What is the most HP an Olds can make with stock heads

[455maveric]

first what are the best head are they C,A,KA or what and what is the bigest valves that can be instaled . Second what is the most HP that can be made with unported heads. third how fast will it be in a sleekcraft aristocrat with dropsnoot and jetovator and ride plate. I want to change the engine but for right now i want to go out on the lake and have some fun

[boatermike]

should be able to make enough power to get out and have fun. seems like 500 hp isnt hard to achieve but beyond that its tough. 50 mph is way more fun than not boating at all.

[455maveric]

i hope it would do more than 50 with 500 HP but the boat might be a big fat pig but it will be a prety pig

[OldSleekOlds]

These guys can give you a better answer to your Olds head question than most other guys. I think the "C" or "K" heads will get you the biggest valves. http://72.22.90.30/phpBB2/index.php?sid=ef5b9c1af5669a39ad6f159cee4c7be9

Which Aristocrat do you have? I have a 1976 Aristocrat tunnel with a 455 (462) Olds. They made the Aristocrat with either a tunnel or "V" bottom. Mine came with a Jacuzzi YJ pump. I did a conversion to an Aggressor pump with a Place Diverter. The pump intake is the original Jacuzzi that I reworked by machining it and adding a shoe and ride plate (I have a machine shop). I had a Droop Snoot on it but took it off because the boat goes better without the Droop. Maybe a straight Snoot would help, I never tried one.

I did a lot of work on the 455. It looks like this........

455 .....030 over = 462
Balanced rotating assy
Forged pistons 10.25:1
Edelbrock heads with extra porting
Harlandsharp rockers
Performer intake
Holly 930 cfm Marine carb
10 qt. oil pan
Restricters including push rods
Outside oil returns from rear of heads to pan
MSD ignition w/billet dist

Hardin log exhaust

I can supply cam specs and Dyno sheet if you want to see them.

The important part is the fact that with the help of 2 friends who have been building high perf. Marine engines for many, many years we could not quite get 500 hp. We made cam, carb, and intake changes. One of the friends has a Dyno in his shop. We tinkered with it on the Dyno for nearly 2 weeks. Taking the Performer intake off and installing a (port matched) new Victor intake actually lost more than 30 hp. The problem is the "Log" exhaust system. All of the Dyno pulls were with the exhaust system from the boat. RELIABLE sources tell me that the log exhaust was costing about 100 hp. The 2 guys working with me on it agreed.

What will you have for an exhaust system?

Unless you have a "good" exhaust system, you will have a hard time getting 500 hp out of your Olds.

[455maveric]

I have the V bottom it has a berk JE pump but i had a 2 piece bowl and a droop so i put them on with the jetovator i can lose the engine cover and go to thru transom headers

[OldSleekOlds]

I gotta think anything would be better than logs.

[boatermike]

i wonder if there are any gains if ya keep the logs but ditch the snails for over transom tailpipes

[boatermike]

5 ponies might go 70?

[boatermike]

stock tame would be better than nothing

[Raceman]

The absolutely positively BEST intake for a 455 olds is the old Edelbrock Torker. That's surprising because I don't think they're worth a crap for a big block Chevy. They're long since discontinued, but still relatively common on E Bay. Some of the dyno tests I've read in the mags claim 30 HP increase JUST FROM this intake over any of the other dual plane alum. intakes that are available. I've got an Offenhauser with 2 4's on my 455, but it's because I like the way it looks and it probably COSTS 30 or 40 HP. One of the mags............. Popular Hotrodding MAYBE has an olds buildup in this month's addition. Edlebrock heads, even stock, seem to be a big bang for the buck (under 2K from Summit)

[Hamjet]

first what are the best head are they C,A,KA or what and what is the bigest valves that can be instaled . Second what is the most HP that can be made with unported heads. third how fast will it be in a sleekcraft aristocrat with dropsnoot and jetovator and ride plate. I want to change the engine but for right now i want to go out on the lake and have some fun

C,Ca and Ka heads are all big valve units. "A" heads I think are SBO units. The "C" &"Ca" heads flows the best in stock form as for the "Ka" units the two centre exhaust ports are not blocked off and drains hp.

