Dart B18/B20 replica blocks
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Well I’m in the mist of a new engine project for the CR-X, ever time I do this it gets more and more elaborate…. So this time I’m thinking this Dart B20+ block may be a good route considering it allows for the R/S ratio of a B16 that I feel I need. So I guess I start yet another engine build project… B20/VTEC here I come
IMO there are two primary reasons to consider the Dart block:
1) You want an NA B series motor with as much displacement as possible and as high a r/s ratio as possible (without resorting to deck plates).
2) You want to build a large high boost turbo B series and don't already have any sort of real block prep or even an engine block.
in either case it makes much more sense if you won't be using many factory parts, as the more you have to buy the more likely you should consider buying an aftermarket block to go along with the new internals.
1) You want an NA B series motor with as much displacement as possible and as high a r/s ratio as possible (without resorting to deck plates).
2) You want to build a large high boost turbo B series and don't already have any sort of real block prep or even an engine block.
in either case it makes much more sense if you won't be using many factory parts, as the more you have to buy the more likely you should consider buying an aftermarket block to go along with the new internals.
OK guys heres a qiuck run down, not the details but the basics.
Head running Toda
P&P
bolt-ons
Blah blah blah
Ok block
12:1CR
Weisco pistons
bore out to 84.5mm
eagle rods
golden eagle "godzilla" sleeves
gsr crank
My plan is to pick up a 94 gsr and build a weekend warrior car, that i could drive to the track. I wont drive it everyday, just the weekends and maybe a day or two during the weeks of the summer, once winter comes i would retire it to its enclosed home(aka the garage).
I was planning on just using the existing motor, to do all my block work. Should i envest in the dart block or not? let me know what you think and the reasons for your thoughts.
thanks guys.
Head running Toda
P&P
bolt-ons
Blah blah blah
Ok block
12:1CR
Weisco pistons
bore out to 84.5mm
eagle rods
golden eagle "godzilla" sleeves
gsr crank
My plan is to pick up a 94 gsr and build a weekend warrior car, that i could drive to the track. I wont drive it everyday, just the weekends and maybe a day or two during the weeks of the summer, once winter comes i would retire it to its enclosed home(aka the garage).
I was planning on just using the existing motor, to do all my block work. Should i envest in the dart block or not? let me know what you think and the reasons for your thoughts.
thanks guys.
You will not have a 1:75 rod ratio with a b18B crank(b20) and the dart block........
A stock block have a deck height of 211.5mm , the B20+ block have a 226 mm deck height, so the B20+ block have 14.5 mm over the stock block!
ESP (eagle rod) make a special rod to use with the B20(B18B) crank and the B20+ block! The rod is 5.531'' long and a B18B(B20) crank is 3.504'' (89mm) So 5.531/3.504=1.578
B20+ block with 89mm crank = 1.578 rod ratio!
A stock block have a deck height of 211.5mm , the B20+ block have a 226 mm deck height, so the B20+ block have 14.5 mm over the stock block!
ESP (eagle rod) make a special rod to use with the B20(B18B) crank and the B20+ block! The rod is 5.531'' long and a B18B(B20) crank is 3.504'' (89mm) So 5.531/3.504=1.578
B20+ block with 89mm crank = 1.578 rod ratio!
Well...there seems to be a bit of conflicting viewpoints on this subject, as there should be because, I find myself swapping sided of this argument all the time. Although a few weeks ago I had an epiphany...
We were changing the head gasket on my friends car and suddenly I stared at it and said to myself..."how does a block guard inhibit coolant flow?" If you look at a Honda head gasket the passages for the coolant flow from the block to the head are nothing more than a few holes spaced evenly around the circumference of the cylinder.
The only thing I can think of as far as overheating goes would be that if you used a block guard, and the holes in the block guard didnt match up completely with those of the head gasket, this would seriously impede coolant flow and probably cause overheating....makes sense. However, if a block guard is designed to match these holes perfectly then there should be no reason that this would affect the cooling properties of the block simply due to the fact that even though the block is open deck, the coolant still must pass through small holes in the head gasket to get to the head, so in essence your coolant wouldn't know whether you were running an open or closed deck anyway.
Just something I noticed...is this even worth mentioning, or am I just stating common sense and I'm just too dumb to know any better??:laff:
We were changing the head gasket on my friends car and suddenly I stared at it and said to myself..."how does a block guard inhibit coolant flow?" If you look at a Honda head gasket the passages for the coolant flow from the block to the head are nothing more than a few holes spaced evenly around the circumference of the cylinder.
The only thing I can think of as far as overheating goes would be that if you used a block guard, and the holes in the block guard didnt match up completely with those of the head gasket, this would seriously impede coolant flow and probably cause overheating....makes sense. However, if a block guard is designed to match these holes perfectly then there should be no reason that this would affect the cooling properties of the block simply due to the fact that even though the block is open deck, the coolant still must pass through small holes in the head gasket to get to the head, so in essence your coolant wouldn't know whether you were running an open or closed deck anyway.
Just something I noticed...is this even worth mentioning, or am I just stating common sense and I'm just too dumb to know any better??:laff:
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sorry to ask a dumb question but what are the bore stroke numbers for a b18 as well as a b20? B20BbenN u made it sound as though the b18 and b20 use the same crank and although i might be wrong (wouldn't be the first time) i thought the the b20 was essentially a stroked b18 with the same bore.
any help would be appreciated. peace
any help would be appreciated. peace
That math doesn't work out. The deck is 14.5mm taller than a standard B20, which uses a 137mm (5.394") long rod. With an 89mm stroke, that nets you a 1.54:1 r/s ratio.B20BbenN said:
If you expect the piston to be in the same location of the bore with a 14.5mm taller deck height, you need to also make the rod 14.5mm longer. 151.5mm (5.965") long rods with an 89mm stroke nets you a 1.70:1 r/s ratio. Now I earlier stated a 1.74:1 ratio (I had forgotten when I did the math last it was for an 87.2mm B18C crank), but it's clearly larger than a 1.58:1.
ive been going over a-lot if information for my next engine build, and ive decided to go with the dartb20 however I was unaware of the improved r/s ratio thanks for pointing that out I was focusing on the higher endurance due to the closed block and build materials, the final concept is to remount my pro-charger supercharger to a built b20***** <using the block in this string> with a decent compression ratio and a prepaired b18c5head <with both intake and exhaust ports bored out slightly to accomidate higher displacement over a b18> So far youve made plenty of excellent comments, does anyone know if the bolt patterns on the dart blocks are for the ***** heads or the non ***** b18 and b20? Just a thought as I allready have my ls head and could pick up the new block and use it sooner if the head bolts are right
imo, id stay away from this block untill its proven.. i dont know of anyone that is running it yet. i dont like the fact that the main caps are steel and the block is aluminum. these to metals have different rates of expansion and such. i dunno, just dosnt sound like a good idea to me
i was gonna post a new thread about engine blocks till i seen this one. any other places like dart online that has b series engine blocks????????????
sometime in my lifetime im going to build a super clean all motor or MAYBE turbo for my crx and was wondering.
sometime in my lifetime im going to build a super clean all motor or MAYBE turbo for my crx and was wondering.
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