molnar crank and rods machined quality?

anyone who has built an engine using molnar crank and rods, i would like to know how the machining tolerances were as far as where your bearing clearances ended up at? did you use standard bearing and get the clearances you wanted or did you end up tight or loose? thanks

You could ask Tom himself about machining tolerances. His username is MT-Tom
I just ordered a crank from Molnar myself but haven't received it yet.

i need to get some main bearings to see how they fit the aluminum caps as my block is in the shop. im thinking about ordering bearings +1 over size for extra clearance. this may save paying for machine work on crank. i need at least .003" clearance on the mains any how.

I purchased a Molner Crank from Todd at Competition Wedge Engines who was recommended by folks this site. He balanced and measured everything up on the crank. I measured everything on the block and was able to spec the bearings. I did buy a couple of the half increment bearings (I think that is what they are called), just in case. Everything came out perfect. I don't recall all the measurements as I assembled the block last year.

i understand bearing clearance will be tight with std bearings using molnar crank and rods. thanks

I just installed a stroker kit that I ordered from Ray Barton. It had Molnar crank and rods. The specs were good.

Are the caps already fit to the block?

no they are not. i still have to drop off the caps.

Then buy your bearings and drop them off, along with the crank, and have the shop set your clearance .

well, thats been my idea. just trying to possibly save on extra machine work if thats possible.

He can/should set the clearance when he fits the caps, no machining needed on the crank unless there is something wrong with the crank specs ...

ok, sounds good. fixes that issue.

So would you order bearings together with crank/rods (standard size?) or separately?

Not to get off track but I see your from Graz Austria DGS.
I worked for magna there a few times
Never though I see a mopar enthusiast from there.

That's funny, when I was still in college I used to work there over the summer

No. Just ordered all bearings today. Went with king for the cam and rods. They are a h bearing. Clevite p bearing with full groove for mains. Yet to buy crank and rods. Have not made up my mind on the molnar stuff yet. Looking for excellents in machining if that exists.

I'm thinking about mb5116hp bearings for the mains and cr808hpn for the rods (both from king).

My machinist was amazed at the quality!

My 4.25" crank and 7.1" rods get beat on almost daily in my 505.

I just checked all my Molnar rods this weekend. All pin bores were with-in .0001", all rods with bearings installed were +/- .0002" but I did not measure the rods and bearings separately. Clearance depends on what your crank is. Mine would have been .0021-.0022 with a standard 2.2000" journal with a coated Clevite 743HN CL77. I have no idea how thick the coating is as they were done before I received them. Total weights were with-in .9 gram except one 1.4 gram.
Doug

cr808hpn is what i ordere. Fits 2.200 journal. 533hp for the cam if i remember correctly.

Sounds like you got a good one. Read and heard from others that theirs were not as good as yours. I was hoping to use the crank right out of the box. I may take a harder look at scat.

If it were my motor I would get all the parts then start measuring. If you don't know how or don't have the tools to do so than pay someone you does.... I don't care what anyone says, you don't know what your clearances are till you or someone measures you're clearances....
I had to buy 2 sets of bearings to get the clearance I wanted.

absolutely and couldn't agree more. i have the mics and dial bore gauge and will be measuring as i have all the engines i have put together. what would be a good affordable digital dial gauge for my bore gauge? brand name?

If what you have is accurate and have had no issues with your previous builds then I would use what you have.

i would like to replace the analog gauge for a digital one. what brand of gauge would be affordable yet accurate enough to measure bearing clearance?

plan on dropping a lot of coin for a good digital one, I was looking at more than a grand for one that can measure in .0001 increments. Tim

wow. i priced the brand i seen in one of Andys pics in his book. they were $300. im looking for something around $100 if that is possible.

here is a $30 gauge with the same accuracy as the $300 gauges. same accuracy as my analog but i can read it easier as well.
http://www.ebay.com/itm/0-12-7mm-0-5-0-01mm-Digital-Probe-Indicator-Electronic-Dial-Test-Gauge-/221842075927?hash=item33a6d17117:g:YRQAAOSwd0BVvVVD

I prefer an analog gauge, graduated to .0001. That way, I can see it sweep towards zero, and very easily take a reading off the needle, without having to digest a bunch of moving numbers. IMHO, .0001 is essential, .0005 is too vague.

i just may do that. All i have found with that accuracy was $200.

Curious what issues you've heard about Molnar products because all that I've heard has been that their quality is extremely good.

Same here
Post a link

well we have been lead to believe they were near perfect. Doesnt look like it from the few pm's i received from members who have bought molnar cranks. Not bad product just not as good as we have been lead to believe.

