Its all about the planning.

[Neil Harvey]

Rebuilding an engine.

Its all about the planning.

The most important task in rebuilding and engine needs to be completed before you even remove the first nut or bolt.

What is the objective? What is my maximum budget and what are my performance requirements? Is the engine going to remain stock or is it going to tickle my back side some more?

Remember, most if not all air-cooled engines need a restoration not just rebuilding.

Take pen to paper and plan!! I cannot stress the importance of this!

To remove the engine from the car, do I have the room to do this safely. Can I leave the car in the same place while the engine is been rebuilt? Do I have all the right equipment? If not, what will this cost? Can I borrow it? Will I make a mess (yes), and be able to keep the workplace clean? What am I going to do with all the disposal oil and trash?

Once the engine is apart, what am I going to do myself, what am I going to send out to have done, etc. Getting a base line cost for any machine repairs ahead of time, the lead time to receive back, is very important. This is a huge part of the budget planning. Am I going to have the parts powder coated, CAD plated, painted etc.? All this needs to be decided before doing anything. These costs are well known as they are a common restoration upgrade.

If you have a magnesium engine case, plan on head stud inserts, oil by-pass mod, line bore, cylinder decks skimmed parallel, some thread repairs, and some additional cleaning. Plan on having to rebuild the heads, new guides, maybe seat inserts, broken Exhaust stud removal, new valve springs and some or all, new valves. Plan for the worse, hope for the best. Remember to include parts like, new Clutch assy, oil hoses, filters, fuel lines and maybe some electrical upgrades and or repairs. The Alternator may need rebuilding, at the vey least, checking, the wiring probably needs some repair work as well. A lot of this can be established by a close inspection before the engine is even removed.

What basic rebuilding parts and consumables will I need? Will I replace all the standard hardware and fasteners? I will need new bearing shells, timing chains, chain support rails etc. Where am I going to buy these from? Will I go cheap and buy from the aftermarket and risk buying out of spec parts or will I buy direct from Porsche agencies. My advice is to do both. Buy the most critical parts like bearing shells from the dealer and the less critical parts like chain guide rails from the aftermarket.

Get answers to all of this before you even start. Planning is so important. Make up a schedule of work to be done and in what order. I am going to remove the engine on day X. I will remove the gearbox and clean it on the same day. Another day I will disassemble the exhaust system and intake. I will inspect each part and note any repairs required and add these to my rebuild plan and make sure these are covered in my budget. Included in the preplanning should be, what can I do to help lower the outside labor costs?

Once I have the parts back and the assembly starts, do I know what I am doing? Do I understand how to measure the case main housing, can I measure bearing clearances, do I understand how to check the piston to valve clearances, do I understand how to time the cams? Now is the time to understand all of this. Too many “jump” into this with excitement about rebuilding their engines without any clue of what they are doing or about to embark on.

Now, the engine and gearbox are removed from the chassis, the disassembly part begins. What tools are required, and do I have all of the tools required? Can I store the gearbox somewhere? Do I have the correct engine stand? Do I have an area to store all the Intake, sheet metal, exhaust system? Do I have a clean work bench space?

Keep the workplace clean. Clean after yourself especially after removing the exhaust system and Intake. Keep the floor clean. Keep the tools clean. As you make a mess, clean it. You will feel so much better working in a clean environment. I have seen pictures of tools left lying over the floor, an oiling mess on the floor, such a toxic place to work. Keep it clean and clean as you go. Only have the tools required to perform each job out, clean and put them away as you finish each job.

Now you have the top end apart, inspect the parts. Now is the time to collate the schedule and budget you have made to see if you are under or above what you have planned for. Do as much cleaning as you can yourself and do it as you remove the parts. Storing clean parts is way easier than dirty oily parts. In your planned budget you will have some timeline on when you will send out parts for cleaning and any finishing.

The major parts now under inspection will be the Camshafts, rockers, and cylinder heads. Probably most DIY’s will send out the heads for repair. The camshafts should be carefully inspected now for pitting on the lobes. If they are to be reused, and in great shape, clean them, oil them and put away in a safe place. Do not drop them as they will break into two pieces very easily. Inspect the rocker arms for wear. The bushings will probably show wear, especially on the thrust side of the rocker arm. Do the rocker arm pads show signs of wear? How do the timing chain gears look? Often these shows signs of chain misalignment and needs replacing. Now is the time to check your budget for these parts or add to it. A running total will be easier to budget than a hefty unknown amount at the end.

You should know what camshaft you are going to replace your’ s with before starting this rebuild. This is part of the performance planning. Making sure your cam can either be reground with the new profile or you will be buying new billets.

