ChickenGrease92 Posted October 16, 2020 Report Share Posted October 16, 2020 Hello everybody, So im new here and had a few questions about a head i just recently got at a pick a part. So my plans are to port and polish and slap it on my A15 im rebuilding. Its the h72 head and also has the #107 mark Is this head a good head for the a15 block? What are some good tips on porting it? Lastly, i would like to know if i can shave down the valve seat guides? Im open to ideas lmk Quote Link to comment
datzenmike Posted October 16, 2020 Report Share Posted October 16, 2020 I think you want oval intake ports and closed chamber heads. But I'll leave that for someone else. Which ever head you decide to use, yes the valve guide can be trimmed to make them aerodynamic you can also cut them off flush with the port. Myself I wouldn't cut them off unless a total race engine. Smooth where the bottom of the valve seats meet the aluminum head. No sharp edges or lip. Grind away any casting flash. Does not have to be mirror smooth. I like to gasket match the head and the manifolds as the openings are never a perfect match because of core shifting during the foundry process. Paint around all the ports with machinist's bluing. Center the new manifold gasket on the studs and then scratch the outline of all the ports with a scribe. Alternately you can just spray paint them. Remove the gasket and anything with paint can be ground away. Blend into the port walls and smooth as far as you can reach. Now do the same with both manifolds. When bolted together, intake and exhaust ports will align perfectly without any lips, are smoother and larger. Quote Link to comment
ChickenGrease92 Posted October 16, 2020 Author Report Share Posted October 16, 2020 Would it be a bad idea to cut the valve guides flush with the port? (the engine is going in my daily) so its not a race engine.... not yet lol Thanks for the reply mike Quote Link to comment
datzenmike Posted October 16, 2020 Report Share Posted October 16, 2020 The guide supports the valve along it's length and they do wear. I think for stock application, good oil control and longevity I would leave them and just trim the sides to make more aerodynamic. If a race engine they would be replaced on a regular basis Quote Link to comment
ChickenGrease92 Posted October 16, 2020 Author Report Share Posted October 16, 2020 Your right, i can see alot of things being replaced regularly on a race engine. Ill jus leave them alone and ill shave the bowl area down to get it smooth/aerodynamic. Thanks mike Quote Link to comment
ChickenGrease92 Posted October 18, 2020 Author Report Share Posted October 18, 2020 How do i post a pic on here? Cause On the exhaust port there is a. Air passage that i think goes thru the whole head and has a hole near the water outlet. Can i just put a plug on the water outlet assembly and call it a day? Quote Link to comment
afracer Posted October 19, 2020 Report Share Posted October 19, 2020 You might try finding a different head, there's much better options out there than the air pump/smog head. Quote Link to comment
ChickenGrease92 Posted October 19, 2020 Author Report Share Posted October 19, 2020 Im in cali and its hard to come across parts in my area. A Series stuff is super rare.. Could i tap the holes in the exhaust ports and maybe put a bolt in them? Or jb weld them? I dont want to run this h72 head for long, i want to swap it out of my daily, remove the h89 head and rebuild it and put it back in. I jus wanted to have a spare head so i can still drive my car to work Quote Link to comment
datzenmike Posted October 19, 2020 Report Share Posted October 19, 2020 Just disable the smog pump. How hard is that? Quote Link to comment
ChickenGrease92 Posted October 20, 2020 Author Report Share Posted October 20, 2020 I dont have any smog equipment, the car came like that when i bought it, and the parts that it did have were broken/incomplete.. so it will run fine with the exhaust passages plugged? Quote Link to comment
datzenmike Posted October 20, 2020 Report Share Posted October 20, 2020 If it's running now or was running just leave it. Like you said the air pump connected near the thermostat. If that's sealed so it doesn't leak, that's good enough. Why make it more work. Quote Link to comment
ChickenGrease92 Posted October 20, 2020 Author Report Share Posted October 20, 2020 Sorry i might of not been clear enough. I never ran this h72 head before. My engine has the h89 head. I would like to remove the h89(to rebuild it) and swap it with the h72, but i dont want to have idle or running issues. Thats why i came here asking my dumb questions.. Quote Link to comment
datzenmike Posted October 20, 2020 Report Share Posted October 20, 2020 It's not a dumb question. I'm assuming these ports are for air injection? If so, this is in the exhaust port and will in no way affect the running. Like having a hole in the muffler Quote Link to comment
ChickenGrease92 Posted October 20, 2020 Author Report Share Posted October 20, 2020 Yes those air injection ports all connect to each other, thats why i was thinking it may cause an issue. So ill go ahead and install it once my head gasket comes in.. Quote Link to comment
datzenmike Posted October 20, 2020 Report Share Posted October 20, 2020 Long as the exhaust can't get out. Bock off the cold end. Quote Link to comment
ChickenGrease92 Posted October 27, 2020 Author Report Share Posted October 27, 2020 So i ran the head and it runs good! No issues what so ever. I did find out my brake booster hose was cracked and that was probably why i had a weird idle from time to time. Replaced it and shes all good! Cheers! Quote Link to comment
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