help with 7.4L 454

[vimax]

More questions

Could anyone tell me if redoing cylinders at 30 over (whatever that means???) in 7.4L 454 V8 ? 330HP (1994) will increase horsepower and by how much? We have a Bravo drive and I am concerned if the drive can handle increased HP.
Also, I need to get a set of exhaust manifolds for it, however I can?t locate engine number (numbers on flame arrestor are missing, and the one by the starter is S 135039). That number does not match anything?Are the manifolds standard fit for that engine and year?
Thanks for your help.
Vimax

 

[Coors]

Re: help with 7.4L 454

.30 over may increase compression .25? 20 hp
watch for ping; maybe retard timing 1 degree

 

[Reel Poor]

Re: help with 7.4L 454

Boring the engine 30 over will not change the output horsepower enough for any concern, you Bravo drive will handle much more power than your stock rebuild can produce. And set your engine tune-up specs to factory settings.

 

[180shabah]

Re: help with 7.4L 454

Yes your exhaust manifolds are standard. you can Shop around online for big block maifolds and find some decent prices

 

[SuperNova]

Re: help with 7.4L 454

Boring .030 will give you approximately 8,000 more horsepower--you may need to re-prop.
--
Stan

P.S. Not really, it's just a poor joke.

 

[vimax]

Re: help with 7.4L 454

Thaks for your help.
And here I go with another question re; exhaust manifolds. There is quite a selection of manifolds on the net and quite a price range $139.00 - $420.00 each...The question that I have is this: should I get just cheap set of manifolds or spend lots more money and get Ceramic/EDP coated???
The boat is used in salt water.
Vimax

 

[Coors]

Re: help with 7.4L 454

Salt=ceramic

 

[vimax]

Re: help with 7.4L 454

Well, thanks for all your help.
Here comes another question, after the engine has been rebuilt, what is the best way to brake it in? Would running it on land on ?water muffs? help?
And another question?I am going to Belmar area (NY) to do some fishing with my dad, and I am bringing my boat (20 foot Bayliner with I/O engine), the boat has never seen salt water.
What are the risks and are there any precautions I should take before I put her in to salt water???

 

[riverjet502]

Re: help with 7.4L 454

It sounds like you are going to freshen up the O'l Rat motor. In my opion with past experience speaking the best way to break a new motor in is on a dyno. So much easier to do your tuning on and monitor the engine's vitals as it takes its first new breath. Plus you will have a print out of hp & torque curves at every 500 rpms with oil temps, coolant temps, and fuel/ratio all that good stuff you should know. Plus you can easily change your oil filter after a couple pulls on the dyno and cut your filter to see whats happening in your oil. If you are having a shop rebuild your motor (Quality shops should have a dyno and be willing to run your motor to back up their quality work they did on your motor) If not look for another shop. If you do your own work, rent dyno time from a shop. Around here it runs $350 for a day on the dyno including tuning. Good Luck and keep us posted....