Pack the heads ready for shipping. Inspect the cam housings for wear and plan on removing the oiling spray tubes for cleaning. Now you can turn the engine over and visually inspect the cylinder bores for wear and any damage. It’s a good idea to do this before you remove so you at least have an idea of what is ahead of you. Again, this can add to the budget, so now is the time to make additions. Removing the cylinders and pistons can now be done with careful attention not to damage or beak anything. Be patient here. Expect the pin clips to go into space, Use some eye protection here. Don’t worry about losing any clips, these will be replaced with new ones. Be careful not to break any Piston rings either. You want to know if they were broken before so any oil consumption issues can be confirmed.

[Neil Harvey]

Cont'd.

The bottom end of this engine is now in front of you. The rods are sticking out of the case. They can be removed now with care, or after the case is split. Its your choice. I suggest, if you can, to remove the rods while the case is together hanging on the engine stand. Undo the nuts and before you remove the nuts fully from the rod bolts, tap on the nut with a soft drift or use the socket push the caps off the beams. Remove the beam and carefully slide the cap around the crank pin and out. Now inspect the rod bearings. The two bearings to really take note of are the number two and number five rod bearings as these are the last to get oil. If they look great, you can almost be sure the main bearings are in great shape. No oiling issues to be concerned about within the engine case. You will be replacing the rod fasteners, so don’t be concerned about mixing any up.

Note here, before you measure or have the rods rebuilt, replace the fasteners that will be reused in the final assembly first. Do not measure or rebuild the rods with the old fasteners. Expect the rods to need repair. Magnaflux crack check, straight check, Pin bushing replaced, fasteners replaced, BE’s resized, CCL’s checked and rebalanced. It is also a good idea to plan in the costs to have them re shot peened.

A large part of the rebuild cost is in front of you. The Pistons and cylinders. The first parts to check are the cylinders. Any damage and or big scratches? Don’t worry about the cross hatching. If they visually look good, now is the time to measure the bores. I would expect them to have an amount of ovality and taper to them. If you are staying with the same bore size, these can be repaired. Just be careful who you send them to. A third-party parts house offers this service but unfortunately, they have no clue of the repair work required nor do they have clue about what finish is required etc. I have re done the specs for so many customers who were given poor replacements. I won’t name who they are, but just be careful and before you send them anything, ask them for the specs that your cylinders will be repaired to.

Some things to know about re plating cylinders. Typically, Nikasil or a derivative (silicon carbide) of this is used. This stuff is super hard. Its used as it’s wearing surface is very good. The rings cannot be chromed faced as you cannot run two super hard surfaces against one another. The break in period is often talked about. Bedding in the rings. This is so misunderstood with Nikasil coated cylinders.

Under a microscope, the surface will be full if high peaks and low valleys. The surface is extremely hard and does not wear, when compared to the ring faces that are a lot softer. So, when you have very rough surface finish, with lots of high peaks, you will wear away the ring faces and destroy the ring seal. Therefore, the surface finish must be of a certain number. The lower the number on most scales is a finer finish. The 3rd party company I have mentioned here have no clue on what the surface finish should be. So be careful. My advice is to ask an engine builder or the actual repair place for their advice, not a parts salesman.

You need to also check the cylinder heights to make sure they all match. If they don’, they can be equaled by removing some material off the base. Also, now is the time to decide on any sealing system to be performed. This should have been included in your preplanning.

Pistons. These are easy to inspect for wear; the skirts should be unmarked and show no signs of trash sliding down the sides. If they do, they need replacing. If they look good, the next is to clean them. Removing all the carbon and dirt will show any signs of valve contact or head contact. Expect the pin bosses to need some help. Probably removing the burr made when you removed the clips. The pistons once cleaned need to be measured to make sure they are within spec. If they have a lot of time on them, it’s a good idea to have them checked for hardness. They do go soft over time with all the heat cycles. Most of the time these are replaced with a larger bore version. Ring lands need to be checked for wear as these become larger over time and the side clearance of the ring is an important dimension to hold otherwise you will have ring control issues especially when the piston is not under load. Pins sometimes show wear, and these should be carefully inspected as well. If new pistons are to be use, they will come with new pins and clips.

I cannot stress enough about the pre rebuild planning. This is so important. If you know the budget you must spend, this will dictate what upgrades you will be able to do. The most important decisions are, to make sure you have the engine funds available to rebuild the engine back into good working condition. There is no point in buying all these fancy upgrades if you must compromise on the repair work. Starting on something without having an end plan will turn this engine into your most hated thing and you will wish you never started it.

