Rebuilding my engine, where and what to get
#1
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
My engine is going down, time for a rebuild I guess.
I think I'll do rods, pistons, and headwork if I have the engine out, even though I don't think I'll be pushing a lot of power, just to be safe I guess. Well and I need your suggestions on what to get, I'd like to stay on the cheaper side of things but will pay for a quality product. My friends with sr's run eagle rods with cp pistons, are those any good, or is there cheaper alternatives. Also what do I need for the head? I've never rebuild an engine before so teach me. Let me know what you guys think, I need to do this asap.
thanks,
Mike
I think I'll do rods, pistons, and headwork if I have the engine out, even though I don't think I'll be pushing a lot of power, just to be safe I guess. Well and I need your suggestions on what to get, I'd like to stay on the cheaper side of things but will pay for a quality product. My friends with sr's run eagle rods with cp pistons, are those any good, or is there cheaper alternatives. Also what do I need for the head? I've never rebuild an engine before so teach me. Let me know what you guys think, I need to do this asap.
thanks,
Mike
#2
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Sadly eagle doesn't make rods for the BP. The cheapest "over the counter" rod that I know of are pauter's which are expensive. $800ish. However there is some sort of GB for a custom rod going on on m.net that is supposed to hold some good power while remaining relatively cheap. $4-500ish. I'm sure people will make claims of one aftermarket piston is better than the other, but in reality as long as your block is prepared for the pistons properly then it won't matter. Buy the pistons first and get the machine shop to bore/hone them to the clearances recommended by the piston manufacturer. Also get the machine work done at a place the does import work regularly and preferably has a sunen honing machine and is able to to a plateau hone. This will allow your rings to seat almost instantly.
Get the head cleaned and check valve play side to side to make sure the guides are still good, they might recommend honing the guides. As far as headwork is concerned a valve job, and a mild port polish should be enough. Major headwork can easily cost as much as the rods and the pistons combined. Plus with turbo major flow work isn't needed that much for a street motor since you are forcing air in anyway.
The easiest way to rebuild a motor fast would be to buy the pistons, rods, head studs, complete gasket set. Order a replacement remanufactured crankshaft with matching bearings from rpmmachine.com, its like $150ish regularly with a core(from your motor). Preferably get clevite77 bearings from them with the crank. Number the pistons with a magic marker on the dome when they come in. Disassemble the block, take it and pistons to the machine shop, get them to bore and hone the cylinders to the individual numbered pistons. While the block is there get them to check the deck to make sure it is true, Get them to check the crankshaft bore alignment and taper. Basically make sure everything is within spec. You will need to give them the values out of your shop manual. Bring block and pistons home. Send core crankshaft out so you get your core charge back. Take the block outside and clean out the bores with dishsoap and a cotton wash cloth. Dry them off completely and oil them. Clean out the rest of the block with the soap solution also and try to get it as dry as possible after rinsing. Wrap block in plastic wrap to keep it clean.
Clean your work area of ALL dust. Clean your work area AGAIN. Best place to work if working at home is in the kitchen! It should go without saying that you wear plastic gloves during the entire assembly. Buy a couple boxes and change gloves whenever they get dirty or you change tasks. Less dirt equal happier motor.
Although the crank comes with matching bearings you should check the clearance anyway. Put main bearing halves into block and then put a light coat of assembly lube on them. Drop in the crank, don't rotate it. Put a piece of plastigauge on the crank pin the goes under the main cap (The part you can currently see). Put the main caps on evenly and torque them to 10-20 ftlbs. Dont turn the crank while doing this. Take of the mains making sure not to rock them side to side at all if possible. Use plastigauge guage to roughly verify clearances. Take out the crank and put it on the table and do the same process with the connecting rods. Making sure that you only put lube on the face of the bearing the faces the crankshaft. Verify clearances on the rod bearings. Hopefully everything is good. Next you can go ahead and install the rods on the pistons and put them to the side.
