Yup! I should have shown that step as well, but there are some caveats to that. If the valve is not completely sealing up top and the head is only turned to its side then the fluid will still pool at the bottom of valve giving you the idea that the valve is sealing properly. With the Prussian Blue method you will see any flaws and know exactly where the valve and seat aren't sealing.
Awesome video! There are other videos showing valve lapping and the person shall remain nameless but when they chucked up the stem of the valve in an electric drill directly with no flex and started spinning away I had to stop watching, lol. I have lapped valves just like you did with the hand lapping tool in an American engine and I just cringed when he did that. very helpful video! Thanks!
Thanks! It was a lot of fun making this video! I haven't seen that video, but I can imagine. In the next week or so I will have a video up where I will be installing this head on a '83 944. This afternoon I was contacted by a local 944 owner that broke his timing belt so I will be documenting the process of swapping this head onto it.
Excellent video! BUT-what about measuring valve spring installed height, and most crucially, resurfacing the head? I know it wasn't warped, but you still want to 'skim' it so that the head gasket has a good surface to seal against. And for the more paranoid builder (like me!), having it inspected for cracks, and pressure checked.
I shot a whole scene where I measured the valve heights but they were like new, so I thought I'd leave something for the next video. At the end I just showed my straight edge across the top of the valves to show how it turned out, but I'll probably run into some of these issues on the other head. As far as skimming the head goes, if you get all the old gasket material off and the head is straight there is no reason to skim it. That said, its up to you and skimming the head doesn't hurt, but again it isn't necessary. I often have a machine shop double-check my work and I've never had to skim a 944 head, which are all still going strong! I personally have never seen a 944 head with cracks. I work on all kinds of engines and its common for those to have crack which need pressure testing, but if you find cracks in a 944 N/A head then I would just replace it. I hope that helps and thanks! I'll be sure to bring all this up in my next video on heads!
Watching the lapping I wondered could you put compound on the valve then put your variable speed drill on the stem and slowly rotate valve forth and back ? I think it will work like a champ
The thing you have to watch out for is that you do not want to over work the valves or the seat. The proper method is to gently work the valve back and forth for about 30 seconds or until the compound isn't crunching anymore. If you continue to work beyond that or use a machine you could trash the valve margin, or ruin the valve seat. When this happens, the valve seat will need to be re-cut and the valve will need to be replaced. This is a fairly delicate process and only meant to improve the seal, not intended to remove any pitting. I hope that helps!
Great video. I'm refreshing the head on my '87 951 now. Thanks for posting. Quick question: I originally pulled the head because I found coolant in the oil and figured it was a head gasket failure. Any recommendations for further maintenance or things to check while I'm in here and is this cause the just pull then engine and rebuild now? Car currently runs great. ~130k miles.
Coolant in the oil and vice versa are more commonly caused by the oil cooler seals failing. Some claim that only the oil will push into the coolant since the oil pressure is higher but this is not always true. Depending on which seal fails on the oil cooler the coolant will get into the oil. When this happens you not only have to replace the oil cooler seals but your going to find the bottom end filled with muck that will require oil pan removal to get it all out. You also must replace the rod bearings since the acid in the coolant will eat them. See my videos on the 1984 red 944 that had this issue. Someone replaced the head gasket and of course since that wasn’t the issue it happened all again. So we went in and fixed it right and the car runs perfect now. So considering the circumstances you might be better off just rebuilding the engine. It will be much easier from someone who has been there and done that many times. I hope that help!
@@edredas I think that's the right call. I've almost got the engine out now, been about 15 hours trying to get exhaust bolts off. Can you remove the engine with the exhaust crossover pipe attached?
@@edredas I'm doing a refresh on the head of an '87 NA w/ 232k miles. Ever run into an issue were the valves can't be removed because of a small lip that has developed at the uppermost keeper ring on the valve? the ring is just big enough so the last centimeter or so of the valve won't go into the valve guide when trying to extract the valve.
I got it on ebay just to try out a new tool that I thought everyone could afford, but it isn't very strong. The best spring compressor I have ever used for this job was a MAC CF-17, and I think you can get them or something similar in the $50 range. The mac makes this job very simple. So, unfortunately I don't recommend that little red handled one or the one I rented for $90. Honestly, it wasn't any better. I hope that helps!
Hi Edredas, I have a Porsche 944 and two of the valve guides on the exhaust slipped out. I got replacements 13.08 but their a little small. Any recommendations
Are they too small, as in too loose to go back into the head or too small for the valve? Pelican parts has the correct guides. I think I paid around $5 for each of these. In either case you could probably take the head to a machine shop and they should fix you right up! It usually isn't very expensive. hope that helps!
