New 532 BBF need help with cam selection in z25

[eldridge173]

Hello,

my 89 Z25's 460 let go on me and i have replaced it with a 532 with aluminum heads. the motor did not come with a cam and im having the hardest time deciding between a roller cam set up or a flat tappet. I have heard horror stories about roller lifters not lasting, push rod angles not being correct and trashing the valve-train, and at the same time i've read horror stories where people are trashing flat tappet cams once a year.

so im really just looking for a couple opinions on what you would do, im completely open at this point as to which way to go flat tappet or roller.

the engine is brand new never started, with roller rockers, eldebrock intake, and will be running an 850 carb (most likely quick fuel).

thanks in advance for any help.

[22classic]

I say go roller, I have purchased quality stuff and haven't had a problem with my engines.

Best,
Matt

[eldridge173]

thanks for the input, is there a specific brand you have had luck out of or a brand to stay away from?

[gcarter]

I just did a quick search on the Comp site, but nothing for marine use listed.....
Maybe check w/Crane.
I think most of the major cam companies will build what you want, you might check w/both.

[TXDONZI]

http://www.460ford.com/

Signup on there and look around there are a few guys with marine experience. One guy is Paul Kane another is I believe The Mad Porter. Great place, Great guys and the only place to get Ford 385 series BBF help and advice.

[eldridge173]

Thanks for the advice, I signed up yesterday. I actually ended up buying a full roller set up and i found a great engine shop in Concord, NC which isn't too far from me. im am having him break in the engine and tune it on the dyno over the next few weeks. this guy is set on having me run the 750 Holley that came off my old dead 460, which doesn't sound like enough carb for that big motor...............but i guess we will see on the dyno.

the engine builder claimed with a roller cam and 850 carb these engine consistently produce 650hp/700tq every time he dynos one he builds, so i guess ill be able to call his bluff if it doesn't. ill post up the results.

[Pat McPherson]

I have a 750 on my stock 435HP 502 and I know Merc ran 800 on 500HP 502.
I have a bud that runs a 950cfm on a 600HP 509 but that's up to 6000rpm.

I think your engine will need more flow than 750cfm above 46-4700rpm.

[gcarter]

I agree, I seemed to be running out of air w/my 509 BBC (800 CFM Holley), a member recommended I contact
Patrick James @ Pro Products Racing Carbs (727-490-5717) who built a 950 custom carb built specifically for
my engine that would flow at least 840 CFM. It seems Holley's nomenclature isn't very accurate. I've only run it
a couple of times and have picked up over 200 RPM..

[HallJ]

Tell us about the exhaust you will be using.

Jeff

[eldridge173]

Everyone thanks for the advice and help

On the carb i was thinking the exact same thing................i wont argue with you one bit. This guy swears he can make the 750 work excellent so i figured ill give him a shot, and he even offered to throw one of his 850's on it on the dyno to show me the comparison between the two. In the long run of things if it needs a bigger carb ill get a bigger carb. Truth be told this is way more motor than i need, so if the 750 operates fine just holds back a few ponies i would be ok with it, but it its going to be an operational issue i wont have that.

The exhaust is just the factory through hull exhaust, the heads (i forgot the make) are made to work with OEM BBF exhaust manifold. also it will be dyno tuned with the exhaust im using hopefully with in the next two weeks. If you want take a look at the guys website im getting the cam, lifters, rockers and pushrods from, he is also the one dynoing tuning it. the owner of the company is a friend of a friend and he built and tuned my fiends 460 in a spectra and it runs fantastic. i wish i could say my engine was built by him, but unfortunately it wasn't, it came out of a separate company in CA.
here is his companies website.
https://prestigemoto.com/

Honestly what im really looking for here is a little more power than my old worn out 28 year old 900hr 460, and a turn key reliability is the big ticket for me.......well as much as a carb'd big block will allow anyway. I love this boat its smooth, looks great, sounds great, and it turns heads, so if I can get her to operate as good as she looks ill be all smiles!! i spend 2-3 days a week on the local lake on my boat, and with the Donzi down our 28ft regal and seadoo just aren't cutting it :rolleyes:.

[BUIZILLA]

the 460 head on a 532 has some decent intake port volume, it NEEDS food... with that said *I* would think a 950 would be more efficient overall and respond better to jetting/mixture changes :pimp:

[gcarter]

I was wondering if you were aware of these exhaust manifolds by Hardin:

http://www.hardin-marine.com/c-1344-460-ford-manifolds.aspx

These manifolds have been the "go to" manifolds for BBC's for many years.
Originally supplied by Gil until they failed during the recession, Hardin has
added these BBF manifolds, which has the same port spacing as BBC's but
a different bolt pattern. These manifolds substantially outperform the old
OMC exhaust manifolds.

[eldridge173]

well now...........sounds like i will need a bigger carb, there is new in the box dominator 1050 on my local craigslist for $450, should i look into that or is that too big.

