should I invest in some Valve springs and Titanium retainers from ka24de.com? Is there anything else that I can do to the head? port and polish?
I dont want to sound cliche, but I want to reach around 300-325hp, can I just find a reliable machine shop and tell them I want it built to stock specs? I jsut feel like I should be getting more done while I have everything apart. I want to atleast have everything balanced while its all apart.
And if nothing in the block really needs to be touched besides pistons, how about the head? What can I do to make it able to redline higher? Should I invest in some Valve springs and Titanium retainers from ka24de.com? Is there anything else that I can do to the head? port and polish?
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Structure240sx
- Posts: 5615
- Joined: Sun Oct 06, 2002 5:04 pm
Yup, listen to Structure. Pull that engine out, strip it down and bring it over to the machine shop. They will need to at least bore it for rebuild pistons (which are slightly bigger so they can get a fresh cyl wall), but I reccomend that you put some forged pistons in there: especially if you've got the engine apart and at the machine shop anyways. Beyond that, get a nice balance, a full rebuild workup (complete balance (including the clutch and flywheel!), freeze plugs, galleys cleaned, hot tank, new rod bolts, gaskets, seals, bearings, etc etc etc), and maybe a few extra goodies if you've got money.
Good luck man!
Good luck man!
Ok this all sounds good, what sort of dent will this leave in my wallet? Also what do you mean by a mild polish? Same thing as a port and polish? I just want to make sure Im not asking for the wrong thing, its best if I know as much as possible when I go in there and hand them a thick wad of cash, you know?
What kind of power could I expect to run safely with this build? Since I dont have to go ALL out unless Im trying to put down 500+ hp then It looks liek I might be able to turbo it over the winter as well as build it, since the build hopefully wont cost as much as I previously thought.
What kind of power could I expect to run safely with this build? Since I dont have to go ALL out unless Im trying to put down 500+ hp then It looks liek I might be able to turbo it over the winter as well as build it, since the build hopefully wont cost as much as I previously thought.
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Ubernoober
- Posts: 539
- Joined: Mon Mar 08, 2004 6:51 pm
Re: (bcuz)
You mentioned 300 HP as a number. A completely reasonable goal.
I am simply going to kinda summarize what the smarter guys above me said and then throw in my own $0.02.
Cheapest thing you could do: replace timing chain with Nissan kit, replace factory cams, start her up. Not the smartest thing to do with all the trash you said got into the pan. A better choice would be a full rebuild. You will have a fresh engine and no gnarly little flakes of metal will show up later to ruin your engine and your day. How would you like to plug an oil galley, lose pressure, burn your turbo, and spin a bearing from a sliver of aluminum hiding in your engine. Ick.
Take the engine to a reliable machine shop. Ask for a factory rebuild but use forged pistons. Lower compression is your choice but for 300HP the concensus is generally the Arias 8.8CR or Ross 8.5CR. Any good shop will hot-tank or chemically clean the block, magnafux (check for cracks) the block and crank, and measure all tolerances to determine if you need to resize bearings or not. From there they should be able to quote you exact price for all machining and assembly required, if they already haven't. Always have all plugs removed prior to cleaning and replaced. Always use new main and head bolts. If you resize the rod ends always use new rod bolts. New gasket set since the darn thing is already apart (I like Felpro).Thats it for the basics. This will deliver reliable power (this assumes tuning competence. Anything can and will break). Additional stuff is just a safety margin or a comfort thing added as a wallet allows.
Extras: Full rotating assembly balance. Most shops will perform a basic balancing job, but good shops will match piston and rods to one another, then balance the entire rotating assembly. I like this and will pay for it every time.Crank and/or Rod mods. Nitriding, shotpeening, knife-edging, micropolishing, lightening, cryo, you name it. All have their benefits. The stock crank is not a weak unit and will do 300HP without complaint. Doing work on the rods can gain you a margin of safety for detonation, but if you are running correctly should handle 300HP fine. Excess RPM will be bad for stock rods. Knife edging a crank allows it to "slice" through any oil that may be sloshed up on acceleration or in a turn. Less resistance and foaming of the oil. It also makes the crank more efficient at flinging the oil off itself. Marginal benefit for daily driving.Nitriding is chemical surface hardening, the crank will have to be checked for straightness after this. Shotpeening is impact surface hardening. Both are trying to stop surface risers from propogating microcracks which can develop into failure points. Polishing/removing stress risers off the entire rod/crank and then surface hardening is also a method. Unless you make big power or rev high, I can't see paying for this. Maybe on the rods.Lightening the KA valvetrain. This would include titanium retainers and the like. Why? The KA valvetrain is not a weakpoint in this engine as far as I have experienced and read. Its good stuff up there. Well, except for that gawdawful timing chain. The new Nissan timing chain kit fixes the problems there.Headwork. A "port" is reshaping and resizing the ports. A "polish" is a fine tasting sausage, or alternately a guy from Poland. Also, A "polish" means that the port is cleaned up of factory flash and a small amount of polishing and radiusing of corners, but no dramatic changes to port shape or size. Simply removing factory flash around the valve seats usually offers the biggest gain. Not necessary but if you have a steady hand and some spare time, its not difficult. DO NOT damage the valve seats, unless they are recessed and shot and need replacing anyway.
