Going From 302 To 347, Which Parts Can I Reuse?

[Airwolf_5.0]

Hey guys, right now I have a stock block 5.0 motor in my 88 Mustang LX with H/C/I and am thinking about going with a 347 short block soon.

My question is: how many of the parts which I currently have (and have spent good money on) can I reuse on the 347 short block without being crazy restrictive on the new engine? Obviously I don't want to leave a ton of HP on the table because of the parts I'm using but I'm ok leaving small bit if it'll save me from buying all new stuff.

Right now I have the complete Edelbrock Performer Package (Edelbrock performer Upper/Lower intake, cam shaft, cylinder heads, 70mm throttle body). I also have 24 lb/hr injectors, 255 lph fuel pump, 76mm Mass air calibrated for the 24 lb injectors.

It would also be nice to have the option to add a supercharger at some point down the road to the 347 setup, but initially it would be NA.

One last note: If I have to swap a few things, I would like to stay with Edelbrock branded stuff... I'm pretty partial to them. Thanks for the help!

EDIT: Just realized I posted this to general talk, should have posted in engine swap section. Can't find a way to move it. Sorry about that guys, this is my first post here....

 

[rbohm]

you can use everything except the rotating assembly.

 

[Airwolf_5.0]

Will I be leaving much horsepower on the table? I am sure 24 lb/hr injectors, and the performer intakes are probably not ideal for a 347....???

 

[tannerc91gt]

Will I be leaving much horsepower on the table? I am sure 24 lb/hr injectors, and the performer intakes are probably not ideal for a 347....???

They're fine. You're not gonna make enough to max out the 24s.
Not a fan of edelbrock parts at all really (their performer series at least)
But you seem partial to them. It'll all swap just fine

 

[RangerJoe]

You can use your current HCI combo, the question is how much HP will you give up. My guess is about 40hp.

Joe

 

[7upstang91]

More than likely going to have to step up to a 30lb injector.

 

[mikestang63]

What cam are you using. You may be leaving hp on the table using a cam for the smalller cubes. I've never been a fan of 24 lbers but if you play with the FP you should be ok with them. My first choice would be 30's.

 

[revhead347]

Since you are just considering going to a 347, let me just throw a wrench in there. I don't think there will be much gain with a stroker kit. If you are reaching peak power on your current setup (which I guarantee you are, probably right around 5400rpms), then more stroke is not going to gain you any power. It will probably move it down to around 5100 rpms, but that's about it. That is to say, that if your engine currently peaks out, and then starts to fall off on the dyno, that peak represents the point where the engine sucks the heads to their max flow.

Now, for further down the road, the 347 is going to hurt you with the blower. The added stroke in a stock block makes it very hard to keep compression down. The lowest you can reasonably go without custom pistons is around 9.8:1, and that's with an inverted dome piston. While you can run a blower with that much compression, it is not optimal. Also, stroker kits are expensive. The cheapest one I would ever buy is $1930. There are kits available online for around $900, but they come with a cheap Chinese finished crankshaft, and cast pistons. If you want to run boost later on, cast pistons is not a good idea. If you want to know how good a $250 Chinese crankshaft is, there are several videos on youtube of these crankshafts on lathes showing cracks and distortions right from the factory. I have read several accounts of these crankshafts breaking almost immediately. Some say a particular brand is better than the others, but other engine builders will tell you that they all circulate amongst different manufacturers in China, and you can never tell.

Let me suggest another method of spending about the same money, maybe a hair more. Instead of dropping all that money on a stroker kit, I would use it to buy a 4 bolt block, like a Dart SHP block or something like that. A better block is always a good investment. Then buy a good set of forged 306 pistons, and a decent quality set of rods. The stock crankshaft is ok so long as you don't spin it to hard. If want to spend a little extra money, buy a forged 3.0" stroke crankshaft. You would have the compression right in the 9:1 or lower range if you want and really be able to take advantage of the blower. You will also not have to constantly worry about cracking the block.