Carter,

I really like the hardin marine stuff. i had it on my 1966 skisporter's 408 stroker, and on my 77 Spectra day cruiser's 460 which got stolen off the boat in winter storage:mad:.

anyway i am a big fan of them, and when the time comes and these oldie goldie OMC's are toast ill have a set!

so im sure as you guys can tell from those Three dreadful letters my boat is equipped with the dreaded OMC Baby King (dog clutch, shift in lower unit) out drive. unluckily but luckily at the same time when i first got the boat 6 months ago the drive exploded on me, admittedly it had no oil in it and it was totally my fault. luckily i found a local older gentleman who is an OMC expert and he was able to rebuild my drive and alight the shifter cable properly and now it is a properly working drive. i guess my question here is, how long do you think she will hold up? i do not drive my boat like an idiot, we do not ski behind it, i just cruise with her at the end of the day its a 28 year old boat im restoring not a beater to me.

[yeller]

well now...........sounds like i will need a bigger carb, there is new in the box dominator 1050 on my local craigslist for $450, should i look into that or is that too big.

No offence to anyone, just my 2 cents, but the engine builder that you wish built your motor, and the engine builder that is going to dyno your engine swears he can make the 750 work....and he is willing to install a bigger carb just to show you it's not going to work any better.

I realize others have given you their experience with what worked for them, but I'd wait to see how well the engine builder can make the 750 work. If he can't make it work and you need a bigger carb, you can buy one then, but I'd go with what the engine builder suggests first.

[eldridge173]

fair enough and im definitely going to give it a shot on the dyno

[eldridge173]

it took me for ever to locate this thread, figure out my username and password......and 3 years of fighting to finally hear this thing run, so now that i have id like to share my Nightmare/story/learning experience with every one.

so little back story, i bought the "marine" 532 new off eBay that was supposed to have been built with brand name parts buy a guy in businesses for 50 years. it was junk! got it to NC to the proper engine builder the did some test and immediately called me saying im not even willing to start this engine. valve springs were no where near what was needed for a motor like this, compression was scattered, Chinese no name parts all through the motor, complete junk literally had to beg the guy into working on it at this point. he fixed the head so the valves would seal, new rings on the Chinese pistons (couple broken on a never ran engine), and got it on the dyno......made zero power, spit the rear main seal in minutes. pulled it off cleaned the oil flooded dyno lab up, right fully so gave me an earful. did a leak down test, compression test and all was good to his surprise. had a one piece rear main seal made put it back together and boom same issue trashed the seal in minutes made zero power. pulled the engine apart checked absolutely every thing, all checked out, put new pistons and rings in it just for the sake of it, all new gaskets again.......back to the dyno and same result in minutes.

he calls and goes look im not going to charge you the shop fee for all this labor and dyno time, but here are your options. A come pick this up and call it a loss i cant help you. or B lets start with a new block and new crank and ill eat the labor on properly machining it myself and just charge you for parts and dyno time. so i went with that a month goes by he calls and says it runs perfect, little bit of cavitation in the oil pan at WFO being a stroker, but safe oil pressure and great power across the board.. i forgot the exact power figures as this was a year ago now, but the one thing i do remember even after we intentionally choked up the engine is at 2800 rpms on a Brawler 750 carb it did make 597 foot pounds of torque and still climbing.

so fast forward i had issues with my mechanic i had paid to swap the engine, seemed i could never get our schedules lined up to drop off the engine. i offered to pay friends, so one day is literally said F'it its going somewhere this week or im scrapping this boat and selling the drive, engine, and trailer this weekend. so low and behold i saw a craigslist add advertising OMC Propellers which i needed and i called the guy, turned out to be the best most honest and educated boat mechanic i've ever encountered and next thing i knew i get a call yesterday asking if i wanted to hear it run. i had told him i had the engine built professionally and not spared a penny. he said " i finally got the cut up wiring figured out, power to the fuel pump and i bumped the starter to see what would happen and i've never heard an engine sound like the explosion of noise it made when it fired up" he told me when i got there he thought i was exaggerating one what quality of parts i used and who built the motor and when it fired it scared the hell out of him lol which made me smile.

so yesterday after work i headed over to his shop and heard her fire for the first time in three years and i was so happy. dont get me wrong its not a 800hp fire breathing dragon, but compared to a production engine the sound of this thing is just obnoxious you feel every time a cylinder fires in your chest when you are behind it.

At the end of the engine disaster it ended up as a 532 with a scat rotation assy, wiseco pistons, completely custom full roller set up, aluminum heads, all ARP hardware, high end balancer, double roller timing set, and some other goodies i just dont remember. we did internationally choke up the engine with a 750 carb, and edlebrock performer intake that has some pretty short intake runners, and running the stock OMC manifolds to pro long the short life expectancy of the out drive.

anyway moral of the story, dont buy a motor off ebay, dont use cheap parts, and if your engine builder doesn't have a very well known presence in the engine world id look elsewhere. OH yes one more thing guess what deteriorated after sitting for 3 years under a cover?? any guesses? up the interior is trashed!! so thats the new project:shocking:

pics/video to follow, enjoy!

[eldridge173]

first start, super rich

[eldridge173]

second run, high idle around 1k RPMS

[yeller]

That sucks. It does sound nice though.

I've always liked that model of Donzi.

[eldridge173]

i finally put her in the water, didn't check the out drive like an idiot and it had zero oil in in it so it exploded in 5 minutes, next week had a out drive installed and she worked perfectly! sounded incredible and for the most part was pretty spot on.