3.700" Big Bore engine...Have ??'s

[Venom_Nitrous]

I posted this accidentally in talk and didn't really get a difinative answer. So here we go again:
Ok, here's the deal. I was going to get a MMR or X2C short block, but Tim and Modularpowerhouse said they have a tendency to spin berings and are not the best choice. I kinda fell back asswards into about an extra $1300 so I am thinking of going big bore. I would get the Aluminum Mountain block:
http://www.karkraft.com/bare_blocks.htm second one down

and having VT do a Dry sleeve upgrade to it for $1195, or I could get the whole kit with sleeves, rods, and flat top pistons (no crank) for $1999 from www.seanhylandmotorsports.com. My question #1 is can any shop put the sleeves in or does it have to be one that can do the MID design? Would my best bet be to go with the Mountain block (strongest aluminum block made) and have VT do the engine or can I have a shop around here do it and buy the SHM kit? I can get the rest of the kit (crank, rods, pistons) from SHM without the sleeves for $1599.
So: about
$900 block
$1599 big bore internals
$1200 sleeves
So, it would be about $3800 for the whole engine. My second question is, I know that strokers have gotten a bad wrap on here, but I can go for a big bore + stroker (5.2) for only $500 more. Should I get this as well. I will be running nitrous and high compression in it if that helps. No plans for FI. What kind of hp would I see from this with the supporting mods listed below (N/A). I think:
big bore: 310?
+ stroker 320?

I have 262 now. Maybe next winter I will get good heads/cams for on top too.


Mods if you could move this tech that would be cool. Thank you and thank you to those who answer.

 

[hotmustang331]

Well these guys on here are all for big bore but in reality CID is CID. The longer your stroke the more lowend torque you have, but also the more topend pull/torque you have (think LS1, how they pull up top). However the car with a stroker wont get the rpms up as fast as a big bore. Basically you MAY get a better ET with the big bore but I almost guarantee that you would get a better trap with the stroker. To me its not worth the extra cash and hassle of getting a big bore for just a HP or 2 (MAYBE)(not torque) over a stroker, if your going to do anything get the stroker. Alot of people want 5K for a big bore its funny. And I take it the rods and stuff wont be forged as I cant imagine SHM actually having a good price on something, those guys are expencive.JMO BTW. I am gonna get a 302 stroker. MAYBE 310 CID stroker. HP wise I would expect around 290RWHP with stock head/cams and a 10.1-1 CR. Heads/cams should bump you closer to 330RWHP maybe 340RWHP.Just a guess though.

 

[Slider]

The benifit of the big bore (over the stroker) is that it helps unshroud the valves some. This promotes better airflow in addition to the increased displacment.

Go over to the modular depot forums, you will get a lot better response there (http://forums.modulardepot.com/).

Well these guys on here are all for big bore but in reality CID is CID. The longer your stroke the more lowend torque you have, but also the more topend pull/torque you have (think LS1, how they pull up top). However the car with a stroker wont get the rpms up as fast as a big bore. Basically you MAY get a better ET with the big bore but I almost guarantee that you would get a better trap with the stroker. To me its not worth the extra cash and hassle of getting a big bore for just a HP or 2 (MAYBE)(not torque) over a stroker, if your going to do anything get the stroker. Alot of people want 5K for a big bore its funny. And I take it the rods and stuff wont be forged as I cant imagine SHM actually having a good price on something, those guys are expencive.JMO BTW. I am gonna get a 302 stroker. MAYBE 310 CID stroker. HP wise I would expect around 290RWHP with stock head/cams and a 10.1-1 CR. Heads/cams should bump you closer to 330RWHP maybe 340RWHP.Just a guess though.

 

[hotmustang331]

Ok, but like I said a few HP LOL. Wasnt sure why it gave more HP but know I know, thanks for the info.

 

[Slider]

Ok, but like I said a few HP LOL. Wasnt sure why it gave more HP but know I know, thanks for the info.

A lot of guys also do not like running a stroker because a longer stroke increases the acceleration and velocity of the piston rod for a given rpm. This is good for lower rpm power, but is not desirable for higher rpm applications, which most racers are looking for. A big bore keeps the same rod acceleration and speed at a given rpm, but you get the benifit of increased displacment.

 

[Venom_Nitrous]

Keep i nmind money is not a huge object. I would love to rev high. Is 8000 reachable of is 7500 about the limit if I get a precision balance and use stock stroke with 3.700" bore?

