987S Engine rebuild - Page 3 - 986 Forum - The Community for Porsche Boxster & Cayman Owners

I bougt a nice 987s with broken engine, and now im up to make a good overhaul at the engine The engine was in good shape with all service records stamped until the second owner bought it and went to a local "mechanic" (plumber), This plumber was supposed to repair a oil leak from the IMS shaft seal. He swapped the seal and somehow he put the camshafts out of timing... When he started the engine hi heard some crunch sound (two broken exhaust valves) so he pulled out the engine again for inspection but when it had it out, he succeed to drop the engine upside down like a toast with the marmalade down, crashing the intake manifolds. Then he realised he was in a problem and then he called me in to help him out, as he told me this story a just have to laugh and tell him that if this was my car i would have his balls chop off. So I helped and bought the car at a good price

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That's the funniest damn thing I've heard all week! Good fortunes for you sir! I can't wait to see how this goes. Sent from my SM-G970U1 using Tapatalk

Sweet looking 987!

As Porsche engines has very poor quality (told by the plumber mechanic) what was broken when he dropped the motor at the floor was this..

Just Imaginate the plumbers face when he turned the ignition key (with the camshaft out of timing) and hear how the pistons vas bending and breaking exhaust valves....

I’m a bit confused about how to measure the weight of the piston to be available to order a new unit! I have seen that there is two different piston models 466-472g and 460-466g. As you can see my piston weights 544g with rings, clip and pin. Am I’m wrong weighting the piston together with rings, clips and pin? Or is my old scale wrong??

I think that the piston weight is the piston by itself

Sorry my fault! didn’t read it well, the correct weights for new factory pistons is: A. 535-541g Ref 99610303215 B. 541-547g Ref 99610303216. As my pistons weights 544g they belong to the second group Ref 99610303216.

you may want to try to weigh it without the rings, clip, and pin. the rings and clip probably don't weigh much but ill bet removing the wrist pin is enough to drop you down a weight class

I found a nice looking used manifould at ebay at good price. I have ordered also new: Piston rings Gasket set Exhaust valves A reforced IMS Spark plugs Filters etc..

You may want to look at a 996 intake setup. It's an easy modification with the motor out. Used with the 3.2 airrbox and MAF housing won't make a difference, but pairing it with a 996 tune, 987 airrbox and 3.25" diameter MAF housing will. Sent from my SM-G970U1 using Tapatalk

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That’s sound interesting, What part from which car?

sorry, i should correct what i said. i keep forgetting that this is a 987 , not a 986, so you already have the larger airbox and MAF housing. so what you would need is the intake runner and larger TB. You would not need a new tune since your DME is already mapped to the larger MAF housing. heres the intake runner with plenum: https://www.ebay.com/itm/143989781053?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=143989781053&targetid=1263094005266&device=c&mktype=pla&googleloc=9014819&poi=&campaignid=13917615559&mkgroupid=128459919281&rlsatarget=pla-1263094005266&abcId=9300613&merchantid=101683722&gclid=Cj0KCQjw7MGJBhD-ARIsAMZ0eev2eRFC-V6wNTXswMrcO6qwabCsnFGCH4xgQeP0SFP5NH7UIQC3uQgaAue uEALw_wcB you sohuld be able to pair that to an 82mm TB. https://www.amazon.com/gp/product/B00BJJ9FP2/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 On the 986, there is a pretty big discrepancy between power outputs for the 3.2 and 3.4 motors, which with all else being equal is likely due to the much smaller intake and TB between the 986 and 996. The 987 airbox is much larger than the 986, and has a 3.25"MAF hosuing already, so you would just need a 78 or 82mm Bosch TB and the 996 intake plenum/runner.

But this is my first watercooled boxer six so this is new to me, But I suppose it´s also have to do with valve size and cylinder head intakes etc... What is the win? My engine will just have sport air filter, race exhaust manifolds and 200cell cats, nothing more at the moment. On the 986, there is a pretty big discrepancy between power outputs for the 3.2 and 3.4 motors, which with all else being equal is likely due to the much smaller intake and TB between the 986 and 996. The 987 airbox is much larger than the 986, and has a 3.25"MAF hosuing already, so you would just need a 78 or 82mm Bosch TB and the 996 intake plenum/runner.[/QUOTE]

In the 986/996 models, the 3.2 and 3.4 L have the same valve sizes. I don't think the valve sizes were increased on the 987 until they put the 3.4 in the cayman s, but I don't know that for sure.

I´m very interested about the intake manifolds as I have to substitute mine, What plug and play options existe to improve the 987s manifolds (lowcost..)?

