Building a 327 LS1. Rod choices...
07-21-2005, 01:39 PM
#21
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oh yeah, cool idea! i've had a 327 and a 283 in my chevelle and always wanted to throw the 283 crank in the 327 to get the big bore, high revvin 302 of the old school "trans am circuit" camaros.
07-21-2005, 01:43 PM
#22
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Originally Posted by Rokko
oh yeah, cool idea! i've had a 327 and a 283 in my chevelle and always wanted to throw the 283 crank in the 327 to get the big bore, high revvin 302 of the old school "trans am circuit" camaros.
....
07-21-2005, 05:36 PM
#23
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This is actually the same idea I have been kicking around for a turbo motor, albiet with lower compression. The short stroke/big bore combo has always interested me. Back when I had my LT1 Z, I had intended to build a motor using the crank from the 4.3 LT1 that was used in some of the civilian caprices in the mid-nineties. I'm curious as to how the stock 4.8 crank will like being spun hard, though. Either way, I like your train of thought, and intend to pay close attention to this topic.
07-21-2005, 09:43 PM
#24
I know of a Gen 1 SBC with 4.155" bore and 3.48" Crank which is 377 cid with a solid roller setup making 700 hp @7000 rpm and 596 ft. lbs. torque @5000 rpm. Runs on pump gas and is a carbureted monster, and is a crate-type motor. It has 6.2" rods if I remember correctly.
07-22-2005, 09:25 AM
#28
3:1 rod ratio!?!?!?!? That means I need a 12" long rod for a 4" stroke?!?!
Optimum rod ratio is 1.6:1. For a short stroke motor such as the one you're mentioning, you don't need a 6.3" rod.
Whoever said use the longest rod you can is not a race engine builder.
Optimum rod ratio is 1.6:1. For a short stroke motor such as the one you're mentioning, you don't need a 6.3" rod.
Whoever said use the longest rod you can is not a race engine builder.
07-22-2005, 01:07 PM
#32
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Oh god.....
If you say 327 ppl think short stroke big bore.
Say 329 and they are WTF....
It ends up that way based on available crank throws... Call it a 3.27 since that is the 4800 gen III crank throw.
You run your 5.2" rods and the heavy pistons they will need.. the 4800 comes with about 6.278" rods... I will go longer and run slipper skirt pistons...
I will do the LS1 soon enough... I wont go into the ring lands with a wrist pin because I wont sacrifice piston integrity for a bit more rod.... I will use shorter pistons with a pin just below the ring pack.
Long stroke and short rod in blue. Short stroke and long rod in green.. Same RPM... From DSM engine.. Its 2.1 liter tall deck (2.4block) 88mm 162mm rod vs 100mm 150mm rod (std 2.4).
5,500 RPM Thats right over 2000Gs at TDC with the long stroke short rod.. Yuck look at the stroker across BDC..
Conversly, Leaving the others alone and only changing the rod length variable it influences alot of things. Piston weight, piston skirt thrust, piston gforces (accel decel rates) and piston speeds... The rates across TDC and BDC have more influence on induction than peak or average piston speeds. No where near as extreme a difference as a stroker vs a long rod that is'nt stroked....
If you say 327 ppl think short stroke big bore.
Say 329 and they are WTF....
It ends up that way based on available crank throws... Call it a 3.27 since that is the 4800 gen III crank throw.
You run your 5.2" rods and the heavy pistons they will need.. the 4800 comes with about 6.278" rods... I will go longer and run slipper skirt pistons...
I will do the LS1 soon enough... I wont go into the ring lands with a wrist pin because I wont sacrifice piston integrity for a bit more rod.... I will use shorter pistons with a pin just below the ring pack.
Long stroke and short rod in blue. Short stroke and long rod in green.. Same RPM... From DSM engine.. Its 2.1 liter tall deck (2.4block) 88mm 162mm rod vs 100mm 150mm rod (std 2.4).
5,500 RPM Thats right over 2000Gs at TDC with the long stroke short rod.. Yuck look at the stroker across BDC..
Conversly, Leaving the others alone and only changing the rod length variable it influences alot of things. Piston weight, piston skirt thrust, piston gforces (accel decel rates) and piston speeds... The rates across TDC and BDC have more influence on induction than peak or average piston speeds. No where near as extreme a difference as a stroker vs a long rod that is'nt stroked....
07-22-2005, 01:09 PM
#33
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Originally Posted by oange ss
i dont think the 4.8 crank is a drop in for 5.3 and up motors
I'm in the planning stages of a similiar motor that is going to be a lot lower compresion as it's going to be twin turbo and I'm going the solid roller set up as well for the rpm's. I've got a couple idea's I want to try out a few idea's as well. I've got to finish my truck motor first though before I try to tackle this. it'll be spring before I start it. keep us posted I'll be looking forward to any imformation your willing to share.
07-22-2005, 01:38 PM
#34
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Originally Posted by dogger
I'm in the planning stages of a similiar motor that is going to be a lot lower compresion as it's going to be twin turbo and I'm going the solid roller set up as well for the rpm's. I've got a couple idea's I want to try out a few idea's as well. I've got to finish my truck motor first though before I try to tackle this. it'll be spring before I start it. keep us posted I'll be looking forward to any imformation your willing to share.
. They used good cam specs. Special comp etc.. oops gave away my likely grind comp has some profiles to match a GenIII geometry to a turbo setup like that... Its a 3.25 stroke the 4800 is a 3.27.... close enough.With the A4 out of consideration for a swap since only a GenI/II bellhousing kit exists I am also thinking of droping CR and going TT...
I will go iron block to save money, never mess with sleeves and help keep the wheels closer to the ground.
There is alot of room in RX7 swaps...
It could be a miata too... I'd run a C5 transaxle in the miata.
The stock one if just temporary in the Rx7 since it is good for atleast 10s.
FergFab miata swap.
Here the C5 transaxle will leave the much of the trans hump empty.. Good place for turbos
On an RX7 swap... Twins each sitting btw the headlight panel and the ex mani... More room than you would think.
07-23-2005, 10:49 PM
#35
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they look like a couple nie ride's for dropping that motor into. personally I narrowed my down to one of three. either a second gen s-10 a e36 bimmer or a second gen rx7. as of now I'm leaning towards the s-10 as I have a soft spot for them and I got a few ideas I'd love to try on them with suspension type mods. I'm going with a six speed though.that's one nice turbo build up as well. shame it's a ford but they got a few good idea's there.
07-23-2005, 11:00 PM
#36
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I'm worried about shredding a T-56.... I like manuals...
A good shifter & valvebody will be almost as much fun...
Line lock, transbrake and stall converter launches are sweet and consistent.
A good shifter & valvebody will be almost as much fun...
Line lock, transbrake and stall converter launches are sweet and consistent.
Last edited by V8_DSM_V8again; 07-23-2005 at 11:15 PM.
07-24-2005, 09:17 AM
#37
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I'm not to worried about it. I'm planning on upgrading the tranny to with stand a bite more abuse. even still with it upgrade by my caculation's my hp will be a bite over the threash hold. however torque will be down a bite which I hoping to help save me. finding a decent clutch worries me a little more. I kow there's some decent one's out there but none are rated near what I'm planning. as for automatic's I just don't get allong well with them. I've alsway's mad it a point to take car of them welll however I alway's seem to be getting a tranny failure out of it. so I'll leave the auto out of any big hp plan's I've got unles I realy need to go that way because a t56 won't take the abuse.