Now you need to make sure the ring gap is to spec. The pistons should have come with the recommended ring gap for particular applications. If not then use the specs from the miata shop manual. Put the rings in individually and push them into the bore with one of the pistons. Use feeler gauge to check gap. If it needs to be enlarged you will need to use a ring filer to file them. Manual ring filers are pretty cheap. Now install the rings on the pistons. Some rings have a top and bottom side and need to be installed accordingly. They will have indicators or instructions. Also the oil ring has to be installed properly, I cannot think or this part off the top of my head but I will look for a link. Once all the rings are on set the pistons aside, preferably put them in plastic freezer bags to keep them clean.
Now clean the main and thrust bearings. Install them into the motor again. Lube the the face generously, both sides this time!, including the thrust bearings. Bolt down the mains to 15ish ftlbs again. Now for this part you need a dial caliper and a magnetic stand to check the end play. Hopefully you can just borrow one since this is the only part you really need it for since your other clearances have been checked by the machine shop. Attach the magnetic stand to the block so that the caliper tip can touch the end of the crank(either side is ok). Take a big flat head and wedge it inbetween the counterweight and the middle main where the thrust bearings are. Now push one way on the screwdriver and take the measurement. Then the other way and take the measurement. You now have your play. If it is within spec then go ahead and torque down the mains to spec in the proper order from the shop manual.
If you are going to be firing the motor soon then motor oil is ok to be used on the cylinder walls. If it will be stored for a while then a light coat of assembly lube should be used. Go ahead and do this
Now clean the rod bearings and install them into the rods and the rod caps. Lub them generously. Align the ring gaps according the the shop manual. Put a ring compressor around the piston so that it can be moved within the compressor with just a little friction. Drop the piston assembly into the bores making sure the exhaust and intake valve reliefs are on the proper sides. IMPORTANT: the pistons should slide into the bores with only the force of your fingers. If you feel like you need to use a dowel and the handle of a hammer etc then you need to re adjust the ring compressor. Never hit the pistons into the bores. You could potentially damage the rings. Do this for all the pistons. Now install the rod caps onto the rods and torque the rods down to spec. Loosen them and tighten them again to spec. This will give you as close as possible to true torque without the use of a rod bolt stretch gauge (too expensive to just one build).
Now the hard parts of the assembly are basically done. From here you can just follow the pictures in the shop manual to put on the other parts and torque them to spec. Make sure you use sealant on places that require, ex. permatex.
As far as the head goes, you might be able to find a place the sells reman heads with a core exchange. This would probably be the cheapest route overall if you dont want to do any headwork yourself and don't already own any tools to disassemble it. It would probably cost around $300-350 for a reman head with core exchange. Then again if you want to do it yourself then taking it apart is pretty simple, you really just need a spring compressor. You will need a brass wheel to clean the carbon off of the valves quickly. Take the head to a machine shop, they will most likely need to resurface it (aluminum heads....) Get them to do a 3 angle valve job if you want. If you arent too worried about a 3 angle job then you could just buy some lapping compound and a manual valve lapping dowel thingy. Just put the lapping compound on the seat and insert the valve. Put the rubber end of the dowel on the valve face and twist it back and forth with your palms like you are making a fire the hard way. Easy peasy. Clean it up and your set. You get the idea. Just put lots of assembly lube on the cams, the whole thing, when you reassemble. Also assembly lube can be used to stick the valve keepers in place on reassembly. Hakuna's webpage has some good info on head disassembly and valve lapping with pics.
I was pretty thorough with the major parts of the engine internal assembly although I may have left out some small details. I haven't assembled a motor in a couple years since I got out of the Honda scene. If anyone can think of anything else I left out then add away. My way of getting the reman crank should save you some good money in the long run because you will have to pay less at a machine shop and it comes with matching bearings.
Brian
Get the head cleaned and check valve play side to side to make sure the guides are still good, they might recommend honing the guides. As far as headwork is concerned a valve job, and a mild port polish should be enough. Major headwork can easily cost as much as the rods and the pistons combined. Plus with turbo major flow work isn't needed that much for a street motor since you are forcing air in anyway.