What size is the TB and plenum legs (to each bank manifold) on the 987 intake plenum? And is your goal to have an OEM type package or are you gonna go renegade? If it were my build and I were sticking with OEM, I would use a 987 airbx, 3.5" intake tubing, 78mm or 82mm TB connected to a plenum that is 3.25 or 3.5" in diameter. A new Bosch 82mm TB cost me about$200 a year ago. The 996 plenums are 3.5" but are a straight T shape instead of the curved T. If you find an old DBW model they can be had for $25. For the intake tubing (from airbox to plenum) I would do it custom with silicone and aluminum to eliminate the resonator and reduce heat soak from the engine bay. That is as large as you can go physically given the space constraints and should be plenty for the engine and be will only cost$100 love you have all the angles figured out. If you wanna go renegade, cut a hole into the trunk and do a short ram intake. Theyre loud, and lots of fun Sent from my SM-G970U1 using Tapatalk

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I haven’t told but I’m good making composite parts for racing cars, therefor I’m considering making my own intake manifolds, just for some small hp gain and good looking (done it before). I believe the easiest is just using de oem units making the with more capacity and ready to fit together with 996/997 items. So the question is what parts to fit making a nice driving road car prepared for track days and fun?

What’s the differences between 996 and 986/987 3.2L intakes diameter?

I've never laid hands on the 996 manifolds, but my understanding is that the piping is the same diameter but the legs are longer and makes the manifold sit up higher. If you have the capability, you may be able to reproduce an x51 intake. There were different versions for the 996 and 997 cars. The 996 isnt markedly different from stock but does have wider legs that go from the manifold down to the valve cover. The 997 x51 is a totally difference animal altogether.

Still much to come, but I just received first parts last Saturday,

have you measured the cylinders for ovality and taper? It looks like you intend to reuse the 5 cylinders and add one new piston?

As you understand I’m gone need a other set of intake manifolds, As the used market is full of good units I will look there, Here comes the question! which one is the best (cheap) if I’m looking for some more power??? 986/987, 3.2 987, 3.4 911, 3.6 etc..... Im playing with the idea using the units I purchase (cutting and 3d scaning them) to make my own version in composite.

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Yes, I left this to a local machinshop who take care of this,

I always use to weight the pistons before i assemble them to the engine, The new piston arrived weighting 540g and when I put the old units at the scale the weighted 543g.... But after cleaning carbon the made the same 540g as the new unit. So 3g carbon weight at each piston..mmmm

Was that with the wrist pin? Sent from my SM-G970U1 using Tapatalk

I went to the machine shop picing up the cylinder heads today, The damage one with new valve guides, Valve seats and with six new exhaust valves,

I`m rebuilding this engine just to have something fun to use until i finish a more powerful unit for this car. As I didn’t unassembled the engine and it’s no way for me to know if there any lost parts, bolts etc. I will just put everything together first before I glue it together with gaskets and Loctite, I will handle over the cylinder block tomorrow to the machine shop to make the IMS hole bigger using a CNC milling machine. This way I can change the IMS ballbearing everythime I change clutch. At the lefthand side you have the improved IMS and at the righthand side the OEM unit, increasing diameter at the engine block IMS hole to 62mm it will be no problem changing this in the future...

I sent the engine block to mechanise milling IMS hole opening it up to take the new 62mm IMS. It`s looks great! Under my point of view I don’t see milling the whole with the engine in place at the car as several companies sell, perform or rent, As I see it no matter how careful you are it will always come in a lot off metal shavings in the engine who will go around whole oil cirquit damaging the engine.

At the final I haven’t changed nothing from stock parts rebuilding the engine, I have just rebuilt the with the idea of build an second more hot engine making a coming swap in the future. As I had everything just mixed up in boxes it’s been like puzzle, driving me crazy.. Nothing was marked as it should have been etc… But now engine is together and finished but with one little shaft left over ho I can’t find out from where it comes or goes, this driving me crazy! If anyone knows anything about this shaft please help!

Photos of the little shaft/axle

Some pics putting together the engine, at the last pics you have a hint why of my nickname

The engine is now finished excepto for one berating hose that’s on its way by post

Nice progress. Where did the shaft go? Sent from my SM-G970U1 using Tapatalk

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I still haven’t no idea where this bloody shaft goes, as I they gave me the engine totally unassembled in boxes 📦 there is a possibility the shaft not from this engine, the thing is, this kind of engines I divided in two identical half’s, why just one shaft? This is getting me a bit on my nerves…… I now have the engine finished except for one breathing hose who still haven’t arrived. Shaft Shaft Shaft

Very nice work. For a decent skilled DIY, with access to some general tools, but nothing Porsche propriety specialty tools - how hard would it be to do IMS or even engine rebuild? I had done engines rebuilds, but that was much smaller units or much simpler. The smallest was a 650 cc in Fiat 126p, the largest was 3.8 V6 Pontiac Bonneville. So yeah - is it doable or one must have very special tools?

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The only special tool you absolutely must have is the one to put on the piston rod and locking clip

I had the engine in (not the easiest thing, I have to admit!) finally, I test started it up for about 10sec and everything sound ok (I believe), This was just a short test without any cooling liquid, exhaust, driving shafts, AC plumping etc connected. As I now news it do start, I will connect all the rest tomorrow afternoon!

Congtratulations, you are in the home stretch now!

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My old back are completely destroyed after pulling in the engine…. But what a great feeling!!!!!

Fantastic work!