Spooln

Looking for ideas on upgrades where do I start. Dont want to go crazy but on this motor what would I start with heads, cam, etc. Dont want to get into bottom end until it pops. Its on a Crownline 248ccr 7.4 bravo I carb. Already have thur hull exhaust. Looking for the best bang for a buck
Thanks

CAPTAIN JACK

First off what kind of exhaust do you have, stock manifolds with short risers, if you do I would ask myself before you get to deep into it, do I want to spend $1500 to $2000 in aftermarket exhaust, the reason I say that is, as you read on all theses forums about reversion, IMO the exhaust is your limiting factor, if you don't want to spend the money for good exhaust then your limited to how big of a cam you can run. If you do have aftermarket good exhaust, I say let the planning begin, the next is your budget, how much $$$ do you want to spend. I wish I was like you and would have asked questions before I started, because 4 motor projects later and $12,500 later I still don't have one together. I say to myself all the time WTF Just my 2 cents

t500hps

is it a 454 LX or a 454 Mag? If you have the 454 LX then don't bother spending $$$ on it. An engine is a combination of parts working together and you'll need to replace nearly everything to get decent power out of that motor. If it's a MAG then you have a bottom end to work with but like stated you will be buying numerous parts. Would be easiest/cheapest to find a 502 MAG of even a 500 HP and sell your 454 for whatever you can get.

cp5899

iTrader: (1)

If you have cast internals you won't be able to get to far unless your goals are low. I build a set of 781 heads, mild cam high rise intake and a Holley 850. I did all the work myself (I have a machine shop for all the head work) so I didn't have a ton invested but I gained about 4-5 mph. If I would have had to pay for labor and machine work and parts (I had the parts laying around) I would have been in 2-3 thousand which would not have been worth the 5 mph. But..... Since it didn't really cost me much and I didn't have to pay machine shops and others for labor I was happy with the gains.

The base 7.4 cast bottom end is the limiting factor and can't take much in power and in rpms. 5000 is the ceiling so I'm told.

Spooln

Thanks for info
How can I tell what motor it is I believe its a LX with thunderbold whatever that means. And how would I know if I have cast or forged internals? Motor is in 1998 boat Crownline.

Knot 4 Me

Post a pic of the motor or give us the serial number and we can tell you exactly what you have.

dereknkathy

it is also a 24 crownline bowrider. not a fast hull. it will take LOTS of power to make it noticably faster...

1BIGJIM

iTrader: (1)

Unless you have deep pockets and lots of money to spend be happy with what you have and enjoy the boat.

I started just like you 30+ years ago. What can I do to make this 305 V8 faster Then a 350, then 383, then endless big blocks. Listen to the older experienced people on the board, it's priceless.

Regardless of what you decide, any performance build starts with exhaust peroid.. You can make endless changes but if you do not have a good exhaust it will always hold you back. Do a search on exhaust, you will be able to read all weekend.

Good luck

pqjack

i would go with the 502 mag...cheap to buy/maintain,easy to find,good resale value....if your motor says 7.4l on the cover,it's a low-perf version

Pismo10

Find a 502 mag take out or an hp500 take out and sell your motor as a complete unit.