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Title: Can I please ask your opinion on the port job of my heads? Post by: Matt Tobias on February 06, 2013, 08:37:09 am Hi there, here are the heads I just picked up. They are 040 castings with new guides and new 40x35 valves with mild port work, the bowls/seats are blended nicely. I'm thinking they need a little more work above the guide, on the roof. What do you experienced guys think? This engine is going in a fully caged Baja with fiberglass front end and fenders. It will also be utilizing a 091 tranny with the 4.57 R/P and 30x9.5 tires. What I'm after is torque with a nice powerband.
Thanks in advance! here are my engine specs- 2276 stock rods dual springs Norris 330S cam- .495 lift with 1.4s and 246* at .050. 8.5:1 1.5" header 44 IDF's (http://i12.photobucket.com/albums/a246/tobiism/BAJA/IMAG1163_zps9e2fd966.jpg) (http://i12.photobucket.com/albums/a246/tobiism/BAJA/IMAG1162_zps6a1558a2.jpg) Title: Re: Can I please ask your opinion on the port job of my heads? Post by: Erlend / bug66 on February 06, 2013, 09:11:40 am Try to keep up the air speed! Nice, fast (not to big) ports produce good torque if the rest of the engine is up to it :)
Is that a little bump in the lower left port? Get some good angles on the valve seat. Title: Re: Can I please ask your opinion on the port job of my heads? Post by: Matt Tobias on February 06, 2013, 09:17:56 am Try to keep up the air speed! Nice, fast (not to big) ports produce good torque if the rest of the engine is up to it :) Is that a little bump in the lower left port? Get some good angles on the valve seat. Thanks, the bump is the underside of the spring perch. When I get the heads opened for 94's I'm going to have Competition Engineering check the valve job and do whatever is necessary. Title: Re: Can I please ask your opinion on the port job of my heads? Post by: Torben Alstrup on February 06, 2013, 09:27:17 am What is port inlet Dai ?
T Title: Re: Can I please ask your opinion on the port job of my heads? Post by: Matt Tobias on February 06, 2013, 09:35:43 am Hi T the inlet port is 31.75mm tall by 30mm wide. The exhaust port is 31.75mm.
Title: Re: Can I please ask your opinion on the port job of my heads? Post by: fish on February 06, 2013, 11:18:00 am inlet ports loog good, you could straighten out the intake charge and have the slight oval ports make a v in the direction of the spark plugs, don't take too much off the roof and do not touch the "bump" also keep a swirl to the port.
lets see the chamber and ex port. 2cents Title: Re: Can I please ask your opinion on the port job of my heads? Post by: Matt Tobias on February 06, 2013, 13:26:06 pm Thank for all the replies so far, I do appreciate it. Here is the exhaust port and the chamber, which is semi-hemi.
(http://i12.photobucket.com/albums/a246/tobiism/BAJA/IMAG1180_zps4fd15f5d.jpg) (http://i12.photobucket.com/albums/a246/tobiism/BAJA/IMAG1174_zpsaadf2ca7.jpg) I plan on modifying the semi-hemi into more of an open chamber, after being intrigued by the success Rick Mortensen and Joel Mohr have been having with open chamber heads. Here are Rick M's heads (http://i12.photobucket.com/albums/a246/tobiism/BAJA/FinishedCC_zps47bf923e.jpg) Title: Re: Can I please ask your opinion on the port job of my heads? Post by: modnrod on February 06, 2013, 13:47:50 pm I'm intrigued by the shape of your chamber opposite the plug, the way the shape curls in towards the valves, rather than jus a straight line across the bore.
These "040" castings, are they OEM from somewhere, aftermarket? I'm sure they're common, but I haven't seen them before, and they look interesting. Title: Re: Can I please ask your opinion on the port job of my heads? Post by: rick m on February 14, 2013, 14:56:35 pm Matt,
I will post the heads I am redoing for a friends bus motor. We are finishing up the head mods and case mods right now for better oiling. Went to the same open chamber design I did on my street heads. Rick M Title: Re: Can I please ask your opinion on the port job of my heads? Post by: Matt Tobias on February 18, 2013, 23:11:27 pm Matt, I will post the heads I am redoing for a friends bus motor. We are finishing up the head mods and case mods right now for better oiling. Went to the same open chamber design I did on my street heads. Rick M Thank you, I look forward to seeing those pics! |