Thread: Best big block?

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hey ppl im a small block guy so bare with me. I am currently building a BBC race motor but i dont know which block to go dig out of the dirt. what cubic inch is the best? i was think 427,454,468,489,496,505 lol not quite sure what to do. obviously most of those are bored and stroked. i plan on doing a solid rotating assembly, shifting around 7000-9000rpm, brodix heads, proshot twin fogger 150-1000 hp nitrous kit. i dont want to go and buy a dart block or anything so i have to stick with stock blocks. let me hear some opinions. thanks.

buy a block you were doing good till you said 10.000 rpms and heavy nos

well 6500-7000 is more like rpm i guess and im prolly doin 400 hp kit.

big blocks dont do well with high RPMs, thats one of the benefits of smallblocks, longer the stroke on a motor, the harder it is to push it to high rpms... thats why those little hondas can rev so high..... you'll definately want all forged steel parts and even then i would say go with an aftermarket block... but if you're going to stick with a factory block, the 454s are supposed to be some really tough blocks...

ok that all makes sence. any suggestions for rpm then?

generally on big blocks 6000 is pretty much where you wanna go unless you're planning to spend a TON of money... you'll find that even then forged crank and rods and stuff wont be cheap... but you're going to want them.... if you wanna get gutsy you could probably push her to a 7000rpm build.... but thats gonna get a little risky

i have built many 454 468 -496 540-556-565-572+ big blocks is all i do and some stock stuff but i have been at big blocks for many years a stock big block with the rigth stuff can go to 6800 very easy . my car i have run it to 8000 rpm so big block engines can rpm like a small blocks. and have customers that shift at 7500 + with the bowtie blocks but the 400 hp shot is going to be hard on any thing .it has to be rigth but a 468 to 7000 would not be hard to do with out the nos what is why you need the better block than a stock type gm block but it could be done with one but why ? you would have 3/4 of the money in a stock 454 gm block that you can not bore out to 4.600 and will not take the beating like a dart or world would be up to it. you need a big bore to make good HP set of good heads to work. so go to 4.560 bore and you can not do that with the stock454 gm block

Theres a few good points here, but I have to ask a few questions. Why are you planning to attach a 150 shot of nitrous to a Big block motor? I guess if you plan to make a race motor, but what class do you plan to run in? There are rules to every class, such as displacement limits, induction, ect. Also, if you get into a series that allows it, a Blower/turbo is always an option. Granted, it gives away your game, but its always there. Finally, If your looking for higher R's, why not try a large-bore small block? Less work for higher R's. Just throwing it out there

Dave

A stock GM block will handle 725-750 h.p. with good caps, the block rocked to the bottom of the freeze plugs and studs.In the late 80's I use to run a 468 with dimple rods and a factory steel crank and heavy 13. to 1 TRW pistons.Rec. port heads every weekend.I would shift at 6,800.I could get one full season out of everything without having problems.With a light-weight 4340 roatating assembly 7,500 is very possible.Add aluminum rods and it will go 7,800-8,000.But keep in-mind the aluminum rods are used for one racing season and thrown away. Some time compare a BBC with a 460 ford.You soon see why most people prefer the BBC over the 460 for bracket racing.

stock block gm rods .trw piston. stock gm crank steel 0.040 on the rods 0.030 on the mains 7500 rpms on beaver road every day for over two years now in a mud truck still running stock caps two bolt main block. BUT what i have been trying to tell you is if you have a block great. but if you do not they go for $400-$500 for a two bolt block now you need to get good caps line bore time to drill for the caps wash the block check for cracks add block rock and studs ? and at this point you have over 3/4 of the money. or more then buying a good block that you can get some bore out of. yes a stock block can take it i have done it. many times. but for the nos shot why not put some more money down and get a block that you can go to 4.600 bore if some thing happens and can be sleeve the gm stock454 block can not.

I don't see why you need higher than 6,000 rpm.

A friend of mine works on drag boats. The alcohol BBC boat puts out 2500 HP at 5800 rpm and the Nitro-Methane Hemi boat 4500 HP at 5,200 rpm. The alcohol engine lasts an entire season while the NM engine is rebuilt every run.

Kitz

OOps, just noticed this is the bbchebbie forum, must mean the best bbc, not the best big block!!!!!

Originally posted by kitz
I don't see why you need higher than 6,000 rpm.

A friend of mine works on drag boats. The alcohol BBC boat puts out 2500 HP at 5800 rpm and the Nitro-Methane Hemi boat 4500 HP at 5,200 rpm. The alcohol engine lasts an entire season while the NM engine is rebuilt every run.

Kitz

oh and that would be a small bore gas engine stock 454 block? they do not compare. he said he wanted to put 150to1000 nos and run to 7000to10000 rpm. that dose not have any thing to do with nitro-methane or a heim in any way

Originally posted by Dave Severson
OOps, just noticed this is the bbchebbie forum, must mean the best bbc, not the best big block!!!!!

your are so funny

Originally posted by pat mccarthy
your are so funny

Well, Pat.... Got to get a shot at the chebbie guys whenever I can!!!!!