Go slow and be deliberate about this. Enjoy the journey. It should be a labor of love. The result will give you so much enjoyment once it’s all back together and running in the car.

Next is the engine case. I will continue this another day. I will do my best to keep this going. Unfortunately, I have a company to run and many customer projects to look after. But this is something I feel is needed. I hope to dispel all the myths and fears many have about rebuilding these “simple” engines. They are one of the most uncomplicated engines you could rebuild.

In the assembly part of this I will share many shortcuts, checks and “how to’s”, to help quicken up the assembly process. I will go into what to ask for when sending out parts for repair and what to expect when you receive them back. What to look for and what important repairs you need to be concerned about. Just because they look clean and shiny, doesn’t make them ok. Most of these engines make less than 350 BHP. So, any slight change in spec can have a huge affect on the final performance. Always think of your engine as 6 individual engines all making the same performance. If your parts are hastily repaired to look good and you drop 5- 10 ft/lbs of torque per cylinder, overall you have lost upwards of 60 ft/lbs of torque, resulting in a drop in useable horsepower of approx. 77 BHP. It doesn’t take much.

Your engine does not make the same torque per cylinder now due to air flow differences, cylinder heat and friction. So, why make it worse by assuming the repairs are correct, a lack of understanding and poor choices.

Enjoy the journey. But remember, nothing will humble a man more than an engine or an angry wife!!

[Rich76_911s]

Thanks Neil for posting this.

[QueWhy]

As someone who is just starting the planning phase this is a big help and great information. I really appreciate guys like you, Steve and Henry for sharing your vast knowledge with the masses.

[Neil Harvey]

Glad this is useful.

The most important thing here is to make a plan and figure on a budget as best you can before you start, so you do get in over your head.

Remember, the heaviest part of the build is the disassembly, cleaning, measuring and costing. The machine reconditioning will typically be sent out and the assembly is a lot quicker. You will never know exactly what is required until you disassemble and inspect all of the parts.

When we receive an engine we have a standard receiving charge that is paid in full at the time of delivery. This covers the disassembly, all cleaning, crack checking, measuring and the estimate. As we have the engine fully part, thoroughly cleaned, crack checked etc, we know exactly what machine repair is required, (we do all machine repair work in house), what parts, any out side services needed and the assembly time. We can then give the customer a full quotation for the repair work, all parts and assembly, including any sales tax required.

We do our best to get to the machine work within days of receiving it so we can inform the customer of the work required and the costs. If you were to invest into some basic measuring equipment you can do this yourself and know before you ship the parts what is required.

Try to replicate this as best you can. It will make you rebuild a lot more enjoyable.

[QueWhy]

I started a thread looking for a spreadsheet with all the parts needed for a 3.0 rebuild and some members were generous enough to send me what they’ve used. So it’s nice to know I’m on the right path by meticulously planning everything.

I’m not sure exactly what direction I want to go with my rebuild and having the cost laid out as best I can beforehand will play a big factor in which path I chose. Option #1: some carb friendly pistons and cams with an eye on keeping cost down. Option #2: the Supertec 3,1 kit staying single plug keeping my SSI with M&K 2-1. Option #3: 3.2ss, twin plug, bigger exhaust, etc., etc.

[Wu.wei]

Awesome thread. Thank you for sharing your knowledge! Im sure you are a very busy man and for you to take the time you do to inform us speaks volumes. MAHALO

[mnak]

Originally Posted by Neil Harvey

Cont'd.

The bottom end of this engine is now in front of you. The rods are sticking out of the case. They can be removed now with care, or after the case is split. Its your choice. I suggest, if you can, to remove the rods while the case is together hanging on the engine stand. Undo the nuts and before you remove the nuts fully from the rod bolts, tap on the nut with a soft drift or use the socket push the caps off the beams. Remove the beam and carefully slide the cap around the crank pin and out. Now inspect the rod bearings. The two bearings to really take note of are the number two and number five rod bearings as these are the last to get oil. If they look great, you can almost be sure the main bearings are in great shape. No oiling issues to be concerned about within the engine case. You will be replacing the rod fasteners, so don’t be concerned about mixing any up.

Note here, before you measure or have the rods rebuilt, replace the fasteners that will be reused in the final assembly first. Do not measure or rebuild the rods with the old fasteners. Expect the rods to need repair. Magnaflux crack check, straight check, Pin bushing replaced, fasteners replaced, BE’s resized, CCL’s checked and rebalanced. It is also a good idea to plan in the costs to have them re shot peened.