I guess I'm just used to it. I don't like using harsh chemicals indoors and usually that cardboard gets soaked in them and covered in grease so I just toss it. It helps keep things a little cleaner. Not to mention, it gets hot inside especially when I have to cut the fans off and shut the doors for recording, so I just go outside where it's cooler and there's better lighting.
Thats cool, just an old guy with old bones just sayin. I really enjoy the workmanship that I see in your videos. You rank with the likes of; irina25661 & van svenson.
Thanks, I just try and have fun. I've been meaning to make some room for recording when I need lots of space but I figured a lot of people watching these videos are probably going to be working on their cars in their yards too. So I want them to be relateable to the guys trying to do this at home with inexpensive tools.
First, great video. I'm about to jump into a 944t head refresh and this helps. Also, do you have a procedure for replacing the valve guides yourself if they were out of spec? I've read the procedure in the FSM and it's fairly involved, especially since anything new is oversized and may need to be reamed to size. Seems like a thing better left to a machine shop.
Yeah, I would just have them replaced by a machine shop. I mean, its not a hard job and may make a video on this one day, but you will likely spend more on buying the tools then they would charge.
Hello Edras, What is your experience with porting the heads ?. Does it do anything for extra HP or better Torque ?. Or can we say its just a waste of time and heads ?.
I've only ported and polished one 944 head... it's in my head rebuild video. The car ran great afterwards but hard to say if the work made any difference since I didn't drive it beforehand. I will say I don't bother most of the time since the castings on these heads are very good and this was mainly done on heads that were poorly made from the past. Most of the time those heads were made in bulk and the ports came out much smaller and in rougher shape than desired. This is not an issue on these cars. I hope that helps!
Thank you for this video. I will be doing mine in the coming weeks
Easy way to check for bent valves , spray brake clean in the ports it will run under the valve if the seal is bad
Yup! I should have shown that step as well, but there are some caveats to that. If the valve is not completely sealing up top and the head is only turned to its side then the fluid will still pool at the bottom of valve giving you the idea that the valve is sealing properly. With the Prussian Blue method you will see any flaws and know exactly where the valve and seat aren't sealing.
Great job
Thanks! I made another video on the process and went into a little more detail and also gave some ideas on how to port and polish the head!
i wonder if a 928 twin cam head would fit on a 2.7 block?
Its possible I suppose!
Awesome video! There are other videos showing valve lapping and the person shall remain nameless but when they chucked up the stem of the valve in an electric drill directly with no flex and started spinning away I had to stop watching, lol. I have lapped valves just like you did with the hand lapping tool in an American engine and I just cringed when he did that. very helpful video! Thanks!
Thanks! It was a lot of fun making this video! I haven't seen that video, but I can imagine. In the next week or so I will have a video up where I will be installing this head on a '83 944. This afternoon I was contacted by a local 944 owner that broke his timing belt so I will be documenting the process of swapping this head onto it.
edredas Oh cool. I am looking forwqrd to it.
Excellent video! BUT-what about measuring valve spring installed height, and most crucially, resurfacing the head? I know it wasn't warped, but you still want to 'skim' it so that the head gasket has a good surface to seal against. And for the more paranoid builder (like me!), having it inspected for cracks, and pressure checked.
I shot a whole scene where I measured the valve heights but they were like new, so I thought I'd leave something for the next video. At the end I just showed my straight edge across the top of the valves to show how it turned out, but I'll probably run into some of these issues on the other head.
As far as skimming the head goes, if you get all the old gasket material off and the head is straight there is no reason to skim it. That said, its up to you and skimming the head doesn't hurt, but again it isn't necessary. I often have a machine shop double-check my work and I've never had to skim a 944 head, which are all still going strong!
I personally have never seen a 944 head with cracks. I work on all kinds of engines and its common for those to have crack which need pressure testing, but if you find cracks in a 944 N/A head then I would just replace it. I hope that helps and thanks! I'll be sure to bring all this up in my next video on heads!
Watching the lapping I wondered could you put compound on the valve then put your variable speed drill on the stem and slowly rotate valve forth and back ? I think it will work like a champ
The thing you have to watch out for is that you do not want to over work the valves or the seat. The proper method is to gently work the valve back and forth for about 30 seconds or until the compound isn't crunching anymore. If you continue to work beyond that or use a machine you could trash the valve margin, or ruin the valve seat. When this happens, the valve seat will need to be re-cut and the valve will need to be replaced. This is a fairly delicate process and only meant to improve the seal, not intended to remove any pitting. I hope that helps!
good job...good video. ..
