Thread: 468 build questions

Tweet

After conversing with Pat, i have come to the realization that my 468 will only check in around 9:1 at best. Original plan was to run the pistons that came with the 454 ( flat tops) .060 over block, zero decked with a .0039 gasket, 781 heads milled to 110cc's, stock crank and rods. This combo checks in just under 9:1 according to Summits CR Calculator. Keith Black sells a set of Hyper's with a -17cc dome for around $300 bucks ( good buy?). With just the change of piston it checks in at 10.35:1, sounds better right? Will I be okay on piston to head clearance, and will I still have a good Quench? I want to build this motor right the first time and I am def. going roller no matter what. Needs to run on 91 pump gas ( Oklahoma Crap, no 93 octane!!) looking for 500+ lbs throughout rpm range of like 2000-5000+. Don't really care about horses but would like to see at least 450. Any cam recommendations?? Was thinking of staying under .600 lift. What do you guys think? Would love to hear all Input, maybe Pat has some goodies he wants to get rid of? As of right now nothing has been done to anything, block is bored but pistons still sit .050 in the hole!! hasn't been decked and the heads cc'd at 110, installed 2.19/1.88 valves, no porting or gasket match.

well i do not care at all for the hyper s made by kb less its the only pistons you can get for the build and that not the case here . now there KB FHR are they way to go and about 100,more. nice piston for the money. or use the seal power hypers i have used solid rollers and new hyd rollers that can be for sale. seeing that i am burned up i need to sell some stuff will be off work for some time

Why do you prefer the sealed power to the kb? I'm assuming the FHR are forged pistons? What would you run as far as a hydrualic roller ( not really wanting to go mechanical). I just dont want to go to small, but I don't want to go to big either. If I'm running 10.35 CR I should be able to run a pretty decent sized cam, right? What kinda Hydrualics you have lying around there?

when do you really have to start worrying about piston to head clearance and piston to valve clearance? I'm assuming that dome is gonna come really close to smacking the head and not to mention the valves ( depending on cam specs.) I checked out those FHR and they are only 100 bucks more, they do look like a nice piston too. Then if I ever wanted to juice it i would have added insurance.

after many builds i like the hyper speed pros other then there now made in inda . you can use what you want.i am not going on here to make a list of why .i have done that in the past. yes the kb FHR are forged they are good pistons for the money . less a guy wants to pay for top line forged pistons. the cams i use in most builds are around the 625 lift and 238@050 i have two hyd listed on here for sale. so them are some of the size cams i use with some head work many things come in to play on the cam s. i use many and like any thing some things need to be check for fit. i would never say it a drop in and not at lest check one hole for fit . i spend a far amount of time checking and blue printing things tru decking .valve job .push rod size . cam specs .so things work the best .i can not speak for others who machine engines and build them with parts i say will fit and work the best when things will not be machined right or checked for size

Thanks Pat, I hope you get well soon. I'm leaning toward The Howards cam and lifter kits, hard to beat at $500 bucks. If anyone else has any input I would love to hear suggestions.

yep thats not a bad price for there roller kit 520.00 thats about dealer price for me on most cams with lifters . i have used most of Howards rollers cam till i went to Erson . if you get in to a steel core s 7/4 swap then your looking at a better core and a 4/7 swap so you can not get any thing that cheap . but i can sell the Erson new 4/7 i have with new Erson hyd roller lifters for $560

What exactly is the benefit of doing the 4/7 firing swap, and do you just switch the 4 with the 7 on your distributor?

Originally Posted by slammed84

What exactly is the benefit of doing the 4/7 firing swap, and do you just switch the 4 with the 7 on your distributor?

yep on the fire order 18736542broader smoother tq decrease crank deflection some say they run abit cooler just one of the 4/7 swap steel two pc core cams your looking at $350 just the cam

so what do you consider the threshold for running pump gas, as far as compression ratios go? I've always heard that 11:1 is about as high as you want to go with iron heads, but I've also heard that 11:1 is hard to run on pumpgas, keeping in mind the highest octane in Tulsa is 91. Unless you go to the speed shop and get 110 or whatever

well if your worry about it stay under 10.5 has abit to do with how big the cam is for your dynamic CR and if your quench is were it should be . but i not going to tell you what the most you can run on suspect fuel . i know i have some out there running very close to 11to1 with the one 4/7 cam . i tell every one to run 94 .i never hear any one say and thing. about ping. but if i know there not going to run good fuel or not willing to mix fuel or booster then there not getting much CR from a engine i build for them .BUT the bottom line is if they melt there pistons out and were not spending the money for fuel or not tune it in. it is not my problem

agreed. i'm think about keep it right around 10:1 or maybe a bit more. but not over 10.5:1. I read some big block build in some old magazines i have tonight and a similar combo made around 530 ft.lbs. and 460 hp. and that was at around 8.7 or 9 to one compression. didn;t say anything about the quench or details like that but I assuming with low compression that probably didnt zero deck the block and all that good stuff. Some I'm confident that I will be happy with my combo. My question is whether or not my 10 bolt will hold up to it? Is there anything i can do to beef it up to handle that power, or should i start thinking about a 12 bolt? not planning on running sticky tires until i can get a better rear end, but have you seen it done? Thanks for all your info man!!

well with any build were i mill the deck i shoot for o or 010 so the piston is O or in the hole 010 i try allways for a 038 head gasket most all the time . as for the 10 vs 12 .there are things you can do to beef up the 10 bolts .how long will it hold up with no work is hard to say places like DTS a Randys and other may help with parts your rear end may need or up grade . most all the car/truck rear ends stuff is all i ever played with street/hot rod and all out drag and them were ford 9s

Your plan is very similar to 2 454's I put together some time ago, one as a 462 and the other a .60 over 468. Similar on heads, etc. as yours. To gain a bit more compression I had my GM Perf heads, # 12363400 milled to 110 cc from stock 118. Oval port heads are probably better for the street use I do, but I used what I had. Regarding cams, after lunching two hydralic flat tappets over the past year, GO ROLLER! Pat cited some Erson roller tappet cams that merit some consideration. I replaced the cam in the 468 with a Comp Cam Thumpr middle cam for a Gen IV. I know you can do better with a Lunatti or Erson grind.
Right now I am looking for a 502 short block Gen VI with a build similar to what your looking to get out of your project. See what Pat recommends.
Good to see you're back and up and at em', Pat.......!

Originally Posted by emil

Your plan is very similar to 2 454's I put together some time ago, one as a 462 and the other a .60 over 468. Similar on heads, etc. as yours. To gain a bit more compression I had my GM Perf heads, # 12363400 milled to 110 cc from stock 118. Oval port heads are probably better for the street use I do, but I used what I had. Regarding cams, after lunching two hydralic flat tappets over the past year, GO ROLLER! Pat cited some Erson roller tappet cams that merit some consideration. I replaced the cam in the 468 with a Comp Cam Thumpr middle cam for a Gen IV. I know you can do better with a Lunatti or Erson grind.
Right now I am looking for a 502 short block Gen VI with a build similar to what your looking to get out of your project. See what Pat recommends.
Good to see you're back and up and at em', Pat.......!

Thanks for your reply, I am listening to Pat when he says stay away from Comp. I don't want the thumpr because they promote it solely for the sound, which goes against everything in my book. I'm thinking about Howards because they have cam and lifter combo's for around 500 bucks! Someone also told me to go solid, so thats crossing my mind as well. I have never had a solid cam so I'm unfamiliar with them, but I hear they are better for power and stability than Hydraulic cams. I know I would have to adjust more often. I still have to buy pistons, complete valvetrain so options are all over the place, can't decide.