I was wondering if the 1.7 rockers were going to allow the valves to hit the stock pistons. I am pretty sure that the stock pistons have valve reliefs, but I don't know if they will work or not.
If it is the origional 89 enguine and has the origional pistons then it should be fine. With the stock cam I have heard of people running 1.7rr on 86's which did not have valve reliefs. You may have to use taller valve covers though. I have a like new set of chrome ones with 302 embossed in them CHEAP. PM if interested
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88 fox bird, 99 explorer p head enguine, intakes, 65mm tb, crower 15511, 1.7 RR, FRPP shorties. 88 GT SD comp. AOD,
SVO mustang 3.45 gear 7.5 rear disk brake axle. 98 GT front spindles and brakes 5 lug 16X8 gt rims. Explorer rear disk 31 spline 3.73 8.8 going in soon.
I am interested in the chrome valve covers if they are in good shape. Send me an email at troyer2265@natzero.net and I will get in touch with you as soon as I can. Thanks.
I have an 86 with flat top pistons, stock valve covers, and a stock cam. There is a baffle in the driver's side valve cover which you have to remove. It's held in by 2 screws. Only drawback is if you want to add a cam later. Remember that the 1.7 ratio increases lift more than whats listed on the cam sheet. All cams are based on 1.6 ratio.
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Sold:('86 GT Jalapeno Red 'vert, 200,000 miles Lots of Mods!!!!
2006 Mustang GT
C&L Racer, Eibach, SCT, CHE, CMCV Deletes, PRP, 4:10s on the way.
New toy:
1989 Mustang 2.3L Auto. 5.0 waiting in the garage...
the 1.7 rockers will work on your 89 without a problem(valve clearence is fine)as long as your running the stock cam.the valve covers on the 89 will not clear the rockers ,even if you remove the baffle from the pass side you will still have a clearence problem with the driver side.your looking at about a 10hp increase.
I am looking for valve covers that will clear the 1.7 rockers. Will the "tall" ford motorsport valve covers fit under the stock intake, or do I get "short" valve covers and find a 1/2" spacer?
The tall ones wont clear the stock intake . I had proform 1.7 rr's on mine and the stock valve covers worked fine . I did remove the baffle in the oil fill port though . Or like you said , you can use a spacer and tall valve covers .
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Never argue with an idiot. They will bring you down to their level and beat you with experience...
As for the comments about the 1.7's and cams, it depends on the lift of the cam, like for instance I'm running 1.7's with an E303 cam and have no problems. I belive clearance isnt an issue with the stock pistons untill your lift gets up near the 550 rangs.
Ok, guys, it's time for piston to valve clearance 101.
Max lift has nothing to do with clearance. If a cam clears with 1.6 rockers, it'll clear with 1.7s.
When either valve is at max lift, the piston is nowhere near tdc. Clearance issues occur when the piston is near tdc. When the piston is coming up the bore, it chases the exhaust valve closed and when it's going down the bore, the intake valve chases the piston. When the piston is near tdc, the valves are barely open.
The determining factors for clearance are duration and overlap. You need to be concerned with how long the valve is open, and how much the valve openings overlap. Simply put, more overlap typically means the valve openings occur closer to tdc.
The only time max lift is a concern is for the valve springs. Valve springs are rated for coil bind. This is when the valve spring is fully compressed and is a bad thing. The higher the valve lift, the more chance of coil bind. For example, a valve spring may be rated for coil bind at 1.2" with an installed height of 1.85". You typically want to stay at least .050" away from coil bind so the max valve lift you'd want to run in this situation would be 1.85" - 1.20" - .050" = .600".
I personally have never run 1.7s with stock springs but many people have w/o problems. How many miles are on the motor? Springs wear with time. If you've got a lot of miles on them (100,000+) I'd consider replacing them anyway.
I have 160,000 miles on it. I quess I should replace them. Do you think that I should just get stock replacements or should I get some aftermarket ones? Which ones do you recommened? One more question. Did you have to machine down the valve guides to make room for the extra lift of the 1.7s?
Can I install 1.7 Roller rocker arms on a stock engine ? 
