454 first build. Suggestions
 

Hi. I'm looking to build a gen 5 454. Carb. Looking to get the most hp I can on pump gas. I have .088 heads,air gap dual plain intake,quick fuel m-850 DP carb. It's going to be bored .30 over. Probably port and polish the heads. Need Pistons,cam and lifters still. Will be running MSD dist and box. I will be getting exhaust also that will work best. Would like silent choice compatible anything you guys suggest or add would be great.

Stainless marine exaust manifolds work well are light and Corsa quick&quiet will bolt up!If that's what your asking:readinghelp:

Unless your doing the head work yourself it's not going to cost much more to get a significantly better set of heads. Sell your 088's and upgrade if your truly looking for the most you can on pump gas.

Are you adding MSD. If so don't.

THat little box in the upper right corner that says "search" use it, there are 45,321,912 threads on 454 builds. decent heads and cam/valvetrain your a little over 500 hp which is nice , dependable and should be drive friendly.

The two in bold above won't work together.

Decide which ypo'll ditch and then we all can go from there.

Im staying out of these 454 builds from now on. For some reason, they bring all the heat.

It sucks that the guys that actually build motors get bashed on here. I like the budget builds. As a first time powerboater their info is essential to my DIY builds. It seems on a 454 the current trend is peanut port heads, a rectangle port mismatched intake. Joking aside I also would like to see a stout na 454 build.

Actually Joe he is going .030 over so he's not 454 anymore. Have at it. ;)

It's a great topic that has been addressed a lot but seems to bring in a lot of opinions, and some people only see one recipe for some reason. There are a lot of ways to do it and guys willing to share. Maybe PM a few of them and what they think. I called 4 different builders and talked to them for a while. Then made the best decision for me.
Good luck with your build.

Whip it is true hit the search button and you will find many builds such as yours, but the people that have already posted know a lot about engines and how to build a solid engine. I would read more and even pm some of the members lots of knowledge on OSO.

Good luck

Well, in that case! lol

Seriously though. Silent choice exhaust is going to limit the camshaft you are going to be able to go with. My personal opinion, is forget silent choice y flappers. We have plenty of sound solutions that can reduce noise, without the reversion issues of silent choice flappers.

The GM heads are going to limit your potential. I'm not even going to touch base on cylinder head talk, as I do not want to wake the bears. :party-smiley-004:

Get in touch with bob madera (rmbuilder on the site) and develope a game plan.
Discuss your goals, budget and the parts you currently have.

After you have the recipe, develope a relationship with an engine builder / machinist local to you.

I'd try to use an aftermarket aluminum head if Your budget allows.
I'd have a custom cam specified by Bob and buy the valvetrain components from him too.
I wouldn't use anything MSD. Use a magnetic breakerless distributor in good mechanical condition and a Daytona sensors CD box and coil.
I'd scrap the silent choice.

I think the key to success in engine building is in the planing
by this i mean finalize your real objectives timeframe/hp/tq/rpm/duty cycle and of course budget. And stick with the plan.
In regards to budget this is king. (you can build anything if budget is no issue)
once you think you know what it will cost, double that number, now you are getting close. Take that original budget number and keep that much in reserve, i bet you will need it.
Many used quality parts are available here on the swap shop but time is required to find the right parts that work together to fit your objectives. Hodge podge performance parts buying gets expensive if they do not work together or changes in plans.
In reality most would be better off purchasing a good running swap out motor complete and rigged for a fixed price. Many here on oso all the time. Now you have your motor as a working spare. Mid season ship happens.
Just my .02 with .01 change
lots of luck and don’t be discouraged by the esoteric nay sayers.

Everybody's going to have an opinion on engine build none of are bad
Get yourself a good machine shop and a parts guy take it from there you could always come back and ask questions The only thing you have to consider is how you going to use this engine

Mercury racing made a couple engines, that you can look at for reference.

454 420HP engine.

This engine was

8.8:1 compression

GM rectangle port iron heads that received 2.25" intake valves and a custom valve job. The 365HP 454 mag used the same head, but had 2.19 valves, heads were as supplied from GM.

228/236 flat tappet camshaft, 530/551 lift 114LSA. Crane #132561 camshaft.

Roller rocker arms, 800CFM holley carb.

They also made a 440HP cyclone engine, which was the same as the above, however, it had a bit more aggressive camshaft. That camshaft was 231/239 110LSA with 550/558 lift. Also flat tappet.

