supercharger

[64 200 ranchero]

will a m90 work with a 170 engine??? if not what is the best way to boost it
and is the blow through setup for a m90 safe and which is better blow through or standard :

 

[Asa]

i combined your two threads into one

now, to answer your questions
an M90 should work, i'm not entirely sure if it would be the best supercharger to mate to a 170
if you wanted to make power out of an I6, i'd look at getting a 200ci I6, the 170 has five main bearings, and is a smaller displacement

you can use a M90 for a blow-through, or a draw through (where the fuel is pulled through the supercharger), if you do this you have to upgrade the seals in the supercharger so that the grease lubricating the bearings is not washed out

 

[Falcon Ranch]

if you wanted to make power out of an I6, i'd look at getting a 200ci I6, the 170 has five main bearings, and is a smaller displacement

I will agree about the upgrade to a 200ci VS the smaller 170, but have to disagree about the 5 bearing block being weaker...almost every V8 on the market has 5 bearings and 2 more cylinders, does this make them less attractive...I also have read that those GM stovebolt 6's with 5 bearings are pumping out 500+ HP...I personally have a '62 200 with 5 bearings and am pushing 225 HP. I am a firm believer that the lesser bearing engine being weaker is not true...until I drop a crank or see someone who has dropped or broken a crank because of having only 5 bearings, I will believe otherwise...Yes it is nice to have more support and 2 more bearings make a big difference and at the same time offer more oil surface.

I guess it's just a personal preference.

dave 8)

 

[StrangeRanger]

On a V-8, the bearings are close coupled because the rods from the opposing banks share the same journal; there are no unsupported journals. This construction is similar in strength to a 7 bearing I-6.

On a 4 or 5 bearing I-6 there are consecutive journals without a supporting bearing in between; it is an inherently weaker design. Whether it is sufficiently weaker to make a difference in a street engine may be open to debate, but if it makes no difference, why did Ford feel it was necessary to spend the substantial amount of money required to re-engineer the 200 as a 7 bearing engine?

 

[Falcon Ranch]

Maybe it was to reduce the mass in the crank that the early engines had...I understand what you are saying StrangeRanger...I am sure this subject could go on for eternity...I am personally testing my '62 to see what kind of HP it can handle...I just see so many throwing out a perfectly good older engine for one with the 7 bearings...I am one of them, as my '61 Ranch already had a rebuilt 200 from a '62 Fairlane and I know what I wanted to do to it, so I figured I would test it to see what it is capable of...if I can prove that the early crank is capable of certain HP abuse, then maybe this saying of early blocks are weak will subside a bit...until someone proves it, people will be afraid to use it...as of now I am pushing 225 HP which is a lot more then 95% of all N/A sixes on the road today.

My quest is to see if I can run 1/4 mile passes with a turbo pushing 350-400 HP repeatedly...if I can do this, then maybe people will think different about the early blocks...this should prove their strength, right?

Dave 8)

 

[rbohm]

8) it isnt that the crank is stronger or not, both are actually similar in strength, but as SR indicated there is much better support for the crank with 7 main bearings than with 4 main bearings. where this comes in to play is in preventing certain harmonic vibrations at the crank when trying to get a lot more power from the engine than it was originally designed to produce. the lack of bearing support creates a flex point in the crank, and as power levels and rpm levels go up, it becomes a stress riser on a large scale.

as to the M90 supercharger, yes you can use it to power up your 170, the biggest problem is in mounting the supercharger, and the attendant drive system. solve those problems, and post pictures. i would use it as a blow through system by the way since the charger is designed to work on EFI cars, so as evan indicated the seals wont handle dealing with fuel. one more thing, use a blow off valve to relieve stress on the piping between the supercharger and the carb.

 

[Falcon Ranch]

I wont argue the fact that you get more support with the 7 bearing block, I totally agree...I am however going to see how much power it will handle...the early cranks are inherently very well balanced...as I do not have a harmonic balancer...if I can repetitively beat 250-300 HP thru this early block with no problems, then maybe people will stop trowing a good block away...I always see in many threads where someone is recommending the other guy to throw out that ealy block and up grade to the stroger 7 bearing if they plan to do any mods...95% of most engines out there that are in Mustangs and Falcons are N/A engines with no more on average then 125-150 HP...so if they will keep the early block then they will be ahead and know for a fact how much power it will take.

 

[tjnavyblue]

225 HP is great NA - probably the highest hp street 200 I've seen on here. Are you using the aluminum head? Were you able to dyno before you installed it in your ranchero, or after?

I greatly considered dynoing (my machine shop offered me two full days of dyno runs for $500) but didn't have the cash at the time. Now I'll tune the best I can, and take it too a chassis dyno sometime in the future.