Projects Budget 400 SBC combination

Starting to drift away from the budget origins of the thread here but on a "budget" cubes usually rule the roost. Being a open wheel racer I like the harmonic longevity of big bore short stroke. Whatever you like, dirt or pavement , basically If you can't hook it up you loose. Each crankshaft stroke combo has a particular application it is suited for in its mechanical life. For cheapest fun I'd slip together a claimer style flat top 4.125 ish x 3.750 stroke 5.7 rod 400 you'll be plenty happy w the power. Probably the cheapest little monster combo for the buck. On street cubic inches are a ok! If we all liked the same stuff it'd be a pretty boring world! I guess that's why there's blondes, brunettes & red heads ! But I like all the stuff here on the hamb! Flux

 

My l79 cammed 327 10.4 to 1 compression iron head daily runs fine on 92 octane, so that's something to add to the debate, similar specs on a 400 would haul!

 

A lot of guys are looking for those heads! The one's that end in "062" or "906" are the one's you want.

 

If you do the math a 400 block bored .030 with a 327 crank comes out to 353 cubic inches. Also remember using a 350 or 327 crankshaft you will need to buy bearing spacers and with vortec heads you will need a vortec style manifold and also need to drill them for steam holes.

 

You could also do a mutt involving a 283 crank, imagine the rpms that'd pull. Pistons aint gunna be cheap, but a while back speedway clearanced a bunch of oddball piston sets for destroked 400's. If you had been there you coulda build something reasonable

 

So we are pretty much all in agreeance that the vortec heads + current cam will not equal my goal of affordable 450 hp.
2old2fast- Point taken, I've started to look into aftermarket heads however my budget is forcing me to look for them used. Right now I'm seeing quite a few Brodix and Scorpion heads that might be do able if I find one for a decent price.
Porknbeaner- You have no idea how bad I want a 377, but I just don't think a T-5 will live long with me behind the wheel of both of us. Besides, It really wouldn't be a budget build going for a 377. I'll take your world for it and look for a cam that will provide more lift on the intake and exhaust to compliment the larger intake and exhaust ports on the aftermarket heads.
Steinauge- Thanks for the setup, do you think you could of gotten 50 more horsepower out of those heads or where they flowing as much as they could without being ported?
Joecool- I didn't know you took that much into consideration with the cam shaft. I've only taken, heads, crank weight, piston weight, connecting rod weight, intended rpm driving range, etc. Basically I've kept my calculations strickly to the engine.
Flux Capacitor- Hearing you loud and clear, 5.7 rods and claimer pistons are on the books. The valve reliefs should lower my compression a little and give me some safety from detonation. I'm glad I'm not the only one staring at my pile of parts and going hmm.... I truly hope I've got a good 400 block myself, if not then I'm really gonna go lsx from a truck or something.
Gearheads QCE- Thanks for the reciepe, Super Chevy swap meet is coming to my area soon so I'll be on the look out for some heads and maybe a cam if I don't find a deal on ebay or craigslist first.
Speed Gems- Yep I've though of that, it wouldn't live long without a strong radiator and oil system but the rpms...
Shaggy- 8000rpms would be competely doable with that setup.

So, 5.7 rods, claimer pistons with 2 valve reliefs, aftermarket heads, and a cam to support them is looking to be the requirement to reach 450 from what I'm seeing.

 

I did the math :

I rounded down instead of up and either way it does not come out to 348 as someone else suggested.

