dburgessc

Sorry, I was not trying to offend you with my post. Just like talking about Z's is all. Kind of curious myself about how much HP is gained from just a port and polish. Anyone out there been dyno tested before and after porting?? Don.

People seem to forget at times its not the increase in HP and Torque you get from any one procedure, its the increase you get from many small things that are carefully planned out and balanced with one another. When flow through engine is right and carburetion mixture is stachiometric through your engines RPM range, ignition is strong and timing is correct, proper selection of cam profile and valve size are made as well as a good cylinder head choice are made, the list could go on and on. Power and performance are a carefully balanced mix of many things working together in harmony but I better go now before I get too Zen about this and start chanting! ha ha. Anyway my point is: Yes, porting and polishing will help and will increase horsepower but how much of a contribution it makes or whether it is worth the time and effort of doing it are very debatable. However I absolutely love working on my car and would never consider time spent improving it a waste. Talk to you all later! Don.

Went down to that Z specialty shop again to see about buying the gasket kit I was talking about. The name of the shop is "Z Sport" in Everett, WA. 1-800-633-3308. The brand name of the gasket kit is "Ishino". They wanted $160 for it but I found the same kit at "Autopartswarehouse.com" online for about $80 and bought it there. No charge on shipping orders over $50. Much higher quality gaskets that fit right and will allow me to finish match porting my engine. On another note when I was talking to the owner of the shop and telling him what I was doing to my car with the porting and polishing he surprised me by saying I was wasting my time doing this as there was not much to be gained by trying to improve the flow of air through my engine. I was fairly flabbergasted to hear this from someone who claimed to have much experience racing Z cars. He didn't even believe in a 3-angle valve job. I have always believed that improving flow as well as larger valves, better cam, better ignition, better exhaust flow, better carburetion are the only ways to truly coax horsepower out of any type of engine. Many reputable books as well as a lot of posts from other members here seem to confirm this to me as well. Call me "old school" but I will always take this approach when building engines. Too many people these days will just buy a stock car put a new muffler on to get a fast sound, stick a bunch of plastic trim on it and maybe put nitrous on it to get push button power that will probably melt down an engine that was never designed to withstand these stresses in the first place. Anyway I would love to hear the opinions of others at this club about this, especially those who have real hands on experience building engines. Till next time, Don.

Just a little followup with this post... I just found a shop where I live now that is a Z-car specialist shop. The guy I spoke to there told me that Fel-Pro gaskets while good for domestic vehicles are absolute junk for imports with nothing ever lining up very well. He showed me a intake gasket that he had there from an import manufacturer (Sorry but I forgot the brand name) and it was like a night and day difference from the Fel-Pro gasket. Complete different construction and very high quality! Needless to say this will be the gasket set that I will purchase to do my engine and the gasket that I will use to match port my intake to my cylinder head. When I get the brand name I will make another post and pass this info along to all. Thanks again for the responses to my post. Don.

Got a quick question for anyone who has rebuilt SU carbs. Does anyone sell the bushings for the throttle rod that runs through these carbs and is notorious for leaking air into the carb affecting mixture? I know ZTherapy replaces these bushings with a sealed roller bearing when they rebuild a SU but I was hoping that maybe someone has replaced these stock replacement bushings and could provide me with a little insight. Thanks, Don.

Great informational link, Thanks! but also wanted to hear from anyone who has gone through the process so I can learn before I do it the hard way and ruin a head that I have much invested in. Any other engine builders out there?? Also the head I am using is the E-31 with the larger 280Z valves. I have eyebrowed the edges of the cylinders for valve clearance and will test for sufficient clearance using plastiguage but if anyone knows of additional articles, notes, commentary or photos from anyone else who has performed these mods I would love to see them just to make absolutely sure I am not overlooking anything i might regret later. Thanks again, Don.

Hello fellow Z-car enthusiasts, I am in the process of doing numerous performance upgrades to my 240Z. Currently I am getting ready to match port my intake to my head and port and polish all the runners of both the head and intake. The problem I am confronting is that the intake and the head ports as of right now are almost a perfect match. I could simply get away with cleaning away the casting flash and smoothing the bores for better flow. However the intake manifold gasket (Fel-Pro) does not match the ports on the head very well. It is misaligned slightly in opposite directions on each end of the head. If I shift the gasket to the right to better align the ports on the right then the left is aligned even worse and vice-versa. Seems a shame to grind already matching ports on head and intake to align to the gasket. Just wondering if anyone else has run into this problem and to know what you did to resolve it. Also if anyone knows of any really good articles online about match porting or just on porting and polishing in general I would sure like to read them. Thanks for the help! Don.