The easiest way to rebuild a motor fast would be to buy the pistons, rods, head studs, complete gasket set. Order a replacement remanufactured crankshaft with matching bearings from rpmmachine.com, its like $150ish regularly with a core(from your motor). Preferably get clevite77 bearings from them with the crank. Number the pistons with a magic marker on the dome when they come in. Disassemble the block, take it and pistons to the machine shop, get them to bore and hone the cylinders to the individual numbered pistons. While the block is there get them to check the deck to make sure it is true, Get them to check the crankshaft bore alignment and taper. Basically make sure everything is within spec. You will need to give them the values out of your shop manual. Bring block and pistons home. Send core crankshaft out so you get your core charge back. Take the block outside and clean out the bores with dishsoap and a cotton wash cloth. Dry them off completely and oil them. Clean out the rest of the block with the soap solution also and try to get it as dry as possible after rinsing. Wrap block in plastic wrap to keep it clean.
Clean your work area of ALL dust. Clean your work area AGAIN. Best place to work if working at home is in the kitchen! It should go without saying that you wear plastic gloves during the entire assembly. Buy a couple boxes and change gloves whenever they get dirty or you change tasks. Less dirt equal happier motor.
Although the crank comes with matching bearings you should check the clearance anyway. Put main bearing halves into block and then put a light coat of assembly lube on them. Drop in the crank, don't rotate it. Put a piece of plastigauge on the crank pin the goes under the main cap (The part you can currently see). Put the main caps on evenly and torque them to 10-20 ftlbs. Dont turn the crank while doing this. Take of the mains making sure not to rock them side to side at all if possible. Use plastigauge guage to roughly verify clearances. Take out the crank and put it on the table and do the same process with the connecting rods. Making sure that you only put lube on the face of the bearing the faces the crankshaft. Verify clearances on the rod bearings. Hopefully everything is good. Next you can go ahead and install the rods on the pistons and put them to the side.
Now you need to make sure the ring gap is to spec. The pistons should have come with the recommended ring gap for particular applications. If not then use the specs from the miata shop manual. Put the rings in individually and push them into the bore with one of the pistons. Use feeler gauge to check gap. If it needs to be enlarged you will need to use a ring filer to file them. Manual ring filers are pretty cheap. Now install the rings on the pistons. Some rings have a top and bottom side and need to be installed accordingly. They will have indicators or instructions. Also the oil ring has to be installed properly, I cannot think or this part off the top of my head but I will look for a link. Once all the rings are on set the pistons aside, preferably put them in plastic freezer bags to keep them clean.
Now clean the main and thrust bearings. Install them into the motor again. Lube the the face generously, both sides this time!, including the thrust bearings. Bolt down the mains to 15ish ftlbs again. Now for this part you need a dial caliper and a magnetic stand to check the end play. Hopefully you can just borrow one since this is the only part you really need it for since your other clearances have been checked by the machine shop. Attach the magnetic stand to the block so that the caliper tip can touch the end of the crank(either side is ok). Take a big flat head and wedge it inbetween the counterweight and the middle main where the thrust bearings are. Now push one way on the screwdriver and take the measurement. Then the other way and take the measurement. You now have your play. If it is within spec then go ahead and torque down the mains to spec in the proper order from the shop manual.
If you are going to be firing the motor soon then motor oil is ok to be used on the cylinder walls. If it will be stored for a while then a light coat of assembly lube should be used. Go ahead and do this
Now clean the rod bearings and install them into the rods and the rod caps. Lub them generously. Align the ring gaps according the the shop manual. Put a ring compressor around the piston so that it can be moved within the compressor with just a little friction. Drop the piston assembly into the bores making sure the exhaust and intake valve reliefs are on the proper sides. IMPORTANT: the pistons should slide into the bores with only the force of your fingers. If you feel like you need to use a dowel and the handle of a hammer etc then you need to re adjust the ring compressor. Never hit the pistons into the bores. You could potentially damage the rings. Do this for all the pistons. Now install the rod caps onto the rods and torque the rods down to spec. Loosen them and tighten them again to spec. This will give you as close as possible to true torque without the use of a rod bolt stretch gauge (too expensive to just one build).