Without "outing" the senders of those PMs, can you post the pertinent info contained in them? Thanks - Brad

Its sounds to me you have a 50/50 chance at getting a crank that doesnt need machining. Dont want to spend $800 on a crank and have to take it to a machine shop to make it right. Any where from .0005 difference from one journal to next to having too tight clearance and having to have some taken off. .003 difference in lenght of rods. Some get a perfect crank and some dont. Its probably what i will end up with since i cant afford any thing better to be honest. I had problems like that with eagle and thought i could get away from all the extra machining.

i must have either got luck or muscle motors cleaned it up. my machinest said my was really nice.

I have yet to see any bad comments about Molnar products anywhere that I've searched. How are they accurately measuring rod length at home? How good are their tools? I'll bet that the measuring instruments at the manufacturer are a hell of a lot better than what most people use, including me. To be honest I didn't measure the length before hanging the pistons. If the deck height checks poor I'll investigate the cause. In my experience there is a stack up of correct crank index/stroke, pin location in the piston, and rod length. I've personally never built a motor that measured exact deck on all 8. I think a lot of builds miss import measurements and sweat the stuff that in most cases means nothing. How may measure lifter bores for size and placement, ring side clearance, bore for out of round and taper to the .000X? I'd rather have a few .0001" extra on he bearing or miss the deck height by .003" than have lousy bore or ring groove dimensions. Just my 2 cents.
Doug

I will say that if anyone has a problem they should call and talk to Tom. He's accessible and answered a couple of questions I had on rod side clearance. Very helpful!

We had a minor problem of a misboxed BB Chevy crank in a Mopar box. It was remedied immediately with no hassle!

i agree. Not saying its horrible stuff. Just not as perfect as i read about their products. I will most likely buy molnar crank and rods. You can bet i will report here good or not so good. If i spend $800+ on a crank only having to remachine it I wouldnt be to happy. I can do that with an eagle crank.

The Molnar crank I have measured up pretty decent. Mains and rods had virtually zero taper and were within ~0.0002" across the board. I made the mistake of ordering my Indy Maxx block with 400 mains, so bearing selection is terrible. I ended up going 0.010" under and having the shop turn the crank where I wanted to get the clearances around 0.0033"-0.0035".

which bearings did you go with? not sure what other brand cranks for 400B are offered in the 4.150 stroke with 2.200 rod journals, but i may just go on price alone if i have to have the crank machined anyway. i dont think the main bearings for the B engine are offered in over sizes(thinner) like a +.001 for instance. that would have been nice.

Totally agree. I do a lot of work with shops and teach them measuring. No one uses a digital one.

Ok. Are the shars dial indicator any good? Which is most accurate a .250 dial or a .125 dial both with incerments of .0001?

one will be just as accurate as the other regardless of travel length.

I agree. And I said, I bought some additional bearings in + increments just in case I needed them at assembly. I didn't use them.

I have a Molnar rotating assembly for a 540" hemi out in the shop that we got from Dan at Performance Only. As far as I know, it needed no corrective machining and he spoke very highly of their products.

not much of a selection here for the lo deck, but i'm leaning toward the molnar crank and rods. second choice would be 440source. thanks guys

I wasn't able to find any 400 mains in +/-0.001" sizes. I used the chamfered Clevites that Hughes sells. Had to get a second set(0.010" under) when I couldn't get much more than 0.0025" clearance on the std mains. King makes a 400 main bearing, but they steered me to Clevites when I told them I'd be using a decent amount of nitrous. They said their bearings don't provide enough support for a nitrous application.

To clarify....not ALL King bearings, just the series they offer for a low deck Mopar!

Yeah. King doesnt offer a full groove neither.

Dave What about MB555AM king bearings, those are full groove for the lo decks.

King told me they do not have a performance bearing in a full groove for the 400 block. So that full groove you mentioned must be a stock replacement bearing like the 4094m federal mogul.

I bought Molnar crank and rods for my engine last summer. I was very impressed with them both. All main and rod journal were .0005" under sized (for extra clearace I'm guessing), but they were all the same, zero taper anywhere. Only thing that I had to do to the crank was balance it, and it didn't take much to do that.
The rod bushings were sized correctly out of the box (unlike the previous set (differnt mfg) that I bought that the pin wouldn't go into at all, another trip to the machine shop and more $'s)
If I were going to buy a crank today, my first choice would be Molnar.

Brian

ok. iv got it narrowed down to molnar than 440 source. source has an ultra lite 4.250 lo deck crank if i go that route.