I`d go w/ a 331,because it has a better rod to stroke ratio,and will take more RPMs than a 347.Put studs and a girdle on the mains,then get a custom grind cam for the blower w/ hds. to match.This combo should last a long time if built right.
What type of Roots system are you thinking about. I had one on my Model A V8 Flathead (made 315HP), but you need to be carefull on timing and compression. I used an MSD Boost retard setup which will allow you to take the signal from the carb (if you use a blower carb) and advance and retard the distributor...................one thing about a roots type system is backfires can be the "kiss of death" for the motor as well as detonation. I used a Weiand 141cfm, (I only had 289ci in the flathead) and you may want the Weiand 174cfm. One thing to be aware of is that the Weiand blowers run hotter that a Whipple or some of the others, but as long as you keep the pressure down to under 9psi you should be ok. I used a Demon Blower 650cfm carb which was easy to get the boost signal to the BTM so you can pull timing out at higher RPM's. I would think you would want to keep the CR to around 9.5 or less.
i wouldnt stroke it. the roots blower will make more than enough torque. when stroke a motor with every thing else being the same you are just moving the power band down. it will make the same hp but a little more torque. the 302 rod to stroke ratio will be just fine. when you start stroking the motor the piston starts getting shorter and having compromises built into it. i would use the stock crank and block. get some good rods and pistons, a blower grind roller cam. good aluminum heads and the blower. get a good blower carb. you will want to get the carb from a company that will talk to you on the phone and ask you questions so they can set the carb up correctly for your motor. if you get an off the shelf carb you wont get the best performance and could have all kinds of tuning problems.
I got the idea with stroker kit! I can let it go if you say so. My problem is that I do not know a lot what does good mean... What's more, there isn't even any one to ask in Poland about it. So maybe you guys can help in choosing the parts. Let's focus on heads first, than I will ask for more
i would suggest starting with the blower. im not sure what options there are for roots blowers right now for the sb ford. you want one that is properly sized for the power level you want.
heres a good artical on the one popular off the shelf kit i could find http://www.carcraft.com/techarticles/ccrp_0902_manifold_swapping_for_roots_blower/viewall.html
there are a few errors with that article, the biggest is the mention of a 8-71, I believe they meant a 6-71,which would be fine for a small block. and a supercharger will make up to some extent for the inefficiencies of the heads. there are a number of companies that make roots blowers for the small Ford. personally I'd go with Hampton, but BDS and several others offer full kits and can answer any questions and provide help as needed.
It depends on the cost to improve them and what is needed, (new seats,new valves,new springs,etc. If it is very costly you would be better off to get different brand of heads and just change springs to match cam. With this being said it is just like everything else you ask about on the internet, some will swear by them others wouldnt spend any money on them. Personally I would go with a different brand such as AFR,Trick Flow,Canfield or even Edelbrock
how fast do you want to go? I know you are talking blowers, but you can build a naturally aspirated stroker that will put you in the tens, Im old school, as you could tell with my 8500 rpm revving boss 302 engine, but I think that keeping it simple makes everything easier, you can build a 347 with a 302 block, with an aluminum head you can run 11 to 1 compression with pump gas, a roller cam with a 750 carb and make 500hp wich will put you in the tens, put it together with a ford or dart ( I prefer ford, they are made in usa) block, an eagle crank and rods, and you will have a good bulletproof block. just my 2 cents Duane
Like Yellow75 said, these heads are made in China and some of the finish machine work is done here, but the valves/springs/retainers/seats/keepers are as cheap as they can find. You will spend quite a lot of extra money buying new good quality valves/springs/retainers/keepers to make these heads work with a high HP motor..................I know you don't want to spend a lot of money, but buying cheap quality parts will only lead to broken parts or even worse, a ruined motor..............IMHO
I am aware that hp have to cost. I was looking to get only the castings and than buy the rest, but I will look in to other heads. I bave seen that you can get Edelbrocks for around 1100 and that is in my budget.
Edelbrock makes a good prdt,but that hd. won`t make the power of the canfields,AFRs,Darts,Brodix or some of the others.
