Skip to main content ↑ ↓
Topic: intake question... (Read 1452 times) previous topic - next topic

intake question...

ive been thinking of rebuilding my 84 5.0 in the winter but i need sone questions awnsered before i go ahead and do this. im gonna put flat top pistons in it insted of the dished so i can gain some more hp and more compression. now should i reuse the old wrist pins and connecting rods or just go and get all new rods and wrist pins? i already know i prollt gonna need new berrings and all. and with the flat top pistons would it be better to put the e7 heads on it or  keep the old ones and same with the intake? cuz i remember reading on here somewhere that the cfi is the same as the 4 barrel carbs ford had on these cars. so is it possibul i could go with the rpm performer intake for these engines? plus i already know im gonna need to make the cfi bores bigger if i do this and i do plan on it thanx to jcassity and giving me the info on that:D so any and all replys would be appreciated so i can get a game plan made up before winter hits again. thanx in advance.

Re: intake question...

Reply #1 –
why not go with valve reliefs and mill the e7s as far as building compression goes? seems like a much safer way IMO.
2005 Subaru WRX STi|daily driver

Re: intake question...

Reply #2 –
why not just bore the engine over .30,throw in forged pistons that are dished, throw a new cam in, TF heads, and top it off with that edelbrock intake?

Re: intake question...

Reply #3 –
where to start...

flat top pistons offer no compression difference over the valve reliefs, which also mean no power gains, and compression doesnt always mean power

E7 heads work with the pistons with valve reliefs, use the pistons with valve reliefs

the CFI intake is the same as a 2bbl intake manifold, not a 4bbl, and i dont know if a carbed manifold would have any sensor provisions that a stock CFI manifold has
It's Gumby's fault.

Re: intake question...

Reply #4 –
Quote from: 87thunderbirdBlackJack
why not just bore the engine over .30,throw in forged pistons that are dished, throw a new cam in, TF heads, and top it off with that edelbrock intake?

remember, CFI=speed density
It's Gumby's fault.

Re: intake question...

Reply #5 –
so basically i would have to throw down tons of cash to make this engine have more hp over stock? im not looking for mutch just enough to make me happy. and around 250 hp will do that. cuz i still whant it as a daily driver and also have the power there when i need it. but in the engine now is the dished pistons so it would build a little bit more compression over stock. also i know i would need to improve air flow thats why go e7 heads and a different intake. plus i could drill and tap the carbed intake for all the  sensors needed. but im just seeing if it is possibul to run this set up sicsessfully without any reliability issues. thats why i put it up here first to see what all of you guys had to say bout it. whish jcassity or tc50 would jump on this and help out.

Re: intake question...

Reply #6 –
slap on the E7s. you'll need the 'dished' pistons for clearance issues so keep them. and since the CFI unit is the same as a 2bbl you'll need the adapter to run the 2bbl on a 4bbl intake. not sure if edelbrock comes with one or not, don't remember. hope that helps.
2005 Subaru WRX STi|daily driver

Re: intake question...

Reply #7 –
And someone tell me what is wrong with 1984 heads...?

Nothing. They're perfectly fine...I'm going to move against the grain here and say you should have them freshened up, then reuse them. They flow just fine and are comparable to the E7 heads. The 1984 5.0 was pretty well built from the factory and it's a lot more durable than a lot of people give them credit for. I think you have a better chance reusing it, slapping in a hotter cam, throwing on a 4-bbl carb and new intake, and going like hell. It would be more economical that way, anyhow. Is the engine alright the way it is, or does it need rebuilt?

Re: intake question...

Reply #8 –
i would have said *use the 84 heads* if i knew they were good in compairison to the E7's

port the heads a bit, just have the ports cleaned up on the exhaust side, do a full headers back exhaust, throw some 1.7 roller rockers on it, i dont really see why an edelbrock manifold *wont* work, if you use a carb adapter, but youll probably lose EGR, im not sure, and id hate to see you spend the money, lose EGR, and fail emmissions
It's Gumby's fault.

Re: intake question...

Reply #9 –
well eric the engine has 64000 origional miles on it and its 21 yrs old so all that wear and tear on it probably should be rebuilt in my opinion. but there is really nothing wrong at all with the motor just would like to make more hp outta it. so freshen up the heads and what about the pistons? flat top with valve reliefs? no? yes? what? and also jcassity gave me a great idea by getting the butterflys out of a 4 barrel carb and stick em on the cfi and bore out the runners i belive there called to match the butterflys. would that work if i did some of these motor and exaust mods. cuz im trying to get a game plan cuz its possibul i could be starting this soon cuz the fiancee is looking into getting a loan for a 94 tbird super coupe we just looked at today. so keep all the good info comming my way i need it. thanx again

Re: intake question...

Reply #10 –
you want to rebuild a 64,000 mile engine because of "wear and tear"?!

i know probably 10 people off of my head running 80-100K more miles on their engine, with forced induction, some wild mods, and they beat on the cars...

if youre going to go through the work of boring the CFI...why not go EFI? or why not go carb?
It's Gumby's fault.

Re: intake question...

Reply #11 –
well i whanted to keep cfi to be different but reading on erics site bout tbi to carb conversion its alot easier to do the carbed set up than origionally thought.so its possibul i could be leaning twards doing the carbed swap soon. just wondering what numbers i could be looking at going this route?  and also what other mods i could be looking at by doing this swap becides what was mentioned in the article?

Re: intake question...

Reply #12 –
the thing is, no one builds on the CFI for a reason, sometimes going through all the work, to not make great power, isnt worth being different

going carbed opens up a lot of options, you could run pretty much any cam youd like, within reason, same with heads, intake manifold, the carb doesnt care
It's Gumby's fault.