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1989 f250 351 efi

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Old Feb 8, 2012 | 03:42 PM
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1989 f250 351 efi

Im on this site to get answers for my friend. He is getting a new cam for his truck. It's a comp cam CCA 35-255-5. His truck takes forever to gain speed and it doesn't seem to perform like a 5.8l should. Obviously timing a stuff would be reset so do you guys think this cam will " revive" this engine and make it pickup speed like it should. He got new lifters and springs with the cam also. Idk anything about this truck other than reading stuff on here so if I said anything wrong, forgive me lol


Thanks,

Trey
 
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Old Feb 8, 2012 | 04:47 PM
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It might help, but if its not running right now, that might not fix it. Where is the timing set at?
 
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Old Feb 8, 2012 | 06:27 PM
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I have no idea. I'm sure timing is off by alot. This was his dads truck. His dad bought it brand new in 89 and was passed down to my friend. I'm just trying to figure out some things for him.
 
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Old Feb 8, 2012 | 06:46 PM
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ok if it was me. I'd check the timing. Timing is supposed to be at 10* BTDC. Also ask if the timing chain has been replaced, if not, it might have alot of slack.

If the timing is off (less than 10*), or has alot of slack, the cam will be behind the crank. So the engine will be down on power.
 
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Old Feb 8, 2012 | 07:33 PM
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Will the timing still need to be 10 degrees btdc with that new cam. I read it was an aggressive cam.
 
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Old Feb 8, 2012 | 07:43 PM
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I am not sure, but I would imagine so. Your changing the cam, not the crank, and the timing is based on the crank. 10* before the #1 piston reaches top dead center.

I looked the cam up, its not a real aggressive cam from what I can tell. I have a 351w and I plan to run a Crane 444232 cam and 1.7 rockers. The Comp Cam he is looking at is more aggressive than the Crane.

Keep in mine that the SD EFI system CAN NOT handle any cam with less than 114* lobe separation, and when you add any kind of cam you will need a tuner to make the engine run properly.
 
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Old Feb 8, 2012 | 07:48 PM
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I plan to build a mild 351w, and I am sticking with the SD. For me I plan on Edelbrock Truck 5.8 EFI intake, Ford Racing GT-40 turbo swirl aluminum heads, Crane 444232 cam and 1.7 rockers, shorty headers, and of course a tuner for my EEC.

A MAF conversion can be done, then he can pretty much any kinda of head/intake/cam combo he wants.
 
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Old Feb 8, 2012 | 07:48 PM
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So this cam work on this engine without tune?
 
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Old Feb 8, 2012 | 07:49 PM
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It should. Because it has 114* lobe separation. But just keep in mind that a tuner might be needed. Especially if he plans on bigger heads and intake.
 
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Old Feb 8, 2012 | 07:52 PM
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Well the truck isn't running right now. He is just getting it running back how it was 3 months ago. Except I still think the timing was off or something cause it shouldn't take that long for it to get up to speed. He isn't looking at rebuilding it fully or anything.to much money
 
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Old Feb 8, 2012 | 07:59 PM
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ok. Well have him, or whomever might be helping. Check the timing, (don't forget to take the spout out), check spark plug fire (make sure its good a strong), check fuel pressure.

The 351w has 210 hp and 325 fpt. He should be able to squall the tires with no problem.
 
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Old Feb 8, 2012 | 08:05 PM
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Ok. Thanks for all your help. Hoping this all works out for him. Spent a lot of money on that truck. Hopefully he won't have to hav a tune for it to run either. Summit racing didn't say anything about needing to tune either. What does switching to MAF do. ( mass air flow) correct. Only reason I know is from my cobalt ss lol
 
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Old Feb 8, 2012 | 08:09 PM
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Oh yea, forgot to answer your question. When he ordered the cam he also got a new timing chain so hopefully that will fix the problem
 
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Old Feb 8, 2012 | 09:59 PM
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If he keeps the stock heads and intake he really shouldn't need a tuner. He will also need new flat tappets with that cam. (if they didn't come with the cam)

Yes MAF is Mass Air flow. It can run a more aggressive cam, than the SD EFI. (A choppy idle cam, like the E303) Also if you open the engine up where it can breathe, the MAF will adjust the fuel based on air flow.

Its a major conversion. You will need conversion wiring harness, Mass Air sensor, Mustang EEC, Tuner, plus the plumbing for air into the intake. All this means $$$$, but also high performance.
 
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Old Feb 9, 2012 | 04:51 PM
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Thanks for all your help man. I appreciate it and I'm sure he will to. I'll tell him to make the MAF his long time goal. Lol.

Thanks,

Trey
 
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