A large part of the rebuild cost is in front of you. The Pistons and cylinders. The first parts to check are the cylinders. Any damage and or big scratches? Don’t worry about the cross hatching. If they visually look good, now is the time to measure the bores. I would expect them to have an amount of ovality and taper to them. If you are staying with the same bore size, these can be repaired. Just be careful who you send them to. A third-party parts house offers this service but unfortunately, they have no clue of the repair work required nor do they have clue about what finish is required etc. I have re done the specs for so many customers who were given poor replacements. I won’t name who they are, but just be careful and before you send them anything, ask them for the specs that your cylinders will be repaired to.

Some things to know about re plating cylinders. Typically, Nikasil or a derivative (silicon carbide) of this is used. This stuff is super hard. Its used as it’s wearing surface is very good. The rings cannot be chromed faced as you cannot run two super hard surfaces against one another. The break in period is often talked about. Bedding in the rings. This is so misunderstood with Nikasil coated cylinders.

Under a microscope, the surface will be full if high peaks and low valleys. The surface is extremely hard and does not wear, when compared to the ring faces that are a lot softer. So, when you have very rough surface finish, with lots of high peaks, you will wear away the ring faces and destroy the ring seal. Therefore, the surface finish must be of a certain number. The lower the number on most scales is a finer finish. The 3rd party company I have mentioned here have no clue on what the surface finish should be. So be careful. My advice is to ask an engine builder or the actual repair place for their advice, not a parts salesman.

You need to also check the cylinder heights to make sure they all match. If they don’, they can be equaled by removing some material off the base. Also, now is the time to decide on any sealing system to be performed. This should have been included in your preplanning.

Pistons. These are easy to inspect for wear; the skirts should be unmarked and show no signs of trash sliding down the sides. If they do, they need replacing. If they look good, the next is to clean them. Removing all the carbon and dirt will show any signs of valve contact or head contact. Expect the pin bosses to need some help. Probably removing the burr made when you removed the clips. The pistons once cleaned need to be measured to make sure they are within spec. If they have a lot of time on them, it’s a good idea to have them checked for hardness. They do go soft over time with all the heat cycles. Most of the time these are replaced with a larger bore version. Ring lands need to be checked for wear as these become larger over time and the side clearance of the ring is an important dimension to hold otherwise you will have ring control issues especially when the piston is not under load. Pins sometimes show wear, and these should be carefully inspected as well. If new pistons are to be use, they will come with new pins and clips.

I cannot stress enough about the pre rebuild planning. This is so important. If you know the budget you must spend, this will dictate what upgrades you will be able to do. The most important decisions are, to make sure you have the engine funds available to rebuild the engine back into good working condition. There is no point in buying all these fancy upgrades if you must compromise on the repair work. Starting on something without having an end plan will turn this engine into your most hated thing and you will wish you never started it.

Go slow and be deliberate about this. Enjoy the journey. It should be a labor of love. The result will give you so much enjoyment once it’s all back together and running in the car.

Next is the engine case. I will continue this another day. I will do my best to keep this going. Unfortunately, I have a company to run and many customer projects to look after. But this is something I feel is needed. I hope to dispel all the myths and fears many have about rebuilding these “simple” engines. They are one of the most uncomplicated engines you could rebuild.

In the assembly part of this I will share many shortcuts, checks and “how to’s”, to help quicken up the assembly process. I will go into what to ask for when sending out parts for repair and what to expect when you receive them back. What to look for and what important repairs you need to be concerned about. Just because they look clean and shiny, doesn’t make them ok. Most of these engines make less than 350 BHP. So, any slight change in spec can have a huge affect on the final performance. Always think of your engine as 6 individual engines all making the same performance. If your parts are hastily repaired to look good and you drop 5- 10 ft/lbs of torque per cylinder, overall you have lost upwards of 60 ft/lbs of torque, resulting in a drop in useable horsepower of approx. 77 BHP. It doesn’t take much.

Your engine does not make the same torque per cylinder now due to air flow differences, cylinder heat and friction. So, why make it worse by assuming the repairs are correct, a lack of understanding and poor choices.

Enjoy the journey. But remember, nothing will humble a man more than an engine or an angry wife!!

thanks neil for sharing this it is very informative.

[Toomanystars]

Awesome!

[Neil Harvey]

I owe something about the assembly. I'm behind in the office and the work is piling up. But with the current health situation I may have time really soon to continue.

Take care and stay safe.

nh

[gsxrken]

Originally Posted by Neil Harvey

I owe something about the assembly. I'm behind in the office and the work is piling up. But with the current health situation I may have time really soon to continue.

Take care and stay safe.

nh

Following along here as well. I’m staring at my long block on the p201 and need a plan.