Kurt

 

[Airwolf_5.0]

Thanks guys, I got some really good info. So right now I am leaning towards a professionally built 347 short block (from somewhere like DSS Racing) with forged internals so I know it can handle the power. Then I'd like to slap my performer package on it. I'm just afraid the performer stuff wont flow enough for the added cubes and will be seriously restrictive. Not sure though. Maybe if I could scrape together the money it would be worth going to Edelbrock Performer RPM intake/heads? Maybe even the Edelbrock Victor stuff? I heard those flow a lot better for bigger motors. Any input?

Since someone asked the cam I have is just the "Edelbrock Performer 5.0 cam" made to go with the package... not sure on lift and all that at the moment.

 

[GroverDill]

Unless you need a new motor now just add the blower and run what you have.

No matter the internals or build a stock block will normally crack before anything internal.

You do understand that a 347 is still a stock block , unless you pony up for a 4 bolt aftermarket block.

 

[mikestang63]

Thanks guys, I got some really good info. So right now I am leaning towards a professionally built 347 short block (from somewhere like DSS Racing) with forged internals so I know it can handle the power. Then I'd like to slap my performer package on it. I'm just afraid the performer stuff wont flow enough for the added cubes and will be seriously restrictive. Not sure though. Maybe if I could scrape together the money it would be worth going to Edelbrock Performer RPM intake/heads? Maybe even the Edelbrock Victor stuff? I heard those flow a lot better for bigger motors. Any input?

Since someone asked the cam I have is just the "Edelbrock Performer 5.0 cam" made to go with the package... not sure on lift and all that at the moment.

Unless you are racing the car, then don't worry about getting every single HP from the build. You can easily end up spending 8-10 grand on a motor. Forged internals in a stock block are a waste of money. Plently of guys run 400hp and up on stock block motors.

Now don't take my word alone, but DSS would not be my first,second, or tenth choice for a motor. If you can't build it yourself, first find a local builder that you can visit and establish a relationship with. If you want to farm it out to someone, then I would either call in this order Woody at Fordstrokers ( be prepared to wait about 6 months) or Mark Oneal at CHP. Both will build you a quality motor.

 

[stykthyn]

Chp is great. I have dealt with them several times.

 

[revhead347]

DSS uses cheap parts and their engines are assembled by students at UTI trying to get experience. I'd pass.

Kurt

 

[reldla1996]

When I went from a 306 to a 369 a couple years ago, the only part I transferred was the Holley Systemax intake. I up sized every other part, from MA to headers.

 

[RangerJoe]

DSS uses cheap parts and their engines are assembled by students at UTI trying to get experience. I'd pass.

Kurt

I've never heard that about the UTI students before. Not arguing over it, but how did you find that out?

Joe

 

[MikeH686]

Getting a DSS assembly you'll find that the way they balance their kits is taking different pistons from different companies. My buddy had one that started having oil pressure problems took it apart and found he had four name brand pistons in his assembly (je, Keith black, probe, and I think cp) either way they take whatever pistons are closest in weight and cc's and slap them in. I would steer clear of them

 

[revhead347]

I've never heard that about the UTI students before. Not arguing over it, but how did you find that out?

Joe

I had a friend who bought a 306 from them a few years back against my advice. It tore itself apart within 3000 miles. When they pulled it apart they found it was completely filthy inside. Whoever had assembled the engine had never bothered to keep anything clean which is critical in engine assembly. The dust and machine shavings had just shredded the crank and rod bearings. He sewed DSS and won. That $5000 306 ended up costing DSS $14,000 after legal fees. Anyway, he flew up to Chicago to negotiate with DSS, and saw their shop. Everyone on the work floor wears their technical school clothes there after class to work on engines. He ended buying an engine from Woody at Fordstrokers which is not far from DSS, and there are guys there who used to work for DSS and told him all the horror stories.

I have never heard about DSS balancing their engines with different brand pistons. They are actually casting a lot of their own stuff now. I'm sure they do not have the piston casting experience, and are doing so only to drive down costs further. You get what you pay for when it comes to engines.

Kurt

 

[RangerJoe]

That's good information to know Kurt!

Joe