 

[Slider]

Check out the modular depot forums. They talk about big bore and stroker stuff over there all the time.

link

link

link

 

[hotmustang331]

Hmm true about the rpms, knew that, and yes generally Big block cars run lower RPM, BUT they make the most power and run better times as do 347 stroker motors vs 302s... aslo Big blocks have a HUGE stroke difference over SB fords (66 revs to 7500 RPMS...AND its 331 CID W/ 0 lowend torque) .See your rev range capability is based more on your intake/head/cams WAY more than stroke. 500 CID BBs can rev to 10K, a little stroke increase killing revs is pretty much BS. Like I said that has more to do with airflow and cam profile. With the 4.6 were are not talking going from 281 CID to 408 LOL. Its not a huge difference.I hold my position that BB is a waste of $$$$. But he if you have the cash get the BB stroker. I wouldnt complain about that at all. Heck I wouldnt complain about having either, but for the extra $$ its not high on my list.

 

[hotmustang331]

Just read some of those links...think this backs up what I just said....."You are correct in that a longer stroke isn't going to rev as high (safely) as a shorter stroke. The piston speed on the longer stroke is much higher. But we are talking about the difference of.15 inches in this case which won't make much difference to a street motor. It is not like the difference between a 5.0 3 inch stroke and a 454 stroked Windsor. The big concern here is boost. There is much meat left in a big bore and to throw a KB or Vortec at it with any boost is asking for trouble. If you want to do that you should be lookin at a big bore with Darton sleeves. Serious money just for the prepared block. (I want one bad) "

I wouldnt worry about loosing RPMs with the stroker. Just get what you want...BB would be lighter though.

 

[Mike97gt]

Well these guys on here are all for big bore but in reality CID is CID. The longer your stroke the more lowend torque you have, but also the more topend pull/torque you have (think LS1, how they pull up top). However the car with a stroker wont get the rpms up as fast as a big bore. Basically you MAY get a better ET with the big bore but I almost guarantee that you would get a better trap with the stroker. To me its not worth the extra cash and hassle of getting a big bore for just a HP or 2 (MAYBE)(not torque) over a stroker, if your going to do anything get the stroker. Alot of people want 5K for a big bore its funny. And I take it the rods and stuff wont be forged as I cant imagine SHM actually having a good price on something, those guys are expencive.JMO BTW. I am gonna get a 302 stroker. MAYBE 310 CID stroker. HP wise I would expect around 290RWHP with stock head/cams and a 10.1-1 CR. Heads/cams should bump you closer to 330RWHP maybe 340RWHP.Just a guess though.

i am one of the guys on here thats anti-stroker on a 4.6l well really it's for one reason only. the bore/stroke ratio on this motor is piss poor too begine with. and increasing the stroke will not gain much for the money spent.

where increasing the bore will increase CID plus unshroud the valves on this motor. the valves are tiny too begin with they need the help

 

[TGJ]

i am one of the guys on here thats anti-stroker on a 4.6l well really it's for one reason only. the bore/stroke ratio on this motor is piss poor too begine with. and increasing the stroke will not gain much for the money spent.

where increasing the bore will increase CID plus unshroud the valves on this motor. the valves are tiny too begin with they need the help

I agree, not only that, unfortunately, I can not find the article. However a 5.0L BB was compared to a stock 4.6 and 5.0L Stroker. They all used the same heads, cams, intakes, etc. The Stroker lost lots of HP compared to the stock 4.6 while the BB made significant power compared to the stock 4.6L. 5.0L BB > Stock 4.6L > 5.0L Stroker when using the same hardware. A BB will stand upto boost as well, I suggest you read all 3 links posted above and this one!

 

[Venom_Nitrous]

Well, I did it. I ordered the Mountain block from karkraft and will send it to VT this summer fro sleeeves. I have to still decide on the stroker and compression. What is cooler? Spend another $4000-5000 on a blower for a mostly track car (can't go that fast on roads anyway), or pay another $200 for new jets for the noszle and bump it to a 250 shot. What would be better for nitrous: stroker or stock length? I would guess stroker. I I stuck with the Nitrous I would go ahead right away and get P&P heads and cams. With stage 2 cams and 10.5:1 compression and stage 2.5 heads and stroker could I see these numbers?

350 rwhp N/A
and
600 rwhp w/ nitrous