Thanks!
Great video. I'm refreshing the head on my '87 951 now. Thanks for posting.
Quick question: I originally pulled the head because I found coolant in the oil and figured it was a head gasket failure. Any recommendations for further maintenance or things to check while I'm in here and is this cause the just pull then engine and rebuild now? Car currently runs great. ~130k miles.
Coolant in the oil and vice versa are more commonly caused by the oil cooler seals failing. Some claim that only the oil will push into the coolant since the oil pressure is higher but this is not always true. Depending on which seal fails on the oil cooler the coolant will get into the oil. When this happens you not only have to replace the oil cooler seals but your going to find the bottom end filled with muck that will require oil pan removal to get it all out. You also must replace the rod bearings since the acid in the coolant will eat them. See my videos on the 1984 red 944 that had this issue. Someone replaced the head gasket and of course since that wasn’t the issue it happened all again. So we went in and fixed it right and the car runs perfect now. So considering the circumstances you might be better off just rebuilding the engine. It will be much easier from someone who has been there and done that many times. I hope that help!
@@edredas I think that's the right call. I've almost got the engine out now, been about 15 hours trying to get exhaust bolts off. Can you remove the engine with the exhaust crossover pipe attached?
Robert Freitas yup should be able to. Good luck!
@@edredas I'm doing a refresh on the head of an '87 NA w/ 232k miles. Ever run into an issue were the valves can't be removed because of a small lip that has developed at the uppermost keeper ring on the valve? the ring is just big enough so the last centimeter or so of the valve won't go into the valve guide when trying to extract the valve.
@@robertdowns4890 Oh wow, can't say I've ever seen that... are you in the facebook group? I would like to see some pics.
Great video! What spring compressor did you use? Specifically the one with the red handle.
I got it on ebay just to try out a new tool that I thought everyone could afford, but it isn't very strong. The best spring compressor I have ever used for this job was a MAC CF-17, and I think you can get them or something similar in the $50 range. The mac makes this job very simple. So, unfortunately I don't recommend that little red handled one or the one I rented for $90. Honestly, it wasn't any better. I hope that helps!
Thank you.
Hi Edredas, I have a Porsche 944 and two of the valve guides on the exhaust slipped out. I got replacements 13.08 but their a little small. Any recommendations
Are they too small, as in too loose to go back into the head or too small for the valve? Pelican parts has the correct guides. I think I paid around $5 for each of these. In either case you could probably take the head to a machine shop and they should fix you right up! It usually isn't very expensive. hope that helps!
@@edredas thanks I'll check it out
very informative, why are you working on the ground?
I guess I'm just used to it. I don't like using harsh chemicals indoors and usually that cardboard gets soaked in them and covered in grease so I just toss it. It helps keep things a little cleaner. Not to mention, it gets hot inside especially when I have to cut the fans off and shut the doors for recording, so I just go outside where it's cooler and there's better lighting.
Thats cool, just an old guy with old bones just sayin. I really enjoy the workmanship that I see in your videos. You rank with the likes of; irina25661 & van svenson.
Thanks, I just try and have fun. I've been meaning to make some room for recording when I need lots of space but I figured a lot of people watching these videos are probably going to be working on their cars in their yards too. So I want them to be relateable to the guys trying to do this at home with inexpensive tools.
First, great video. I'm about to jump into a 944t head refresh and this helps.
Also, do you have a procedure for replacing the valve guides yourself if they were out of spec? I've read the procedure in the FSM and it's fairly involved, especially since anything new is oversized and may need to be reamed to size. Seems like a thing better left to a machine shop.
Yeah, I would just have them replaced by a machine shop. I mean, its not a hard job and may make a video on this one day, but you will likely spend more on buying the tools then they would charge.
Hello Edras, What is your experience with porting the heads ?. Does it do anything for extra HP or better Torque ?. Or can we say its just a waste of time and heads ?.
I've only ported and polished one 944 head... it's in my head rebuild video. The car ran great afterwards but hard to say if the work made any difference since I didn't drive it beforehand. I will say I don't bother most of the time since the castings on these heads are very good and this was mainly done on heads that were poorly made from the past. Most of the time those heads were made in bulk and the ports came out much smaller and in rougher shape than desired. This is not an issue on these cars. I hope that helps!