Thread: 5" Bore Space Stuff

Tweet

I've been looking into the 5" bore space stuff a bit - I know Brodix and Donovan make 5" B.S. blocks but i can't find any information about stroke clearances/ options or the minimum cylinder bore these blocks come with and what you can bore them out to...? - trying to compute for displacement...

Dart makes an Iron 4.9" B.S. block but i don't know of a head manufacturer that makes a 4.9" B.S. cylinder head... i don't even think dart does - does anyone know?

When going this big, how do the cast aluminum Donovan/ Brodix blocks handle things? they are cast and I keep hearing the cylinder walls move quite a bit

most all of it is custom built .you can get up to 730+cid with the 4840 bore space stuff so the 5.000 and 4.900 is far from cheap oil pump dry sump . cams .cranks.intake is custom as for bore size 4.750 can happen .so cid can be big .dart may not list a 5000 .block but will make a billet 6160 block and thats over 20.000 for just the block most of the 4.900 were short deck gm pro stock did make a iron block that may be the dart 4.900 block now

Thanks for the insight Pat - i've researched your work and I know you are a good machinist & engine builder. Looking forward to working with you in the future.

out of curiosity have you ever built a dart 4.9 B.S. bottom end in the past - if so... what did you use for a 4.9 B.S. head? just seeing if i want to go the Donovan 700 route to maximize the 4.840 B.S. or skip all that and go for the 5.0 B.S. - what do you recommend from your personal experience?
thanks

the dart 4.9 B.S. block seems like a dead end with the exception of 2 heads i've found - sonny leonards 14.5 brodix and some Pro-filer heads - i dont think Dart even makes heads for them - already priced out cranks etc... just trying to decide if i want to stay on the 4.840 side or cross over to the 5.0 side

if you want to go big------go the biggest-----however, you will need to be in an area where $$$$$$$$$$$mean nothing------
what is your goal with this engine? unless you are running it in some class where cubic inches/weight mean nothing??????almost any level of performance where you would benefit from this engine would be around a $3million /year budjet---


And Pat s answer to some of your questions will be the same as mine-we won't divulge any info about another customers engine the same as we won't tell any of your secrets---this is far beyond the CRATE ENGINE world-

were just poor boys working on a budget and i would go with a 5000 or better if looking to go past 730 CID as for the 4.900 all this stuff can just start to be a pain in the ass if used parts takes time to work out if you have parts that fit as all lobe on cam core can be moved and custom cam cores . were you could spend over 3000 just in the cam and roller lifters the start of parts were every part you pick up is 1000.s of dollars were the stock bore space stuff is some what less money on some parts and heads come in every shape and size . i have had some 4.900 bore space stuff but not much i stick mosty with the 4840 bs and done many 632 /638 and one 732