Will a 347 work with stock H/C/I?

Zero Signal · Dec 7, 2010

So, another chapter in my little on-going saga to get my car reliable again, I believe I may have bad rings in the #1 cylinder on my stock/junkyard motor. I really don't want to spend a bunch of time/money rebuilding the short block, oy vey!

Now, before go crazy with how stupid of an idea that is . . .

I have a perfectly good unused 347 short block all wrapped up since I could never afford all the parts to properly kit it out. I had it built awhile back using my old factory block. It's internally balanced and I have the balancer and flywheel for it already as well as the oil pump. I don't want to buy a bunch of stuff, so I was thinking I might try running it as-is with all else being totally stock. It's designed for 10.5:1 compression on a 52cc head IIRC.

Will this thing run with factory H/C/I on it?? Obviously not optimal, but I just want reliable right now. I have a tweecer I can use if I have to. I'm just hoping it won't be necessary. I have MLS head gaskets I WAS going to use for my fantasy engine, but I supposed I can get my stock heads properly milled for them and give the MLS gaskets a go?

blksn955.o · Dec 7, 2010

it will run...if that is what your asking as long as the pistons have the correct valve reliefs and what not.

Just dont expect much more out of your factory H/C/I.

revhead347 · Dec 7, 2010

It'll run. You just won't be able to run a lot of timing on it because of the iron heads. MM & FF had an article a few years ago where they did a factory rebuild with a 347 short block. It ran fine, and I think it made something like 7 more hp than stock.

Kurt

Zero Signal · Dec 7, 2010

It does have the valve reliefs on the pistons, sized for larger than stock valves. Hey, I suppose if it works, any H/C/I upgrades I do would be that much better

2002BLGT · Dec 7, 2010

Leave it wrapped up till you can put good stuff on top of it , I had a guy bring me a 95 GT recently to tune with 347 stroker kit , Edelbrock RPM 2 intake , E 303 cam and yes stock E7 heads , my wifes stock 95 cobra will run circles around it just simply from having matched components makes that big of a difference

blksn955.o · Dec 7, 2010

Zero Signal said:
It does have the valve reliefs on the pistons, sized for larger than stock valves. Hey, I suppose if it works, any H/C/I upgrades I do would be that much better

The real issue would be if they were for non in-line heads like some CHE/Cleavland style head. Most of the pistons that can run non in-line heads also work with in line heads but there are some that are one or the other.

If you need a car...put it in and upgrade down the road. One fall in college my DD blew up the day before finals and my replacement DD was about a month from being on the road. My 94 was down to the shortblock as I popped a HG (and had a loss of 30% comp on one cyl). I had to put my heads back on a shortblock I knew was weak and study for a final all in 8hrs or so. Did what I had to do in order to have something to drive to finals.

BlackVert · Dec 7, 2010

go for it. it's better to actually get some use out of it then it would be to just have it sit there for who knows how long?

there are times when we all need to make (and take) compromises. you are on a budget, your jy shortblock is bad, and you have a perfectly good shortblock ready to go. it makes perfect sense.

as you admit freely, it would not be optimal, but it is sure to be better than a JY or budget rebuilt 302

how long has it been collecting dust?

Zero Signal · Dec 8, 2010

I had the 347 built in 2005, with the best balance/build/parts I could get for $2500. Nothing crazy, but enough for a hot N/A setup. I've kept it wrapped up, only to unwrap it a couple times each year to cover it in oil and spin it with a wrench. It's still spotless. It's so pretty, I kind of hate to run it, haha.

As far as the pistons go, the build was assuming standard valves angles. At the time, I 'was' going to buy Brodix ST 5.0R heads.

revhead347 · Dec 9, 2010

2002BLGT said:
Leave it wrapped up till you can put good stuff on top of it , I had a guy bring me a 95 GT recently to tune with 347 stroker kit , Edelbrock RPM 2 intake , E 303 cam and yes stock E7 heads , my wifes stock 95 cobra will run circles around it just simply from having matched components makes that big of a difference

Two mistakes here.
1. Your customer put an E cam with stock heads.
2. Your customer put a letter cam in the engine in the first place.

It's got nothing to do with the short block.

I say go for it. Then all you have to do later is put heads and cam on it. Why spend the money on building another bottom end when you have one that's perfectly fine? Furthermore, why spend money on another suspect used engine?

Kurt

nmcgrawj · Dec 19, 2010

revhead347 said:
Two mistakes here.
1. Your customer put an E cam with stock heads.
2. Your customer put a letter cam in the engine in the first place.

It's got nothing to do with the short block.

I say go for it. Then all you have to do later is put heads and cam on it. Why spend the money on building another bottom end when you have one that's perfectly fine? Furthermore, why spend money on another suspect used engine?

Kurt

x2

I wouldnt look for a HP advantage....your torque curve will be better though. I'd look for gains in that area.

lol @ giving advice based off a mismatched combo. The stock components are not mismatched. That crappy combo tuned above is.

That said i would be interested in seeing what would be faster, a 347 with e7/stock cam/stock intake vs a 302 with gt40/cobra intake/cobra cam.

I think its important to remember that this decision is NOT about going fast. Its not about being the fastest thing on the road. So if a 94 cobra will "run circles" around it...so be it. 90% of v6s today will run circles around a 94 cobra. Let alone...how many v8s will simply laugh at it

YEAHLOH95 · Dec 23, 2010

i say go for it put it in and i bet you will be surprised on how good it feels ,it should have a good bit more tq, but i would try and swing a cam, i'll bet you could find a used f somwhere that way all you have to swap out later is the intake and heads

Zero Signal · Dec 23, 2010

I actually have a CompCams XE270HR cam I bought when I did the shortblock. I'm not sure I want to deal with the tuning issues with that. But I agree, I doubt I'd get much HP from it, but there's no way I wouldn't see some pretty good torque gains.

We'll see. I did a leakdown test last night (with a crappy tester) and found nothing unusual with the cylinder I suspected to be bad. I may try modifying the tester with a higher pressure gauge and see what happens. The bores look clean though.

YEAHLOH95 · Dec 23, 2010

well if you already have that cam you may be good wjhat is the canterline on it? the extra cubic inches will make that cam act smaller

Zero Signal · Dec 23, 2010

If memory serves me right and this is the cam, here are the specs 35-351-8 - Xtreme Energy

The grind is etched into the front of the cam, so I can pull off the retainer and look, or call the builder and see if they have a record of it.

YEAHLOH95 · Dec 23, 2010

you should be able to run that no problem just get some springs from your stock heads and go

stangbangerrick · Jan 6, 2011

I go for it and I would use a steeda #19 cam and some heads and intake from a 5.0 ford explorer.

revhead347 · Jan 6, 2011

If it's stock heads, just use a stock cam for now. That Extreme Energy cam is way too much for stock heads. It will run like crap. You'll also be wasting money on upgraded springs for heads you don't want to keep anyway.

Kurt

Will a 347 work with stock H/C/I?

Zero Signal

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blksn955.o

revhead347

Apparently my ex-husband made that mistake.

Zero Signal

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2002BLGT

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BlackVert

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Apparently my ex-husband made that mistake.

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YEAHLOH95

Zero Signal

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YEAHLOH95

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revhead347

Apparently my ex-husband made that mistake.

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