You may also have to drill the block depending on which 400 block you have and I suggest originally a better set of heads

I just happen to have a better set of heads here that I would use if I were building the mill and they came with steam holes and a template for drilling the block if the block did not have steam holes.

yes if he uses anything but a 400 crank he will need bearing spacers unless he just happens onto a set of federal mogul thick bearings for the swap. I know that they no longer make them but there are still some out there and with the internet they could possibly be located. Either way people have been putting large journal small block cranks on 400s for a long time, a lot of them were done by people not nearly as smart as you and me.

dragoon119 I never suggested that you build a 377 I suggested a 350 (actually a 352 and change) which I knew when I suggested it that you would never do. You are shooting for a goal of 450 horse and my suggestions were for a way to more easily achieve that goal.

be careful with Brodix heads, they come in various valve angles and what you want are 23 degree heads. 18 degree are common and they will not accept a stock intake, the mating surface is also canted and not just the valves. And we currently have a pair of 15 degree heads that take yet another unobtainable intake. Anyway be sure that your new/different heads will work with common GM components if you want to keep your budget reasonable.

By the way in a smaller displacement mill that cam that you have would make a nice healthy street cam and that is something you should be aware of when you are peddling it. Crower was one of the sponsors of a car I was tuning in the '70s and they make a fine cam shaft.

 

????? please explain .. use little words, I am just a stupid engine builder.

 

I'll try ... when you use a 6" rod , you push the pin up into the oil ring, some say this causes increased oil consumption ..... I have 6" rods in my 388 stroker & am experiencing no ill effects
dave

 

The oil consumption should be easy enough to control on a naturally aspirated motor.

There is a lot of theory behind longer rods, the one most leaned on would only be of much benefit on a street motor and Joe is a racer by nature.

They say that a longer rod increases your dwell time, that being the nanoseconds that the piston idles on changeover. That would be at both ends of the stroke, but the important end would be on top. A longer dwell time in turn amounts to better burn and in theory decreases your fuel requirement. IE you can run on lower octane fuel. I have seen it put to practice on a short stroke 350 but the engine in question was running aluminum heads and I imagine that the heads did as much as the increased dwell time. I think in this instance it is one of those things that works better on paper than in practice. I don't think that you can really gain enough benefit from the rods alone to make a difference in what fuel you are running.

The longer rods also changes your rod angle enough to free up a little torque, but that could also be attained by moving your pin location. So theoretically it becomes a moot point.

Now in Joe's case he could actually achieve greater benefit from shorter rods than just oil control. Again we are talking about going very fast for a short distance. When you increase your stroke to rod ratio you also increase port velocity. I have no idea why, that is a question for a physicist, but I do know that it works.

Now keeping in mind that Joe is going really fast from point A to point B, he does create greater crank case pressures that most of us, given that we are not running our motors worn slap out. Crankcase pressure creates ring flutter and so on and so forth. So by keeping his rings more stable and creating greater port velocity he has benefitted twice from running the shorter rods.

Anyway enough theory for one day. All of that and a buck will get you coffee at micky Ds.

 

I should mention that my reason to run 6" rods was that I could have an internally bal. stroker w/o the need for $$$$$ heavy metal balancing , not sure if that would apply to a 400 but I' guess it would [w/an aftermarket crank]
dave

 

I just don't like crowding the rings toward the top of the piston. 6 inch rods are usually heavier than a 5.7 so that is a small but important consideration.I think that also out weighs the longer dwell time theory .The pistons may or may not be different weight, depending on brand name.I do not do things like other people ,so I'm probably not the guy to follow.
As far as setting things up ,I think the success of any Hot Rod venture is the correct combination ,thats it period .I have seen to many rodders put cars together with what they have instead of what they need, and they are almost always dissappointed. just my opinion

 

I think that the cost of rods and pistons outweighs the price of Mallory metal too.

 

Beaner, were on the HAMB ,money means nothing to us traditional guys.

 

It must not or we would have some.

 

AHHHH grasshopper....with the longer rod, the piston dwell is SHORTER @ BDC...and LONGER @ TDC. The opposite is true with the shorter rod. I've been to several of smokey Yunick's seminars. Didn't actually get the long rod deal, until I was eating breakfast with him, and he replicated the rod ratio thing on the table cloth with a fork,and some cups Now that guy was a genius.
Been to several AETC conferences too(advanced engine technology conference) , as well as help write one seminar on honing. I guess I don't see the ring package as a problem. Shorter, lighter pistons, and better thrust angle on piston,as well as better cylinder fill, all advantages from the longer rod. and it doesn't have to be a pricey 6" rod, even a 350 rod is better than the 400 rod. but will need to be clearanced to clear the cam, as the bolts are longer.
Just my opinion. but again , my opinion is not always correct..