Hopefully the smarter guys will come back and correct any errors.
I am simply going to kinda summarize what the smarter guys above me said and then throw in my own $0.02.
Cheapest thing you could do: replace timing chain with Nissan kit, replace factory cams, start her up. Not the smartest thing to do with all the trash you said got into the pan. A better choice would be a full rebuild. You will have a fresh engine and no gnarly little flakes of metal will show up later to ruin your engine and your day. How would you like to plug an oil galley, lose pressure, burn your turbo, and spin a bearing from a sliver of aluminum hiding in your engine. Ick.
Take the engine to a reliable machine shop. Ask for a factory rebuild but use forged pistons. Lower compression is your choice but for 300HP the concensus is generally the Arias 8.8CR or Ross 8.5CR. Any good shop will hot-tank or chemically clean the block, magnafux (check for cracks) the block and crank, and measure all tolerances to determine if you need to resize bearings or not. From there they should be able to quote you exact price for all machining and assembly required, if they already haven't. Always have all plugs removed prior to cleaning and replaced. Always use new main and head bolts. If you resize the rod ends always use new rod bolts. New gasket set since the darn thing is already apart (I like Felpro).Thats it for the basics. This will deliver reliable power (this assumes tuning competence. Anything can and will break). Additional stuff is just a safety margin or a comfort thing added as a wallet allows.
Extras: Full rotating assembly balance. Most shops will perform a basic balancing job, but good shops will match piston and rods to one another, then balance the entire rotating assembly. I like this and will pay for it every time.Crank and/or Rod mods. Nitriding, shotpeening, knife-edging, micropolishing, lightening, cryo, you name it. All have their benefits. The stock crank is not a weak unit and will do 300HP without complaint. Doing work on the rods can gain you a margin of safety for detonation, but if you are running correctly should handle 300HP fine. Excess RPM will be bad for stock rods. Knife edging a crank allows it to "slice" through any oil that may be sloshed up on acceleration or in a turn. Less resistance and foaming of the oil. It also makes the crank more efficient at flinging the oil off itself. Marginal benefit for daily driving.Nitriding is chemical surface hardening, the crank will have to be checked for straightness after this. Shotpeening is impact surface hardening. Both are trying to stop surface risers from propogating microcracks which can develop into failure points. Polishing/removing stress risers off the entire rod/crank and then surface hardening is also a method. Unless you make big power or rev high, I can't see paying for this. Maybe on the rods.Lightening the KA valvetrain. This would include titanium retainers and the like. Why? The KA valvetrain is not a weakpoint in this engine as far as I have experienced and read. Its good stuff up there. Well, except for that gawdawful timing chain. The new Nissan timing chain kit fixes the problems there.Headwork. A "port" is reshaping and resizing the ports. A "polish" is a fine tasting sausage, or alternately a guy from Poland. Also, A "polish" means that the port is cleaned up of factory flash and a small amount of polishing and radiusing of corners, but no dramatic changes to port shape or size. Simply removing factory flash around the valve seats usually offers the biggest gain. Not necessary but if you have a steady hand and some spare time, its not difficult. DO NOT damage the valve seats, unless they are recessed and shot and need replacing anyway.
Hopefully the smarter guys will come back and correct any errors.
Oh, I dont plan on running more then 350 on this build... thats going to feel like a rocket to me already
I just was saying that I thought I would need to do a much more serious build for 350, however it seems that I dont need to replace all the internals. So therefore I can turbo it a lot sooner then I thought
Oh and Uber, what tools do I need to do a polish on my own? and dont tell me a nice charcoal grill Is there a write-up on this somewhere?
I just was saying that I thought I would need to do a much more serious build for 350, however it seems that I dont need to replace all the internals. So therefore I can turbo it a lot sooner then I thought
Oh and Uber, what tools do I need to do a polish on my own? and dont tell me a nice charcoal grill Is there a write-up on this somewhere?
