Just finished off the race season ( I finally made it to the quarter finals ) but the ol mav isn't fast enough. She ran 12.46 @ 107.63 with the 302. I want more power and torque to make her faster. Streetability isn't a concern for me just the strip. What combo is better and why? I know members on this forum have both combo's and would like your input before plunking down my money.
You know you are opening a can of worms with this question dont you My vote is for the 347, same money to build, more torque and horsepower. Be prepared to spend a few $$$$$ to do it right though as you will need a good cam and heads to take best advantage of either engine. Go to this site and register and read it will give you the answers you seek and really educate you, if you think you are smart now be prepared to feel stupid. http://www.sbftech.com/ I am in the process of having a longblock built by Fordstrokers.com the owner of this site
Also just to note, you can achieve your goals with your motor punched to a 306 and it would be lots cheaper
What class are you running in? How fast do you want to go? I run Sportsman with a 12.00 limit. I asked my engine builder to build me a 347 that would run 12.0s at Firebird in Phoenix. He told me he couldn't do it. I said " Mike, you build high dollar racing engines!!!Are you telling me you couldn't make one go that fast." He said "no, I just can't make a 347 go that slow."
the engine is actualy already a 306 , and has dart heads and lunati cam etc. etc. etc. it just doesn't do it for me any more so I need to tweek it again
I've got a 308 in mine. It's gone 11.81 with 40 pounds of weight in the trunk and taking 4 degrees of timing out.
You want to go fast buy this engine http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=220490176555&ssPageName=STRK:MEWAX:IT That is a really good price believe it or not
hey what color is your mav? i saw a black one on a trailer this morning. it had big racing slicks on the back
I am in the same boat i am tired of my 308. last time i ran a 8.20 (1/8 mile) but have went back after i put my new trans in. i read the 331 works better for a lighter car and the 347 has a bad rod ratio. I also thought about a 351w, 393,or 408? but then you cant reuse alot of the parts.
MAYBE the folowing will help clear some things up. The Following is Cut and pasted from one of the GREAT learning threads over on sbftech.com This a direct quote from Jay Allen (He KNOWS his stuff and can back up EVERY statement he makes with Facts): "Sure a 347 has more side load, no question about it. But it is insignificant. Plus, the smaller engine with a taller R:S ratio will turn more RPM to do ANY job that the lower numerically R:S engine will do. On the corral one of the village idiots over there (5spdGT) wanted to argue this point everytime it came up. He wanted to argue that the 331 would last FAR longer due to the less side load. Okay, go with that. If your 347 is turning 6500 RPM to get a certain job done, the 331 will have to turn 6814 RPM (or 4.83%) to get the same job accomplished. RPM will kill parts at a greater rate than side load. Even cruising down the road in 5th gear, the 331 needs more RPM to do what the 347 is doing at a lower RPM. The 454 BBC has been brought up. 4.00" stroke with a 6.135" rod. 1.534 R:S. A 400 SBC from the factory is a 3.76" stroke on a 5.565" rod. That is 1.484 R:S ratio. Both are great examples of engines that were built when pistons were junk and both engines would last well over 100K miles. Today, the 4 cyl Hondas and Toyotas are taking medium stroke engines with relatively short rods and making them work. 3.50" strokes with 5.45" rods (1.557 R:S) and they turn 8000 RPM and up. How is this possible? Large heads (no velocity I guess) and well designed pistons that utilize off set pins. This lessens the side load and makes for a long lasting piece."
on most 347 stroker kits the piston is so short that the wrist pin interfers with the oil rings and causes it to use oil and more side load on the piston
Where did you get that info?(Its really outdated and is a myth) No one I know with a 347 has any oil usage problems. If you`ll read my above post you will understand that there are several "factory " engines produced that "side loaded " the cylinder walls as much or more than a 347 ford stroker. YET these factory engines didnt wear out quick due to side loading. You say "most stroker kits" which ones are you refering to? There are two different rod lengths used in 347 kits and neither one causes the problem you mentioned. Do you have first hand experiance with this, or did you read it or hear it somewhere?
no, i read in a mustng magazine. i will have to check the date on it could be expired. LOL prob. early 90's so your right prob. fixed that problem. I guess i should throw them away like the wife wants me to
The 347 got a bad reputation from its earlier years and is still trying to live it down, a lot of the problems that they had was from the builders not building them correctly in the first place, or they are not correctly broke in. Even to this day you can pick a forum and read, people will say they use oil and load the cylinder walls, but if you do your research from those that know the truth you will find out that it is all just myths. It is like a big rumor that just keeps spreading and there is no convincing people that it is not true