IMHO in stock form you will be lucky if you get bejond 300Hp and that is with a good pump setup. 50-55mph on a good day.

It is fairly easy to check estimated hp by using your impeller chart (Berkeley).

If you know your impeller cut, let us say "A" and you know your RPM, you can calculate the hp range of your engine.

"A" impeller @ 4250 RPM will probably give you about 220-250HP for example.( above 4500 RPM they don't live long without special mods)

To get it to the 400-450HP range you are going to have to throw a wheelbarrow of $ at it, beyond 450-700HP a dumptruck full of $.

Wikus

[OldSleekOlds]

C,Ca and Ka heads are all big valve units. "A" heads I think are SBO units. The "C" &"Ca" heads flows the best in stock form as for the "Ka" units the two centre exhaust ports are not blocked off and drains hp.

IMHO in stock form you will be lucky if you get bejond 300Hp and that is with a good pump setup. 50-55mph on a good day.

It is fairly easy to check estimated hp by using your impeller chart (Berkeley).

If you know your impeller cut, let us say "A" and you know your RPM, you can calculate the hp range of your engine.

"A" impeller @ 4250 RPM will probably give you about 220-250HP for example.( above 4500 RPM they don't live long without special mods)

To get it to the 400-450HP range you are going to have to throw a wheelbarrow of $ at it, beyond 450-700HP a dumptruck full of $.

Wikus

I agree completely.

Old

[455maveric]

Wow thought the stock W30 engine had 370 HP

[boatermike]

wasnt there even a 385 hp rating?

[boatermike]

in fact weren't these ratings on the low side?seems like 500 would be there with carb intake headers and cam?

[wriedt1]

If you plan on doing another motor later just rebuild your 455 stock once you start changing HP you run into oiling problems look at my threads and you will see what issues I've had. The C heads are the best cast head to use they all have crossovers that rob HP but the C head has the best port

[OldSleekOlds]

wasnt there even a 385 hp rating?

The kind of numbers you're talking about are here http://www.442.com/tech/tech.html

There are a couple problems with the motor in a boat. The best "wet" exhaust system is not near as good as a good set of automotive headers. Without a good exhaust system, nothing else is going to work very well. Lots of guys will tell you how great a particular setup works for a 455 Olds. This should immediately raise the question "Is it in a boat?". Mondello was giving me really great advice until I asked if this will work in a boat. They had to go and ask the old man (Joe Mondello) who was retired. The old man said NO it won't work in a boat. The stuff they were telling me was great for a drag racing motor. A motor that could make lots of power for a minute or so on a dragstrip wasn't going to help me at all. Most of the boaters I know want a motor that will run on "pump gas" and make lots of power. That's hard to do. It's real hard to do without spending a ton of money.

For example, an Edelbrock Victor intake works great on a car. Even after a cam change, my motor made 30+ hp LESS than it did with an Edelbrock Performer. The restrictive exhaust kills the performance. Car guys don't have that kind of problem and they usually don't understand why what works in a car don't work in a boat.

[boatermike]

yes i want headers....lol

[Hamjet]

Start by identifying your engine, the engine number is on the left hand side of the engine(driver side) stamped just under the front of the forward exhaust port. Compare the engine nr. to the list that you can find at (http://www.442.com/oldsfaq/ofeng.htm#Engines) If you have an "M" in the number it means that you have an irragation/marine block/engine. I have 2 of these blocks and after hours of comparing them to a normal engine block I only found a couple of differances.

The cams that were used in the "M" blocks were from the higher HP motors. Heads were normally Ga, Ca or Ka.

Clearances on the engines were also a bit looser than the automotive versions. The crank castings normally are "N" which means it is a nodular crank and good to have.