 

Keeping a budget in mind as the basis for this build, there's no need to use anything but the factory bottom end parts along with a decent forged flat top piston.

A set of World Products iron heads straight out of the box, either the SR or Sportsman heads would do the job and they're cheaper or the same price as having a set of stock heads properly reworked.

Choose the cam that best suits your combo, no need to twist this much higher than 5,000 RPM with a 5,500 RPM max to make plenty of power.

Use the cubic inches to your advantage, there is no need to do anything exotic with different stroke cranks or longer rods.

Keep focused on your budget and use the 400 Chevy for its intended purpose, big cubes in a small package that won't need to be revved to the moon to make good power.

 

I too am a proponent of "long rod" piston dwell at the top of the cylinder walls & have used ring land spacers in stroked sbc's with the spacers literally setting up living quarters in the wrist pins bedroom. No apparent ring seal or cylinder wear problems. I've always thought Mopar R&D discovered the gains of a long rod before the others when they revamped their engine program in the early 60's evident in their wedge B,RB & small LA series motors. Never seen any of those engines that were a slouch. I love mix matching parts as much as anybody but just do what ever makes you happy. To me as the stroke goes down & with it the pin height The Pistons start looking kinda H Farmall ish. I do love the 370 ish combo's kinda like shifting the ideal little 327 up a notch in bore & stroke. N I'm a middle aged dirt tracker. Budget can be a wirtydird with a champaign taste on a beer budget! Flux

 

keeping up on the thread here..... This FIRST statement ,as well as the Rest, should be a given. I understand the budget thing and all,but good/quality parts are at fingertips,and well,longevity? Pop for some forgings ,your wallet,and peace of mind will be at ease.....You want to step down and last? Heed Draggin's words.......

 

Did one of those but used 6.250 rods it lets you use off the shelf 400 6 inch rod pistons. Like Smokey said when ask about rods use the longest that will fit.

 

Flux (&Tricky)

In my post I did say that the dwell was longer at the top of the stroke and that there was or theoretically shpuld be benefit from that. I also mentioned that it would be an unmeasurable benefit in the line of HP or torque gain or octane requirements. In one of our motors you cannot gain enough rod length to be able to measure the benefit. At least not with any equipment that any of us (including Smokey who I never said was not intelligent) would have access to so we have only mathematical equation and theoretical physics to rely on. I do have a rudimentary understanding of physics, it was part of my field of study when I was studying for my design degree and I can probably hang with any but the best that the HAMB has to offer but end of the day if you cannot measure a benefit you cannot really claim it and you certainly don't gain much benefit from the claimed lessened octane requirement if it comes down to the .1-.001 of a percent range.

I am not sure where helping with a honing seminar even falls into the argument and while I have not had breakfast with Smokey I did have hot dogs with him, although the discussion was more about the race at hand and mention of his hot gas engine. Well that and the fact that I had name dropped to get into the pits, and he had come to my rescue even though he had no clue as to who I was.

Anyway name dropping aside, the fact that I had lunch with Mr Yunic does not make me him anyway now does it.

My mention of oil consumption was in reference to Joe's concern. When I said it was easy to overcome on a naturally aspirated street engine; I was talking about the fact that a naturally aspirated street engine is not as likely to develop the crankcase pressures of say a force fed race engine or even a naturally aspirated race engine. A concern for a lot of racers is the weakness or lack of support of the oil ring when it passes through the wrist pin hole. What a lot of engine builders call wring flutter would be increased when the ring is not properly supported. It is commonly believed that crank case pressure is one of the primary causes of ring flutter, along with friction and harmonics. I used crankcase pressure just because it is more easily measured with tools that any of us can or do have at our disposal. Most of you will not be willing to go through the trouble but a simple vacuum pump can be used to do away with the problem and the requirements on a cruiser engine would not be as heavy as those of a blown alchy burner.