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Structure240sx
- Posts: 5615
- Joined: Sun Oct 06, 2002 5:04 pm
i beleive fianat had a post on machine shop prices to have certain things done for the rebuild. its actualyl not that expensive if you bring them the enigne out of the car already.
man, just wait til you hit 300rwhp, then your talking about making the car go sidways at 65mph trying to go straight.
an air die grinder will be able to do the port and polish. whne i said mild polish i meant to lightly go though the airways in the head jsut to smooth them out some, not to take away alot of material. the KA head is aluminum i wouldnt want to weaken it too much. leave that to the pros with lots of experience
man, just wait til you hit 300rwhp, then your talking about making the car go sidways at 65mph trying to go straight.
an air die grinder will be able to do the port and polish. whne i said mild polish i meant to lightly go though the airways in the head jsut to smooth them out some, not to take away alot of material. the KA head is aluminum i wouldnt want to weaken it too much. leave that to the pros with lots of experience
hehe ok thanks, Ill search for that thread, and look into this air die grinder at home depot or something.
Im getting so excited .. Im going to have to start saving. Im saving half my income for school for next year already, looks like 3/8 of my income is going to be put away for my car. Ill just get more hours at my job, make more money, and have less time to spend it! All for my car... god Im nuts
BTW I would like to thank everyone that has posted and helped me out, and everyone that has held back thier "you f*** newb" comments.
I think these new forums help a lot. Theres a lot less fighting when the SR and RB and CA and KAT guys arent all mingling.
Im getting so excited .. Im going to have to start saving. Im saving half my income for school for next year already, looks like 3/8 of my income is going to be put away for my car. Ill just get more hours at my job, make more money, and have less time to spend it! All for my car... god Im nuts
BTW I would like to thank everyone that has posted and helped me out, and everyone that has held back thier "you f*** newb" comments.
I think these new forums help a lot. Theres a lot less fighting when the SR and RB and CA and KAT guys arent all mingling.
ah Ive been around nico for a good 3 years I think, mostly lurking, but now I am getting more direction into what I want to do. Before I didnt know if I wanted an SR, RB, KAT... a drag car, drift car, ect ect..
But thanks mostly to nico I am understanding cars in general more and the more I understand the the more defined my goals are.
And hopefully one day I can add to the community since right now Im just soaking everything up.
But thanks mostly to nico I am understanding cars in general more and the more I understand the the more defined my goals are.
And hopefully one day I can add to the community since right now Im just soaking everything up.
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Ubernoober
- Posts: 539
- Joined: Mon Mar 08, 2004 6:51 pm
Re: (Structure240sx)
Thats the good stuff. It will go fast with just sanding rolls. If desperate, a long-nose dremel will do the job. It just takes patience.Try here for an idea of what Structure means. http://www.sa-motorsports.com/diyport.shtmStructure240sx wrote:an air die grinder will be able to do the port and polish.
And as always with NICO, ask away....!
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Nismo_Freak
- Posts: 10314
- Joined: Wed Jul 24, 2002 10:42 pm
- Car: 89 Nissan 240SX
Re: (bcuz)
One suggestion on the die grinder bit would be to try and pick up a cheap cylinder head from any kind of vehicle to try your abilities on first. Use bits that don't remove alot of material so you can learn to balance the grinder and learn how fast it will remove material.bcuz wrote:hehe ok thanks, Ill search for that thread, and look into this air die grinder at home depot or something.
Im getting so excited .. Im going to have to start saving. Im saving half my income for school for next year already, looks like 3/8 of my income is going to be put away for my car. Ill just get more hours at my job, make more money, and have less time to spend it! All for my car... god Im nuts
BTW I would like to thank everyone that has posted and helped me out, and everyone that has held back thier "you f*** newb" comments.
I think these new forums help a lot. Theres a lot less fighting when the SR and RB and CA and KAT guys arent all mingling.
don't try and use a dremel, they suck. you can get an electric die grinder for less than 30 bucks on ebay. they are cheap and disposable (ours lasted a few months before blowing up) but man that is such a valuable part when working with metal.if you can afford it, ideally it would be nice to get a decent one. if you have a compressor, get an air powered one. but def. don't use a dremel, trust me its like comparing apples to oranges.
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WDRacing
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I used a dremel for one of my RB20 heads, it took me a whole week to port, then I did one with my high speed air die grinder, I figured it would take awhile....I totally ruined the valve seat area in like 7 seconds. If you don't have a spare head, grab anything made from aluminum and just practice shaping it. Way worth it in the long run.
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yelnatsch517
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Re: (WDRacing)
OK when you get the quote on how much all that stuff is going to cost can you post it? I might be doing something similar in the future.