Guest sball Posted August 25, 2002 Share Posted August 25, 2002 I was told by a guy who has worked datsun motors for years that most Nissan heads will only flow 195 - 200 hp to get to 240+hp the main benefits are achieved by doing most work around the valve area, He also wants about $1000 to do so, apart from having valves seated well is it merely a matter of just a polish of the chambers etc or are there certain areas in the passage that need openining up ? Welcome any feed back from people with right experience. Quote Link to comment Share on other sites More sharing options...
yo2001 Posted August 25, 2002 Share Posted August 25, 2002 I guess you are talking about unshrouding the valves. That's a good place to work on. but you can go over more than the bore of the head gasket. So you need to becareful there. Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted August 27, 2002 Share Posted August 27, 2002 Are you sure the guy is reputable would be the first question I would ask. There is a lot you can do, but as Yo2001 said, you are limited by the diameter od the head gasket. Seems to me I recall there being a 91 mm one rather than the 89 stock, but I would need some help there. Basically you want to make sure there are no sharp edges in the combustion chamber. You can port match the intake and intake ports to the gasket, but I would leave the actual port work to someone with flow bench. If your man doesn't have a flow bench, move on. You can also blend in the area under the valve seat and make sure it is smooth. I would be really concerned about keeping my flow the same on all cylinders, which is why the flow bench is so important. Good luck. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.