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Cam Timing question for the experts on Isky 1007B I am building an 8BA with 286 Scat stroker kit. I have the bottom end done. The cam and valve train is all installed and lashed and as I was checking cam timing I find that the ISKY 1007B timing does not match up to the specs on the card. They are about 7-9 degrees retarded from the spec sheet on the valve opening points? (This is on the Intake I didn’t check the exhaust side yet) the card shows Int opening @.020 to be 17 BTDC its actually 7.5*. The @ .050 card numbers should be 7* BTDC and its actually at TDC (7* retarded) the closings numbers on the card are @ .020 59* ABDC and its 58* and by the card @.050 should be 49*ABDC and its actually 48* so the closing points are only off 1 degree. The centerline on the card shows 111 I’m getting 115.5 (by the opening/closing method) and 114 (max lift method) I’m pretty bummed and don’t know what I should do? I’ve never had a cam be off by this much before. Any suggestions or ideas? Thanks in advance. Mike
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Re: Cam Timing question for the experts on Isky 1007B Are you checking with the valves in and assembled?
The specs are taken from a lifter with no valve installed.You are out because the lash has to be taken up before you get valve movement. Do it without valve direct from lifter. |
Re: Cam Timing question for the experts on Isky 1007B X 2
Jim |
Re: Cam Timing question for the experts on Isky 1007B I am checking from the valve but with ZERO lash on that valve
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Re: Cam Timing question for the experts on Isky 1007B Is this a regrind or an original Isky cam? Is it marked 1007B?
Jim |
Re: Cam Timing question for the experts on Isky 1007B 4 Attachment(s)
Brand new ISKY 1007B $315.00 from Reds Headers.
Pic #2 shows where intake centerline is 114* should be 111*. Pic#3 shows TDC and timing gear marks lined up correctly. Pic #4 shows dial indicator at .050 for opening reading off by 7*(retarded). |
Re: Cam Timing question for the experts on Isky 1007B Did you locate tdc with positive stop method? Not just with dots lined up.and dial gauge
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Re: Cam Timing question for the experts on Isky 1007B I was thinking the same thing.
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Re: Cam Timing question for the experts on Isky 1007B Yes,checked and rechecked. TDC on the wheel is acurate. If the degree wheel was off the closing event would be off by the same amount as the opening event as with the centerline but the closing event is only off by 1* the centerline by 3-5 degrees depending on the method and the opening about 7-10*. Im fairly certain the cam is ground wrong or maybe the card is wrong but I dont think the card is.
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Re: Cam Timing question for the experts on Isky 1007B I know it's a pain, but you may as well return it. If it was me, I'd talk to Pete. He posts here. He did my Potvin 425 and it's dead nuts.
Jim |
Re: Cam Timing question for the experts on Isky 1007B Pete recommended this cam thats why I bought it. Im hoping he chimes in. Maybe I can get away advancing it some, but thats still a bunch of BS. I would maybe expect that from a cheaper cam but ISKY???? Words cannot describe the level of pissed I am right now!
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Re: Cam Timing question for the experts on Isky 1007B Time to talk to Red's
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Re: Cam Timing question for the experts on Isky 1007B You cannot check cam timing without the timing cover in place and camshaft end-play properly controlled. Any forward-rearward movement of the cam alters timing as a result of gear tooth angle.
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Re: Cam Timing question for the experts on Isky 1007B Very true. I made up a tab to hold the cam in place during the degreeing process.
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Re: Cam Timing question for the experts on Isky 1007B JWL thanks for the reply I will try it with the cover. I thought that might be the case but each time I checked timing events I made sure the cam was pushed back while I stopped at the measuring point but it really wasn't try to move out the front. I will try it with the cover on and post the results. I sure hope that's what it is but I'm pretty sure it's going to be the same result.
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Re: Cam Timing question for the experts on Isky 1007B I hear that there are some isues with the SCAT cranks ( machineing problems) ...could be in the keyway on the crank snout is off...Just a thought
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Re: Cam Timing question for the experts on Isky 1007B Quote:
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Re: Cam Timing question for the experts on Isky 1007B And talk to Jim at Reds
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Re: Cam Timing question for the experts on Isky 1007B Quote:
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Re: Cam Timing question for the experts on Isky 1007B 3 Attachment(s)
I tried it with the front cover on. Re verified TDC with piston stop, re zero'd Dial indicator and at .050 of valve lift (with zero lash) without the cover i got 0* or TDC with the cover and after resetting everything, it is actually 1/2* ATDC which is basically the same reading but it did slightly change 1/2* and is even further retarded from what it should be. The 3rd pic shows where it should be.
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