Then there was the HP450 engine. This was a roller cam engine. This engine had a crane 169611 camshaft. 222/230 110LSA, with .576/.598 lift. Also got the GM rectangle ports with 2.25 intake valves, a single plane dart intake, and 830 Holley carb....8.8:1 compression.

Now, keep in mind, these 3 engines listed were all designed for a max rpm of around 5200RPM and run on 87 octane. If you are willing to spin the engines to say 5500-5800RPM, a little more camshaft, and a little more compression, and 500HP should not be a problem, even with those GM heads. Going to a set of aftermarket aluminum heads that are sized properly, with the right cam/compression combo, 93 octane, 575-600HP is within reach.

What's wrong with MSD?

I think I'm going to retire the silent choice. I would like a nice header style exhaust.

They die on a regular basis. Some people have great luck with no issues for years. Some others go through multiple boxes in a season. Other boxes have a lot more options for the same money or a little more.

What would be a good head? I was told the .088 heads would flow better then the pro comp 320 115 runners.

Here's a couple pics of what the distributors are known to do. Had it happen to me with a garage kept, 1 year old distributor:
http://i205.photobucket.com/albums/b...psaoe3xfcv.png
http://i205.photobucket.com/albums/b...psik5w8uij.png

Add to that, the fact that their CD boxes are well known to fail without warning.

Been there, no going again!

What do you recamened?

Any head is "good head"! :cartman:

That said, We don't ever mention the words "pro comp" on this board.

Call Bob and have him spec you an AFR head with hard annodizing and the proper valvetrain for what you decide to do.

Truth be told, a merc thunderbolt ignition would be fine.
If you want more flexibility in tuning your advance and want a rev limiter, the Daytona sensors CD box is the way to go.

Maybe guys with more experience will step up as I'm just a hobbyist.

There it is^^^^

not to get off topic but as far as MSD I have a short story to tell.... I had such a bad time with their boxes and soft touch limiters that I boxed it all up sent it all back with a note inside to please call me. I did get a return call asking me what needed to be done I told them to please keep them because they don't seem to work for me, he said they could fix them for a small charge, I told him no and to please just keep your junk, A. because in good conscience I could never sell them to anybody and B. I don't hate anyone bad enough to give them to!! never heard from them again. Understand this was just the electrical boxes not the distributors, I was using merc dist and still do.

you also have to buy and rig an MSD setup to replace the thunderbolt system you now have that is just as good and more durable...

Hey Whipper,

Let us hit the basics that we may be assuming but wrong on.

What boat and outdrive do you have ?

And, will you be able to use high octane every single time you get gas ? Every single time ? Every single time ? Yes I asked to twice to make sure you take this question seriously. Or could you possibly get stuck, even just once, getting 87 octane ?
Be truthful to yourself here.

pro comp or any other aftermarket head outflows 188-990-088. they (proconmp) have a rep for crappy castings and definatly are assembled with valves and springs, etc that don't belong in a marine engine. brodix-adfr-dart best alum heads. cost a lot more. merlin iron outflow stock GM's. decide your displacement-RPM range then start doing homework on the port size, cam, compression ratio and exhaust that is optimal for that setup. the 088 ports are really too big for the 365 mag engine they are delivered on. a smaller chambered large oval head would have been a better choice. too bad GM never did an oval with bigger valves. of course that is what most of the aftermarket heads are. aluminum upgrades of heavily ported 049 ovals. that being said i just bought a set of 088's. might get another.

I have a 94 Baja outlaw. Bravo 1. I use the highest octane at the pump.

Well. If there no good. Why did you buy 088 heads.

The 088 heads will not flow better than the pro comp. However, I would not recommend the pro comp heads due to their casting quality .

How fast do you want it to go???? It will take about 475hp to touch 70mph. Unless you have hydraulic steering, you really don't want to push it beyond 70.

91 octane then?????

Built right, you should be able to pull 475 on regular....

i didn't say they were no good. i said there was better. they fell in my lap for 200 bucks. better costs 2000 bucks on up. afr and brodix can run 2000 per head. even poirted-bigger valved iron ovals cost about 350 to 500 to buy and a 1500 porting-new valves machine shop bill. so factory rectangle heads at under 1000 a pair in runnable condition are usually the best bang for the buck but not the best bang...i have seen used edelbrocks show up on craigs for 1000. used procomps occasionally for 600. but craigslist is a crapshoot. and they are gone in one day.

It looks like that thing was stored in the ice melt bag!!

