Cleveland head porting

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Jul 16, 2003 | 08:41 PM

#16

Ecuri

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Joined: Jun 2003

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From: Houston/Hope BC

Cleveland head porting

I have no off idle complaints with the big valves in a 2V head and have noticed no reduction in low end power on my 400. This is with a 210 or so .500 RV cam. If there is any loss at all on the bottom it is more than made up in mid and top end, it is a HUGE improvement. You MUST install hardended seats on the exaust side. I did not do the intake side and consider it optional to do so, and so far, 25K miles, have had no problems, but it would be 'bulletproof" if you did them also.
Your seat surfaces will be moving well out from where they are now. A LOT of metal will go away and you won't know how far to go until the valves are fitted. The guys that did my valve job have some kind of radius cutting tool they used to cut the port out to the seat area. Inquire.

Jul 16, 2003 | 10:32 PM

#17

Torque1st

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Cleveland head porting

The reductions due to shrouding wont show unless you are using a dyno. Seat of the pants just won't do in this case.

Jul 17, 2003 | 09:32 AM

#18

Ecuri

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Joined: Jun 2003

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From: Houston/Hope BC

Cleveland head porting

Didn't mean to leave the impression with anyone I was disagreeing, Eric. What you said is well proven fact. In my limited experience, with this one configuration, however, it just seems to be practically nil and has certainly, IMO, made the engine more of a pleasure.

Jul 18, 2003 | 02:45 AM

#19

Torque1st

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Cleveland head porting

If you get these engines set up right they are GREAT engines. One of the things that helps me with these engines is that I have driven almost every year of production and saw what happened to them. The 71 models were responsive torque monsters but even the 72, with minimal changes, was a dog in comparison. That is why I started with 71 specs then made improvements from there. I just wonder what would have happened if they would have had a few more years of production b4 they had to smog them out... Or what they would have been like with 68 or 69 as the first year of production.