Right now I have mm exhaust, IM heads,roller rockers,mikuni, and high rev coils. After hunting season I'm having a new cam installed. I'm looking for low end torque and load carrying capabilities.I need opinions on what cam to go with. Also while the engines cracked open should go with the BPS pistons and rods or just stay stock? I plan on leaving the 4700 rev limiter on to try and stay as reliable as I can. Its a 2010 cdi prodrive.

Im happy with my cam from Hoyt at Gator-Tail so I can only comment on it. Low- mid range power is Outstandding compared to stock. If your cruising and you let off the throttle to turn and you have a heavy load, and you get righ back into it you can hear the motor rapping back up without lugging.

I have a new bps cam and like it alot it pulls hard threw all the rpms and it jps out the water quick and I can carry a big load with it and still pulls good

I have a Bps cam, dad has a 493. We're pleased with both. Really changes the way the motor runs as Marcus mentioned above.

If you have the money for the pistons and rods, go for it!

[quote="cb5331"]I have a Bps cam, dad has a 493. We're pleased with both.

Which one seems to have better low end torque?

Honestly they both seem to have a great hole shot. I have not driven my dads very much though. Mine has awesome power no matter where the throttle is. If I hit it, it goes whether off idle or already cruising half throttle. Neither seem to have any lag even with stock carbs.

Are most of yall still running stock pistons and rods with the mods i have? I guess my question is will the bps piston and rod make my engine stronger and will I lose or gain any reliability.

i wouldnt do the pistons and rods with the iron mountain heads.... will be to much compression

The bps parts are designed to work with each other. The 5500 and 7000 both have pistons and heads. Compression is not too high. They still run on pump gas

he will stay on the rev limiter and crack the block on a prodrive..

my buddy had stock internals with his heads cut 65 thousanths with a hoyt cam... cracked the block after 60 hours.

The block didn't crack because the heads were decked...

You said you had a 4700 limit, so I'm assuming you have already upgraded the coils? If that was wrong, then you would need the 4700 rpm coils to get the most out of those mods. I would not hesitate to build that motor all the way up to a 5500. If you follow the steps Gary and Andy have posted on putting the case back together, it will help with case leaks and cracking blocks. If the case can't shift or torque, it's much less likely to crack.

Yeah i have 4700 coils. I can turn a new prop 4550rpms now. Would just adding the cam put me back on the rev limiter?

My heads are IM but I got them to make em 50 thou

You should have said that earlier... I would be hesitant to add pistons if your heads are decked that much. You said IM heads which are only decked 30 thou and are designed to work with the BPS pistons and rods. You don't really have IM heads, you just had BPS do your headwork.

Yes a cam will likely put you back on the limiter. You may try a slightly more aggressive prop also.

Where are you located? Who is doing your work?

Are the heads, cam, exhaust, rods, pistons, carb, rockers really that good to last for someone who actually uses It foreverything and not just for duck season. If there supposedly that good why are there so many engines that didn't make it past 100 hrs.

Which ones didn't make it past 100 hours?

I've talked to quit a few ppl around town that have done modded out motors a few times and theyve blown every one of them

BPS motors?

They just said what they did never said who didn't it and I never thought to ask

I hate to toot the midget's horn, but the BPS recipe seems to be pretty reliable. I've seen plenty of those 5500 and 7000's with hundreds of hours on them.

Other companies, yeah there were a lot of em that did not make 100. I'm sure there has been a few of the BPS engines go up as well, but they also have a lot more engines out there.

Well guess I'll be throwing some change out there and see how reliable they are then. See if my kite of a boat will run 40

Well guess I'll be throwing some change out there and see how reliable they are then. See if my kite of a boat will run 40

To me the reason motors come apart from time to time is nothing can be overlooked, under tightened, over tightened, not oiled or greased before it is installed, etc. etc. etc. these motors have to be built with good knowledge of what you r doing. Or else the end result will be failure. So if you do intend to build a motor find yourself a reputable builder that really knows the ends and outs and pays careful attention to parts being installed and their tolerances. If your a first time builder it can be done, but I will say take your time and don't get in a hurry.

Buy good parts don't settle for junk.

100+ hrs on my modded motor not a single issue. I fish year round from my rig.

I heard at sea level with the extra compression of adding the pistons and rods will start to cause det with just 91 premium with no ethonal?.

This is with the iron mountain heads,cam,exhaust,carb

Bayouboy has done all the wrenching on my motor. I have about 80hrs on mods I have currently. If I just add the cam should my comp. stay nunder 200lbs? The way it sounds I shouldn't do the the pistons and rods. As it is my motor runs very strong but you know how it is your always looking for more.

Why don't you ask Preston? He's worked on plenty of these motors and I would be inclined to entertain his opinion on it.

FTR, BoatDr runs a 7000 at sea level and does not seem to have any issues. I know he has sold and built plenty of 5500's and 7000's to those in his area as well.

The cam will not change the compression enough to worry about. Only way to really change it drastically is pistons/rods, or headwork.

Dynamic Compression ratio.... Hmmmmm Never thought about it that way. its the actual REAL amount of air thats being compressed.

You sir are correct

Thanks Cody. Keep it coming.

Did you learn what you know from schooling or just a desire to tinker and lots of research on your own?

Just saying. LOL. A lot of the best guys in numerous hands on type fields have no formal schooling. Just curious what his background was.