Self ventilating!

It would be worth calling Bob Madara at Marine Kinetics - 585-654-8583. He can offer you some very good info on cam and head selection, and he also can supply you with your parts at a price that is very hard to beat. I bought a set of AFR 265 heads from him for a little over $2k / pair already set up with the good roller springs and inconel exhaust valves (which are an absolute necessity on a performance marine engine). He can also custom design a cam for you that will be tailor made for your application.

You need to start by establishing a budget. Like others said, you may find that the $$ involved with setting up a set of stock iron heads for a good high lift roller cam will approach the cost of a set of new aluminum performance heads. The AFR 265's are about perfect for a 454 ci engine. You may find that Bob suggests a single plane intake over a dual plane intake for a performance marine engine. Not sure if there is a significant difference here if you already own an intake, but you want to run an oval port intake with the 265's (and optimally, port match them to the "roval" intake port shape.) DO NOT skimp on valvetrain components like pushrods, lifters, rockers, and springs. A stable valvetrain is perhaps the most critical factor in longevity of your marine engine. With the aluminum heads you can probably go a point higher on the CR. Piston choice might be a limiting factor here - flat tops on a 454 will probably only provide around 9.0:1 comp, but you need to calculate all of this before you select your pistons.

I will tell you that a 454 with the AFR 265's, a decent hyd roller in the .226 / .236* @ .050 / 112* LSA with around .610 lift should easily get you to better than 550 HP with the right intake, carb and exhaust. The tube headers are going to produce the best power, but you have to be careful about cracks in the tubes due to the design of them - they are under more structural load due to the long lever arm action of the primaries / collectors. A set of Stainless Marine would be ideal, and if you find a set of Gil's or something similar for a good deal, that would also work.

Regarding silent choice, it all ties into your goals for the boat, but if going for max power it will be a limiting factor for cam selection. As an example, I am running a set of Lightning headers on my 489 with AFR's and a relatively mild .226*/.230* / 114* LSA hyd roller cam, and I had reversion issues with silent choice attached to my headers. You wouldn't think this would happen, but my theory is that the aggressive cam profiles of the roller (which get the valve off the seat quicker than a flat tappet) combined with the efficient exhaust port and longer stroke came together in a "perfect reversion storm" for my application. I think it would be possible to design a high lift roller cam at a wider LSA angle and still run a good flowing manifold or header with a silent choice type exhaust without the reversion, but you are definitely trading off 15 or 20 HP on the top end to do this (just estimating here - Bob would be the man to ask). That is why you need to put pencil to paper and define your goals and budget, and then give Bob a call. Good luck with your build!

Unless I missed it here, what is your budget? As some have mentioned the AFR 265 head is the perfect head for a 454. I have built an engine around this head in the past, and I can speak with personal experience, is a great product. I ran my engine with 10.4:1 cr and had no issues at all running 91 octane gas. Budman II post above has a lot of great info in it. As he suggests call Bob Madera, he designed the engine I mentioned above. You cannot build a high horsepower 454 engine with 8.8 cr, at least not N/A.

My current engines are/were 8.8:1 with a decent sized cam (232/237) and they are pretty much done making power at 51-5200 rpms. Look at the merc hp 500, hp 450 or the 420's all are low compression and merc says to prop all of them at 5200 rpms. Which pretty much validates my experiences with my old builds. With the right cam and compression ratio, you can easily make 475 hp with the 088s. With the AFR 265 you can take that number to 550 or so. It just depends if you have the budget to buy new heads. Now if yours need to be rebuilt, buy all means buy the AFRs. I had $1000 in machine work, new seats, and guides in a set of old 188s. Plus I needed new springs, retainers and locks. When It was all said and done, I had close to $1500 into my iron heads. For $500 more I could have had new, modern heads.

Also- as some have already mentioned- stay away from MSD stuff. Buy a thunderbolt distributor with the Merc V-6 module and you will have a much more reliable ignition system as well as more money in your pocket, and you won't give up any performance.

Ramos48 here Rebuilt his 454 mags last year. Brodix 294 rect port race rite heads, mild hyd roller , a tad under 9:1 static, made 507hp at 5600rpm. 544ft lbs at 3800rpm. Can was 227/233 duration. This engine was not dead at 5200rpm.

That engine was not a low compression turd. Not bad for a low compression 87 octane build. It was not lacking low end torque. Not bad for a 454 with race rite rectangle heads and their standard non raised exhaust ports.