Chrysler did work with long rod technology in the '60s as well as raising the deck height. By raising the deck height one of the problems overcome on the long rod motors was getting the wrist pin into the ring lands. They could use a cheaper or more common piston. All of this is a moot point as we are working on a budget build on this thread so a raised deck block is going to be out of the question.

I have for a long time tossed around the idea of using a plate with a head gasket on both sides to raise the deck height of a low deck block. I think that it has already been done and it could in theory be a low budget way to get a raised deck block or a raised deck block where one is not mass produced. Probably not really practical but there is an idea for a young guy to make his fortune in the hot rod industry, no charge for the idea.

I did work for a while with a guy in Nor Cal who was developing buttons to go in the wrist pin hole for pistons that the wrist pin got into the ring lands. I am guessing that this is what flux is talking about when he is talking about ring land spacers. He said he was on contract to Kieth Black and all I did was machine work for him on a contract labor basis so I am sure that what I did was moot as well. That and I have learned that people will say about anything, and all I cared about was getting paid anyway. He could have been working with Gerald Hopkins for all I cared. The plug constituted shortening up the wrist pin and the plug became the keeper as well as the spacer for the rings. As I recall he beefed up the wrist pin boss to allow for the shortened wrist pin which in turn meant that he had to loose some weight somewhere else. All of that made more sense to him than me at the time he was the engineer and I was just a mule.

Anyway all I was attempting to do was help the more novice HAMBer understand Joe's concerns a little bit not say long rods bad.

 

I had lunch with John Holmes once ,we did discuss stroke but I won't go into it here!!

 

Well I hope you didn't have hot dogs.

 

Lot of good stuff here, fun to read. Used to be a bottle racer, switched to turbos. Nitrous likes a short rod, less dwell time at TDC. Helps with detonation. Good set of forged pistons, decent heads, and a simple plate. !50 shot will wake it up when needed. Only need to pull 6 degrees of timing, take it out of the distributor advance, leave static alone. A 375hp 400 is magically making 525.

 

Fun thread & thanks Beaner for the mopar deck height lesson, always 2 sides to every thing & I enjoy hearing the how stuff came to be. I once knew this guy, who knew this guy, who knew this guy, that knew this guy, who had a friend that got Smokeys autograph in K.C. Mo at a open house parts show in 1980 sum thing. Flux

 

LOL
Funny my wanderings have meant that I have crossed paths with a lot of folks some way more different than others and some way more important than others. None of them ever made me any more then the nobody that I am. But I have had a good time along the way.

By the way I do like getting others perspectives on things, when someone doesn't agree with me it gives me a chance to rethink what I think I know.

 

sorry, didn't mean to be mean ! you know what i mean ?
and realistically, putting a long rod in there wouldn't be in with the budget part.. probably just cast(not hyperjunk) pistons would be just fine . have an awesome day !!

oh yeah, wonder about the hot gas engine !! that guy did not think inside the box, for sure!!

 

I actually read an article a couple of years back on the engine with the theory behind it. I guess he worked with GM and made his hot gas engine work, and like all things Smokey it worked well. From what the article said it was too pricey for GM and they bailed, to date no one has picked it up and it is a shame. I have thought about doing the research and seeing of I could reproduce it, the research is done so it would just be a matter of finding out what was done and how. No real R&D to complicate things money wise.

he also did a deal with a CanAm ( maybe it was Transam) Chevelle that I would like to do just to screw with people. it was almost as big as a real one. It would be fun to build one and park it in line of 'em to see the reaction it got while people were trying to figure it out.

 

This was the direction I was going in
http://www.hotrod.com/how-to/engine/ccrp-1112-406ci-small-block-chevy/
Read this and the previous build they did to get some parts combos