1985 5.0 Cylinder ?

[32ratrod]

I measured the cylinders in my 302 and they are 4.005" is that enough to worry about boring and honing or is there a more economical way to go about closing up the gap. I am a college student and I dont want to spend the money if I dont have to. Thank You.

 

[93 LX]

well if you bore it then you will need over sized pistons. honing normally just removes a miniumal amount of material so sometimes you are fine with a new set of springs... go get a 87 trough 92 engine.. better heads and you have eye browed pistions so you can run a bigger cam without valve to piston clearence issues.. jusy my opinion

 

[stykthyn]

ditto on the 87-93 engine or better yet would be an explorer motor. If you shop around they can all be found for a pretty decent price and the explorer will give you at least 80hp over stock.

 

[32ratrod]

I have the roller motor and I am putting the GT-40 iron heads on it. The pistons that are in it already do have the eyebrow reliefs in it. So since the cylinders measure 4.005" I should be good if I buy a new set of rings?

 

[85_SS_302_Coupe]

well if you bore it then you will need over sized pistons. honing normally just removes a miniumal amount of material so sometimes you are fine with a new set of springs... go get a 87 trough 92 engine.. better heads and you have eye browed pistions so you can run a bigger cam without valve to piston clearence issues.. jusy my opinion

ditto on the 87-93 engine or better yet would be an explorer motor. If you shop around they can all be found for a pretty decent price and the explorer will give you at least 80hp over stock.

Just FYI but all of the 302s from at least '82 to '85 had forged pistons with valve reliefs...they were the exact same pistons as the forged pieces in the later '87+ pistons before they switched to hyper pistons. I believe the lack of reliefs in the '86 was to aid in combustion due to the crappy heads. E7s are a tad better than E5s though and you'll gain roughly :05 compression with switching to them from E5s.

 

[88mouse]

I have the roller motor and I am putting the GT-40 iron heads on it. The pistons that are in it already do have the eyebrow reliefs in it. So since the cylinders measure 4.005" I should be good if I buy a new set of rings?

Mic your pistons and see what they are at. When you take a block to be bored you have to take the piston so they know what size they need to bored each cyl. Same thing with what you're doing. But five thousands of and inch you should be ok. If you get a set of file fit ring you will be in good shape.

 

[Fast63]

yeah, the 85 5.0 roller engine is the same thing so keep it. How much ridge is there in there bore? It should still read 4.000 at the very top of the bore because the rings do not go up that high and there is minute to no wear there from the piston. If there is no ridge in the bore, maybe you measured wrong? When I took my 85 5.0 roller engine apart the first time with 150k miles on it, it still looked like brand new. There was no ridge and basically no wear, so maybe it's fine.

 

[32ratrod]

There is no ridge really... a little diff in the way the light reflects off of it... but my fingernail barely catches on it... it reads 4.000". So .005" isnt enough to worry about? Just get a new set of rings and pop them back in?

 

[PUNISHER RACING]

SQUIDBILLIES FTMFW!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[Fast63]

There is no ridge really... a little diff in the way the light reflects off of it... but my fingernail barely catches on it... it reads 4.000". So .005" isnt enough to worry about? Just get a new set of rings and pop them back in?

well, you have to remember that the bore tapers out when going down. In other words, the bore is supposed to be larger closer to the crank, and the measurement is taken where the deck surface is. Your .005 difference is probably mostly in the fact that it is tapered. Give it a good hone and slap in some new rings I say.