Wikus

[Hamjet]

The kind of numbers you're talking about are here http://www.442.com/tech/tech.html

There are a couple problems with the motor in a boat. The best "wet" exhaust system is not near as good as a good set of automotive headers. Without a good exhaust system, nothing else is going to work very well. Lots of guys will tell you how great a particular setup works for a 455 Olds. This should immediately raise the question "Is it in a boat?". Mondello was giving me really great advice until I asked if this will work in a boat. They had to go and ask the old man (Joe Mondello) who was retired. The old man said NO it won't work in a boat. The stuff they were telling me was great for a drag racing motor. A motor that could make lots of power for a minute or so on a dragstrip wasn't going to help me at all. Most of the boaters I know want a motor that will run on "pump gas" and make lots of power. That's hard to do. It's real hard to do without spending a ton of money.

For example, an Edelbrock Victor intake works great on a car. Even after a cam change, my motor made 30+ hp LESS than it did with an Edelbrock Performer. The restrictive exhaust kills the performance. Car guys don't have that kind of problem and they usually don't understand why what works in a car don't work in a boat.

x2, The performance paramaters are different, if i can put it that way.

[455maveric]

I looked at the engine before i know it comes out of a mid 70's car with the J heads thats one reason i am asking about heads i know the ones i have suck . so it looks like i should use C casting heads and some TT Headers and like a prefomer RPM intake if they make such a beast. have any of you tried this crosswind intake that summit sells looks like an air gap http://www.summitracing.com/parts/PFS-57025/?rtype=10

[Hamjet]

You must select a intake manifold that will suit your application. Do you want torque through the whole rev range, high rpm etc. Invest in a good cam, but be careful as to the lift on the stock lifters and valve springs.

Certain manifolds only start working at a certain rev range ie. Victor from 5500rpm and above, Torker and Performer RPM from 2500RPM-6000RPM etc.

Have a look at the link i provided.

Wikus

http://www.cpperformance.com/c-317-oldsmobile-455.aspx

[455maveric]

that crosswind intake said from 1500 to 6500 RPM so i think i will go with that and i will keep my eyes open for a set of heads but it will be a while before i get them i will start with the intake . I gota get all settled in at my new job and appartment

[TIMINATOR]

Crosswind best on boat at boat rpm, 850+ carb. Torker only if you HAVE one, then with porting/blending and 1" carb spacer. There are two sized logs and two sizes of snails, OT pipes are better than any snails. Bassets for max HP. Reread the article or wait for the CD. TIMINATOR

[455maveric]

I see they offer the crosswind with injector bosses has anyone gone to electronic fuel injection on a Olds or even a BBC and do you like it

[TIMINATOR]

EFI despite all of the promises, typically won't make any more power than a properly sized and tuned(jetting, timing, etc) carb setup. Most gains are in ultra lean smog circumstances and driveability issues. I live in the Phoenix,AZ. area, we boat all year long and I don't think I even know anyone that runs a choke on their boats or performance street cars. The Crosswind bosses are used for fogger N2O nozzles. I have a FAST technologies setup for my 598 BBC to run the Crower stack setup, or on my pro street Nova, but I haven't cared enough about it. I will probably run the FAST or my Megasquirt on my roadster with the 300HP Northstar in it when finished, unless I can find a used carb setup for it too! I have a Latham axial flow blower that I am converting to dual sidedraft Webers, so you see where my heart lies. P.S. I have installed,dynoed and owned EFI factory and aftermarket stuff. I machine and build performance engines at my shop for a living, and when anyone wants to do EFI on a car or boat, I point to one of my, or pics of my customers, blown boats or cars and point out that the end cost will be close to the same. Which one would you rather own? The last EFI questioning guy went with a 4 Weber crossram setup. I can post pics if anybody cares. He stated:"You can go to any car gathering and see stock and aftermarket EFI. When was the last time that you saw one of these? Same price, waaaay cooler". I agree. TIMINATOR