gsxr1216

i acquired a HP500 carb roller cam for my 1990 Gen IV MAG 454 carbed motor but am nervous about reversion with the imco exhaust i got since i have silent choice also.

SO, i'm thinking about just replacing the stock flat tappet cam with something better so reversion wont be an issue and pick up some HP along the way, plus it will be more cost effective than going to the roller setup, any ideas on a good flat tappet cam to work with my stock heads intake ETC, basically the motor is bone stock except the imco powerflow exhaust.

thanks!

Griff

Crane #134241. The kit with lifters is Crane #134242. I used it in a 454mag and had Imco exhaust, but didn't have silent choice.

Another choice is the Crane #132561. It would have even less chance of reversion due to the 114 lob sep.

The power gains would be about the same from either one.

gsxr1216

any idea what kinds of gains would be had by that cam with everything else being stock?

thanks

mustangmark

I just put the Crane Cams 132561 in my 1989 454. It's a fairly small cam and has a 114 lobe Lobe Separation. I just got it running last weekend so it's only been through the cam break in and a 15 minute run on the water so far but I really like it a lot. Sounds good to! I posted a short video of it in q&a under "warlock running video" if you want to know how that cam sounds.

mustangmark

Also, I have very short risers on my motor and so far so good.....no reversion!

here's a pic
http://i986.photobucket.com/albums/a...ckrunning2.jpg

picklenjim

Very little. Probably loose power on the low end. That cam don't start work'n till 2800 rpm. Maybe pick up 2-3 mph.

MILD THUNDER

iTrader: (3)

Heres a real nice budget cam that i think would work real well for you. The price is right too.

http://www.northernautoparts.com/Pro...tModelId=15056

Griff

1-2mph/25hp or so. You should probably increase carb jetting a little bit as well.

The 132561 is the same cam that went into Merc 420's and 525SC's. With a Holley 800cfm carb and better intake, you should be right at 420hp

gsxr1216

thanks for the info!

gsxr1216

bringing this back to the top, i need some more info! my motor is all rebuilt on the bottom, new rings, fresh honed,polished crank, all new main/rod/cam bearings, ETC

i was looking into a custom roller cam setup and that looks like it wil put me in the close to $2000 range by the time i get the cam/lifters/pushrods/roller rockers/timing set, ETC, more money than i was hoping to spend.... so i need to cost out the full flat tappet setup so i can get a total cost for each direction and weigh the power to be had VS the money spent for each setup

seeing as i have stock 454 MAG gen IV, large rect port heads with imco powerflow exhaust with short risers for silent choice i'm a little limited on my cam options without reversion.

the cam Griff posted above ( the 420 cam, 132561) looks like it would probly be a good choice so far, but i'm open to other choice also. what do i need to run for lifters on these cams? i have heard the quality of lifters isnt what it used to be so i need a good lifter that wil break in good and serve me a long time without taking off a lobe, any sugestions?

pushrods, will my stock ones work fine with the bigger cam setup? they look fine for wear. if not, again, what would be a good "affordable" replacement.

rockers, my motor had the stamped steel ones on it OEM, I;m thinking of going roller rocker but is it worth it to upgrade to a roller rocker since i'm staying with a flat tappet cam? if so what a good affordable reliabe replacement?

springs, my stockers are shot so i need new springs no matter what route i go . if i go flat tappet cam like the 132651 whats a good spring package for it people have run? also do i need different valve retainers and locks to work with some of these new springs packages?

timing set, i need to go new there also for either setup, whats a good adjutstable timing set that holds up well over time?

thanks for the info all!