Reply With QuoteHardened seats are for unleaded fuel.I myself dont have them but run leaed fuel or use a lead additive.A regular head job will not make a big noticible difference unless they were really bad.A port job will.
I am going to take my heads down to have a valve job done and I need to know what to ask for. I ask people and everyone has an opinion just like a$$holes. I need to know from "boat guys" not car guys. I was quoted $385 w/ hardened seats.The guy said I need to put hardened seats in because the heads are older. The heads are oval port from my 396 high performance bbc.The valves are very large.I am putting them on my 454 w/ 9:5:1 compression. I just want the right stuff on my engine.Also will I get more horespower/tork with a good head job? I am still learning so any advice will help alot.
Hardened seats are for unleaded fuel.I myself dont have them but run leaed fuel or use a lead additive.A regular head job will not make a big noticible difference unless they were really bad.A port job will.
I am going to take my heads down to have a valve job done and I need to know what to ask for. I ask people and everyone has an opinion.
I Was Thinking About this question you have asked There Spitter DUDe and I have the Answer for you and a Pic I think that this is what to ask for when you need to get a Valve JoB Done to Both HeaDS and you have to get them Done By some one who knows what they are Doing and How to Finish them also you might ask about the Three angle Job it has allot better or Cleaner Release of the Pressure any way take care see ya later and Hope this helps make your day
Keep it WET
http://pstr-m05.ygpweb.aol.com/data/...9E21L900C8.jpg
They will last a LOT longer with hard seats, the extra load that marine engines run under will recess old "soft" seats in short order. As long as your having seats installed, increase the valve size to the 1.88 valves. And if you have any money left I would go with the 2.19 intake also. A good 3 angle valve job and pockett port will really help the heads alot. I have the 67 closed chamber 396 heads on my 468 with big valves and porting and it turns an A impeller at 5300 rpm, which = around 440hp, and that is through logs and slip in mufflers.
I asked about porting and 2 people told me that it wouldnt make a difference. What would be my gain by porting?I am definately getting a 3 angle job done.I just need to know what else to get done.
Originally posted by 396_WAYS_TO_SPIT:
I asked about porting and 2 people told me that it wouldnt make a difference. What would be my gain by porting?I am definately getting a 3 angle job done.I just need to know what else to get done.If you arre running a larger cam and carburater the porting will bring theses things to life for a stock motor there will be less gain.If porting didnt make much difference why are race motors ported?Answer needed to take advantage of larger cams,and other intake mods.
If someone told you porting does not help performance, they dont how to port or dont know what they are talking about. A mild bowl job will will improve performance from idle all the way up to what ever you rev it to. Typical gains on a large V8 are 15 to25 hp on a stock motor and much as 40 and more on highly modified engine. If you are good with a grinder and know where to grind, it is one of the few "free" hp upgrades out there.
I was running a 455 pontiac with all the bolt ons at 12.60s. Pulled the heads and ported them and dropped ET into the high 11s.
It works.
Anybody heard of a 5 angle valve grind? I'm getting some heads back real soon that are suppose to have this "trick" grind. I also opened em up to the 2.19 in. & 1.88 ex. This machinist also said up 50hp gain depending on how radical the engine is. BTW nice pic big daddy!
You can do as many angles as you want to dress the stones for. The more angles, the smoother the "turn" is as the air flow turns the corner from the port to the chamber. We even have a radius cutter that machines the 45* seat angle with a rounded smooth radius rather than defined sharp edged angles. In most cases a 5,6,7 or more angle is slightly better for flow than a 3, but it is one of those diminishing return things-- the extra work/expense increases with very little return in improved power for the extra effort. If you are going to get extreme, spend the money for some good aftermarket heads. You will get more bang for your buck that way. But a properly done pockett port/3 angle is inexpensive and will really wake up a stock set of heads.
More angles=better low lift flow. Porting does help ALOT! $385 w/hardened seats sounds reasonable as long as they do a good seat grind. Just ask for a 3 angle seat and a 30 deg back cut on the valves. You want to port them before you get the valve job done.
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