400 based 512ci cranks and kits

where is a good place to look into them, I have been searching for a 4.250 crank/rods/pistons for the lo deck block and the only thing I have come up with is 440 source,which I have nothing against, but I want some different options for suppliers, seems like everyone has 4.150 cranks but it stops there, eagle, scat K1, compstar etc all have the 4.150 but nothing bigger,,what am I missing?

Molnar has them.

Ohio Crank also has them but it isn't a shelf item. SCAT will turn down a 440 crank to make it a 383 crank, not sure what they charge for that. Molnar is probably the easiest way to go.

440 source has the .4.25, 4.375, and 4.50 as well.. Are you stating no one else has anything in stock other then 4.15 right now?

Should be a simple kit to build yourself. 4.25 crank from Molnar, a set of 6.535 rods from most anyone and a set of 1.32 CH pistons from most anyone. Only real issue is that you need to figure out what dish/dome you need to make the compression ratio that you want. Not everyone sells a big enough dish to keep the the CR down for a pump gas motor. If it is a race motor then it is a little easier.

Molnar will be in my next build if the first and second ever get off of the ground.

$850 for the cranks, $550 for the rods and $750 for Diamond pistons with rings is pretty competitive to the 440 Source stuff.

not as a seperate crank or a kit, as far as 440 source I am not too sure about their pistons, not a brand name as far as I know, thought they used to sell Ross, and I definately don't like their H beam rod's, have seen too many loose the bushing in the small end, looks way to thin and fragile to me and they just mash and desinegrate, I would conside their crank as long as nothing else is special to their product line, I do like the fact that their rod's are wider on the big end and the assembly has way less rod side clearance that a standard chevy rod on a mopar crank which seems to me would sling a LOT of oil and create a bigger windage problem,,,Thanks Andy I checked out Molnar and they have a crank listed.

Muscle motors lists a kit.

It's a race effort, guess I need to look outside the box, I kept looking in the Mopar listings and should of been looking in the brand X listings for the rods, LOL

I would just go with Molnar. I've heard nothing but good things about them, and I'm sure most know Tom used to be with K1 before he went out on his own. I would go with Wiseco or Diamond for pistons. That's my plan unless I can score an aftermarket block in which case I'd like to build a 540" or larger.

What head are you using and what compression ratio do you want? If you tell me those two items then I can probably tell you what the best piston to use is.

I have a list of stroker pistons in the tech archives in the big block section.

Yep, they are building one for a little street car project sitting in my shop as we speak, should arrive in the next week or two and fit nicely under the Porter prepped eddys

plan is to use the new Trick Flow heads,,when ever they are available, won't be doing anything untill sometime next year, maybe by then they will have their new max wedge head out.also the chamber cc on the TF heads are 78cc

A flat top piston with -5cc piston relief will give you 12:1 compression with the TF heads. That would make a nice race gas engine. Easy 700 hp combo with the TF heads and a healthy roller cam.

Diamond, ICON, Ross, Mahle and SRP all have a shelf piston that would work if you go with the 4.375 bore size.

Tons of people make a Chevy 6.535 long rod so just pick whatever works for your budget.

You have a PM on this

Your missing about 14 cubic inches - stay with the 4.15 kits easiest way to go

The Eagle kit B21103030 is balanced and uses the Mahle pistons and a 6.760 rod with the 2.2 pin

Price at Summit is $2200 with a 10% coupon = $1980

thanks for the info guy's you have been a great help.

My Dad just got some Molnar rods and Race Tec pistons through Molnar, nice pieces and the customer service seemed pretty good.

I just put Mahle's in my mill. Very nice pistons. That's basically the kit I have with the Eagle rods and crank.

I have two 4.5 cranks from 440source. There both nice.

440Source's $2250 price includes balancing and shipping.
The pistons started out as Ross, then were ICON, and they don't say now except they're CNC produced in America out of American forgings. If you don't like the rods then move on.

Re: small end bushing problems - Is it possible that the pin is flexing too much?

I'd say whatever you do, start out with the idea of using 2.20 rod journals and 0.990 pins as these unlock the door for a wider variety of parts.

Been through this a hundred times, but the oil flow through the rod bearing is metered by the clearance between bearing and journal. The side clearance is so much bigger that it makes no difference on oil flow out of the bearing. Many circle track racers run those clearances extra big, keeping the rod in place by the piston pin boss. Look up "piston guided rods". There is obviously horsepower in eliminating that friction.

R.

Thanks for the info, as far as the rod bushing's that I have seen both failed and non failed the bushing thickness appears to be to thin, wall thickness wise seems un supportive,could be material could be thickness not sure, i suppose you could remove them and replace them with a known top quality bushing and all would be good, just food for thought.

The trick is to use the Chevy rods. They are made in much higher volume so you can get higher quality rods for less money. For a 512 you should be able to use a very common 6.535 rod. Another great benefit of using the Chevy rod is that then you can use Chevy rod bearings. There are a ton of those bearings available including different widths, coatings, etc.

If it was me I'd probably go with the Molnar crank, some SCAT H beam rods and the SRP pistons. That combo should fall together and make really nice power with the TF heads.

Well Andy you are real close to what my list is, only diff is Eagle rod's and Ross pistons, I will look at the Scats and srp's

The SRP 213453 pistons are $560 at Summit while the ICON 823 pistons are $627 and the Ross 99495 pistons are $690. I think these are apples to apples prices but you have to double check to be sure. Diamond also has a shelf piston but they sell direct so you have to call them for pricing.

I'm sure that Molnar also has a 6.535 rod and his prices are usually really good. The SCAT rods are $485 at Summit with the standard bolts which should be fine for your application. You can put together a total stroker kit for about $1900 from Summit. If your engine builder has a wholesale account with Summit then they get an additional discount.

once again Andy you (and others) have provided excellent info and you just verified my parts selsctions, Thank you very much,,,now its time to start building the savings account back up.

I think "Hell" has frozen over --------

I thought it was getting cold around here, guess it's time to step off into the deep end and either sink or swim.lol

Go Big (block) or go home.........and just as we are getting ready to go HEMI..........hell is icing up pretty quick.

I'm still trying to figure out how come there are no oil leaks with all them holes in the valve covers

And why did they hide the spark plugs in them holes

Funny looking engine - do they have a video pictorial I can watch to see how to change the spark plugs

Whats this Hemi thing anyway - could be a pretty Hefty thing

Ross pistons, GRP Chevy style rods, and crank of your choice, light and strong.