Now the hard parts of the assembly are basically done. From here you can just follow the pictures in the shop manual to put on the other parts and torque them to spec. Make sure you use sealant on places that require, ex. permatex.
As far as the head goes, you might be able to find a place the sells reman heads with a core exchange. This would probably be the cheapest route overall if you dont want to do any headwork yourself and don't already own any tools to disassemble it. It would probably cost around $300-350 for a reman head with core exchange. Then again if you want to do it yourself then taking it apart is pretty simple, you really just need a spring compressor. You will need a brass wheel to clean the carbon off of the valves quickly. Take the head to a machine shop, they will most likely need to resurface it (aluminum heads....) Get them to do a 3 angle valve job if you want. If you arent too worried about a 3 angle job then you could just buy some lapping compound and a manual valve lapping dowel thingy. Just put the lapping compound on the seat and insert the valve. Put the rubber end of the dowel on the valve face and twist it back and forth with your palms like you are making a fire the hard way. Easy peasy. Clean it up and your set. You get the idea. Just put lots of assembly lube on the cams, the whole thing, when you reassemble. Also assembly lube can be used to stick the valve keepers in place on reassembly. Hakuna's webpage has some good info on head disassembly and valve lapping with pics.
I was pretty thorough with the major parts of the engine internal assembly although I may have left out some small details. I haven't assembled a motor in a couple years since I got out of the Honda scene. If anyone can think of anything else I left out then add away. My way of getting the reman crank should save you some good money in the long run because you will have to pay less at a machine shop and it comes with matching bearings.
Brian
#6
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
I can do carrillo rods for 739 a set. If you buy a set of wisecos from me, they are 695.00
I can do the pauters for 784, or 760 if you buy the pistons from me too..
The pistons are 476, 466 if you also buy the rods.. That includes rings.
#8
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
haha, thanks for the vote of support. I just wanted to show that rebuilding a motor can be relatively easy for the unexperienced wishing to try the first time. One of the huge things in rebuilding any motor are clearances. That is why I recommended getting the reman crank with matching bearings and sending them your crank back. It takes out what I consider the majority of the "guesswork" (term used lightly) involved in rebuilding a motor for the first time. Additionally, the places that sell reman cranks do only that. So they can work them on a larger scale than a local shop, saving you money in the end. Most reman cranks from rpmmachine (they get them from another company) cost $150 give or take including bearings. Thats a hell of a price!
Please keep in mind when reading this that it is not meant to be an end all guide or anything. It is simply a semi detailed overview of the internal build process. Never use the post as a replacement for a shop manual.
Please keep in mind when reading this that it is not meant to be an end all guide or anything. It is simply a semi detailed overview of the internal build process. Never use the post as a replacement for a shop manual.
#9
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Wow, thanks for such an awesome writeup man! Really helps there, cause I have no idea what I'm doing. But I'll most likely take it to a local one man shop that does really good job and very cheap as well.
Why do miata parts have to be so expensive?
I thought I've found some cheaper stuff before but I guess I was wrong. Nester I might hit you up soon for rods/pistons.
What about cams, lifters, stoppers? I think my lifters are dead, they sound pretty bad, should I just replace everything with oem parts, will they be sufficient enough or are there better aftermarket parts. How about cams, I don't see any aftermarket ones available for bp engines, are they that good.
Sorry for a bunch of noob questions, but I just want to do my research and know what I'm doing, and I'm sure it'll help someone else as well.
BTW I think my absolute max power goal is 400rwhp, but I don't think I'll ever go above 350. Most likely though I think I'll stay at about 250-300hp mark, just want it to last.
akaryrye you're right, I still want to sell the car but since the engine is dead, I might as well build it up.
Why do miata parts have to be so expensive?
![Thumbsdown](https://www.miataturbo.net/images/smilies/thumbsdown.gif)
What about cams, lifters, stoppers? I think my lifters are dead, they sound pretty bad, should I just replace everything with oem parts, will they be sufficient enough or are there better aftermarket parts. How about cams, I don't see any aftermarket ones available for bp engines, are they that good.
