Rebuilding '88 351

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BroncTrouble

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OK...I am starting my parts list for the rebuild I will be doing in early fall. First I am not going to the extreme here, I am keeping the fuel injection and stock computer EECIV but I would like it to be make it a bit more "wild" that the stock 200hp rating.

The rebuild kit I am looking into so far is a Federal Mogul kit w/ Hypereuectic flat top pistons which I feel should be sufficient since I shouldnt be over 5500-5800 RPM range with this rig. With 63cc heads it advertises 9.17:1 comp ratio (should be ok?) ...but the kit doesnt come with the cam, lifters or timing chain.

So, the lifters and timing chain arent a big deal to me...but, I am lost in a sea of cam grind codes, durations and lift. I wish to go as big as possible with out having problems with the computer control equipment or valve clearances...I am also not shy about having to change my rockers or putting on headers if the computer can handle all of this as well.

Thanks!

BT

 

gatorbronco

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If you're just going to buy a cam and not replace your intake, heads, and headers, it probably won't make as big of an impact as changing those will. Remember that a larger cam will try to pull more air/fuel into the cylinders. You should definitely upgrade your intake, heads and headers, and can probably find a TON of info about different combinations, depending on what you are looking for. Don't pay attention to the specific cam numbers unless you fully understand the effect they will have. As for your computer, can't help you much...mine is sitting on a shelf in my garage...

 
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BroncTrouble

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If you're just going to buy a cam and not replace your intake, heads, and headers, it probably won't make as big of an impact as changing those will. Remember that a larger cam will try to pull more air/fuel into the cylinders. You should definitely upgrade your intake, heads and headers, and can probably find a TON of info about different combinations, depending on what you are looking for. Don't pay attention to the specific cam numbers unless you fully understand the effect they will have. As for your computer, can't help you much...mine is sitting on a shelf in my garage...

That is the whole deal, I want to run with the computer. How extreme can I go with it...

 
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BroncTrouble

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OK...so has anyone else put a different cam in a 87-91 bronco? What was it? How did the computer like it?

 

swampthing

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try to contact 89bronco58 he had a bronco EFI 306 with a cam that is equivelant (maybe bigger maybe smaller) to the ford racings B303 cam. im pretty sure he is running with stock computer and everything but he had to buy some sort of spacer or such from ford dealer

 

Justshootme84

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Yeah, you should be able to use the stock ECM with a mild cam swap, either an RV or pulling cam. Just don't get too radical on the lift/duration or venture too far from stock. I think Comp Cams has one or two specifically for your needs, might check their site for more info, JSM84

 
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BroncTrouble

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Thanks, right now I am looking at the Comp Cams #35-255-5 that advertises RPM range of 1000-5200 and Duration 254/258, Lift .478/.485,

or

ntake Duration at 050 inch Lift: 210

Exhaust Duration at 050 inch Lift: 214

Duration at 050 inch Lift: 210 int./214 exh.

Advertised Intake Duration: 254

Advertised Exhaust Duration: 258

Advertised Duration: 254 int./258 exh.

Intake Valve Lift with Factory Rocker Arm Ratio: 0.478 in.

Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.485 in.

Valve Lift with Factory Rocker Arm Ratio: 0.478 int./0.485 exh. lift

Lobe Separation (degrees): 114

is this even worth my money/time? That is the real question I would assume now...is the gain I get worth the money over a stock cam?

Please remember I would like to go as big as possible while runnning that old computer on board

 

Justshootme84

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Yes, that's in the range of 214/215 duration. Just check with the mfg on the pushrod length, and the recommended rocker length.

 

swampthing

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Duration 284/ 284, Lift .480/ .480....that is the specs on the ford B303 cam which is probably one of the bigest you can go without needing computer upgrades etc. IMO its not worth it if you plan to just do cam and thats it...theres odds and ends you can do like upper lower intake, throttle body, exhaust...if money is no object then yes get into cam heads and all that cause thats where you're really gonna see a major gain..but thats just my .02

 

Justshootme84

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Yeah, I was refering to the intake duration. 0.284 advertised duration is prolly the limit on running your stock ECM without any upgrades. I also agree that improved airflow thru the intake and exhaust is vital to making the performance gains worth the money. I repaet the deal on the pushrod length and rocker ratio. Be 100% sure what you are using will work.

 
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BroncTrouble

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Thank you, I really appreciate your time and comments. I will do some digging into other mods and pushrod/rockers.

Thanks again

BT

 

BLADE262US

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I have done this Comp Cams makes one specific for the speed density EFI system you cannot use the B303 or others like that as they were meant for the mass air 5.0 which adjust for changes like this the speed density system is dumb it only knows what it was originally told and doesnt adapt to changes search my post and youll find the explanation of the speed desity EFI and if I remember right the pics and progress of my build it runs very well and I have been really happy with it , I also removed all the emissions stuff the " correct way " so the computer is happy . This place is a very good place to get components I found them on ebay and you just cant beat thier prices especially if you call them and ask for a package deal . Also theres a guy on ebay selling complete assembled aluminum heads for the 302/351 for under $800 a pair you can barely get a set of stockers completely reconditioned with all new components and machine work for that . Heres the link to the engine parts . :D /emoticons/[email protected] 2x" width="20" height="20" />

http://www.fastengineparts.com/

 

swampthing

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i wasnt advising him to use the B303 i just used that cam in reference to the size lift duration etc. sorry if it came off that way

 

BLADE262US

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Thats ok I was just clarifying it . The cam I used if anyone is interested is a comp cams 35-255-5 that is the part number and works very well with the EEC . :D /emoticons/[email protected] 2x" width="20" height="20" />

 

bidibronco

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I have the 94 Bronco and I have the EECIV Speed Density and here are my mods in not particular order; Edlebrock Performer EFI intake, BBK twin 56mm Throttle body, 24# injectors, BBK 35-75 PSI fuel regulator, Flow headers, double valve springs, shaven stock heads, hypereutectic dished pistons, my cam is *Int/EXH* 204/214 duration 448/472 lift with stock rockers but I have 1.7 rockers wich make it something like 468/500 lift. I have done nothing to the computer however, the person before me upgraded the fuel pump and fuel lines. I have a bit of a "rough" idle but anything off of idle is fine and it's got plenty of torque for what I like to do. I don't know if this helped any but I give you what I got....

 

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