Sorry for a bunch of noob questions, but I just want to do my research and know what I'm doing, and I'm sure it'll help someone else as well.
BTW I think my absolute max power goal is 400rwhp, but I don't think I'll ever go above 350. Most likely though I think I'll stay at about 250-300hp mark, just want it to last.
akaryrye you're right, I still want to sell the car but since the engine is dead, I might as well build it up.
#10
Junior Member
iTrader: (2)
Join Date: Aug 2006
Location: Louisville Kentucky
Posts: 222
Total Cats: 0
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
First off Find a machine shop that does good work! ![big grin](https://www.miataturbo.net/images/smilies/biggrin.gif)
http://www.importperformanceparts.net/
Pauter Rods=699...........one and a half week wait for them to get them
weisco pistons=439....shipped day after I ordered
Gaskets also
http://www.Summitracing.com
ARP head & Main studs=215 the mains are on back order had 9 day wait time on those (but they shipped really quick)
I have the hook up with a buddy for bearings, oil pump, and water pump....etc.
![big grin](https://www.miataturbo.net/images/smilies/biggrin.gif)
http://www.importperformanceparts.net/
Pauter Rods=699...........one and a half week wait for them to get them
weisco pistons=439....shipped day after I ordered
Gaskets also
http://www.Summitracing.com
ARP head & Main studs=215 the mains are on back order had 9 day wait time on those (but they shipped really quick)
I have the hook up with a buddy for bearings, oil pump, and water pump....etc.
Last edited by TwoScoopsofHooah; 03-27-2007 at 12:39 AM.
#11
Elite Member
iTrader: (5)
Join Date: Jul 2006
Location: Central California
Posts: 2,557
Total Cats: 5
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
If it was me I would have to make the decision if I wanted to keep it or not first, then decide what to do with the engine. Since it sounds like you want to sell the car, just do a teardown, check the clearances and whatnot, get the bores honed if you can, then get new bearings, headgasket, bearings, and oilpump. Put it all together with new gaskets and a fresh waterpump and you should be good to go for the bottom end.
For the head, it really depends on how much time or money you want to put into it. I chose time and it cost me well over 20 hours with a dremel and some various fittings, but i did a street port n polish, cc'd n polished the chambers, and generally smoothed things out a whole lot to prevent pre-detonation. As for the valves, I lapped them instead of getting them ground. Finally, and possibly most important of all, during the final assembly clean out the bores to get all the oil out of em and lubricate them with wd40 or another light oil. Numerous sources said that this method helps the rings seat a lot better than when there is oil all over the bore.
Finally, if you are even slightly uncomfortable about building an engine, buy the book "The Racing Engine Builders Handbook" and go through it, you will probably learn a thing or two. My engine compression tested 210 lbs -/+1 after 2k miles, so simply lapping the valves and honing the bore works pretty well if it is done right.
good luck,
ryan
edit: Ps, look up the FM method of breaking in a motor and do it. you will not be disappointed.
For the head, it really depends on how much time or money you want to put into it. I chose time and it cost me well over 20 hours with a dremel and some various fittings, but i did a street port n polish, cc'd n polished the chambers, and generally smoothed things out a whole lot to prevent pre-detonation. As for the valves, I lapped them instead of getting them ground. Finally, and possibly most important of all, during the final assembly clean out the bores to get all the oil out of em and lubricate them with wd40 or another light oil. Numerous sources said that this method helps the rings seat a lot better than when there is oil all over the bore.
Finally, if you are even slightly uncomfortable about building an engine, buy the book "The Racing Engine Builders Handbook" and go through it, you will probably learn a thing or two. My engine compression tested 210 lbs -/+1 after 2k miles, so simply lapping the valves and honing the bore works pretty well if it is done right.
good luck,
ryan
edit: Ps, look up the FM method of breaking in a motor and do it. you will not be disappointed.
Thread
Thread Starter
Forum
Replies
Last Post