The new engine build thread

[88 rex]

Originally Posted by jadkar

The force of combustion!!!! Yes!! I was thinking the same thing. The weight of the piston can change the force on the rod but it's insignificant compared to the force of the combustion.

Think of it..... what would have a greater effect on the acceleration of your hand in a downward motion???

• the weight of a stick of dynamite
• the force of the stick of dynamite exploding

I know it's a rediculous analogy but it makes senses. The piston weight although different is probably not as significant as it may seem.

I think you are underestimating the advantage of lighter/stronger hardware.

I also don't think the force of the combustion is going to obliterate the rods. I'd think that you'd be more likely to blow a headgasket before essentially bending a rod.

This is all obviously pure speculation because I don't see how you can possibly measure some of these forces. In addition, a lot of it will come down to tune on how much fuel you pump in and how much air and how you control the combustion. I don't think you are going to be applying any more force on these rods than say a highly boosted motor.

And as Njn pointed out, the weak point is usually the rod bolts.

[jadkar]

I agree. I am merely saying that when taking into account the mass of the piston versus the overall force exerted on the rotating assembly I think the mass of the piston is the smallest contributing factor.

[88 rex]

Originally Posted by jadkar

I agree. I am merely saying that when taking into account the mass of the piston versus the overall force exerted on the rotating assembly I think the mass of the piston is the smallest contributing factor.

And that's where we disagree because I think the mass of the pistons is one of the biggest contributing factors in if this assembly is going to hold together. Followed closely by rod bolts and rod strength/weight.

[jadkar]

Originally Posted by 88 rex

And that's where we disagree because I think the mass of the pistons is one of the biggest contributing factors in if this assembly is going to hold together. Followed closely by rod bolts and rod strength/weight.

I think the stroke, rod ratio, planned RPM, and block strength have the most impact.

[charliemopps24]

You guys are crazy. Talking all this wierd engineering jargon. We can argue untill our fingers cramp up on us. In the end, john, you're gonna build your motor how you want. Then i'm gonna spank you with my sohc turbo setup.

[88 rex]

Originally Posted by jadkar

I think the stroke, rod ratio, planned RPM, and block strength have the most impact.

To be honest I think we should all go rotory and not worry about rods, r/s ratios, and piston weight.

[jadkar]

I'm not arguing.

It's called debate.....and this is how everyone learns

[veris]

Originally Posted by njn63

Thing is, one of the main failure points of a lot of long stroke (ls/vtec specifically) motors that are reved too high are the rod bolts. I've seen more than a few ls/vtec's that were reved to 8k on stoke rod bolts, they stretched, and it ended up spinning a bearing. Those see their main stress on the exhaust stroke i'd assume when there is very little force on the top of the piston and all of the force of deceleration is concentrated on those 2 bolts.

That specifically is why i'm thinking about the mass of the piston as being important.

Also, would the actual force of combustion on the rod/pistons change that much with rpm? It's a more frequently applied force, but does the actual magnitude change much... i'm pretty sure it doesn't.

Yes, rod bolts can often be the limiting factor. The stretching can allow valve to piston contact.

I've always ran ARP rod bolts when running large strokes and high rpm. My first crvtec in 2002/03 was a 10.5:1 85mm crv block (stock rods, arp rod bolts, and JE Pistons.) With that I was confident up to about 8200rpm.

As I understand it rod failure happens most at deceleration from high rpm. Two things cause this. 1) the max piston acceleration is on the down stroke 2) the vacuum on the piston is an enormous force going the opposite direction.

Seems ironic that you'd blow the motor as you take your foot out of it, but I guess it is not that uncommon with crazy combinations.

[88 rex]

Originally Posted by jadkar

I'm not arguing.

It's called debate.....and this is how everyone learns

[triniskill]

Originally Posted by 88 rex

To be honest I think we should all go rotory and not worry about rods, r/s ratios, and piston weight.

yea u can go rotary...and your car will be down a lot more then you want..

[jadkar]

So I finally have some updates, although no photos because I'm lazy

I got my head back from the shop and I still can't thank Transparent enough!! The head looks insane (as it should, it brand new). The shop completely cleaned it and also cleaned the slightly used Manley valve train stuff I got from Jeff. They gave me a wicked 3 angle valve job and slightly ported the ITR head a little more. Believe it or not but they actually had to take .006 off the distributor side because it was a bit high. Right now the head looks amazing and I just finished mounting the rocker arms back on.

The block is down in Asbury Park, NJ with Z10 performance getting sleeved, bored and honed. She'll be done by the end of the week. I already received my 89mm crank also from Transparent and that with the 86mm bore will get me 2086cc or just about 2.1 liters.

The block will sit at Z10 for a little bit because they want my pistons at their shop. This way they can precisely measure them for a perfect hone.

The pistons and crower rods will be coming from Endyn and are way more expensive then I anticipated

My blower has yet to be bought and I'm a little on the fence as far as porting it. I have tons of people on H-T that swear by the process but then I have Jeff Evans and John @ LHT that aren't too fond of the idea. I may leave it unported and see how she dyno's.

Lastly, I'm upgrading my heat exchanger upfront to a 03/04 Mustang Cobra unit. They're much bigger and should drop my IATs a little more.

The big issue my build is going to face right now is CFM of the blower. I am completely running the Eaton M62 to it's limits and the engine has a good chance of falling on it's face after 8K RPM because of this. The problem is the blower is just not going to be able to keep up with the air flow requirements of the large displacement and the high reving of a Honda engine. It's simply going to suffocate the engine. The only option is to keep over-spinning the blower, but that could be disastrous. Imagine the blower blowing apart and throwing stuff into my engine....AGAIN!! So to combat this issue I may have to back my boost goal down to 8psi. There's still a lot of math left to do but this blower is gonna be cranking!! somewhere around 17500RPM!! very unstable. This is why only 2 people on H-T have hit 300 whp. The blower just can't support anymore. My goal is 310 but it's very optimistic, without air the engine's hp curve will just flatten out.

Regardless this summer should be fun. I did some comparisons with Veris's SC'd DelSol and found that maybe, just maybe if I'm lucky I can get to the low 12s. His Delsol runs 12.49 with 279whp and a 300lbs heavier race weight. Obviously he runs slicks and tires seems to be RIOs biggest issue. With that said I'm thinking 300whp, 300 lbs lighter than a DelSol and slicks I should be in the low 12s. I'm very excited!! Check out Veris's DelSol

Veris 12.49 run - Google Video

[Transparent]

awesome man. glad to hear that things are coming together for you.

did you find a buyer for your itr crank? or are you gonna keep it. I remember you telling me that you had a lot of people interested when you were trying to find an ls crank

[88 rex]

Let me start off with I'm jealous


Second, what pistons did you get? Will the tops be coated?

Third, will porting the blower actually help that much? Sounds like you're going to have the blower working over time.

Fourth, ........... turbo still an option?

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.
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Fifth, drop A/C and doing something completely unique.....Rotrex blower


Can't wait to see the finished project!!

[njn63]

do you by any chance know what his 60' was on that pass?

Good to hear everything coming together. Has anyone hooked up a M90 or larger blower on a Honda yet? I know they rotate backwards but there has always been talk about someone doing it.

[jadkar]

Originally Posted by 88 rex

Let me start off with I'm jealous


Second, what pistons did you get? Will the tops be coated?

Third, will porting the blower actually help that much? Sounds like you're going to have the blower working over time.

Fourth, ........... turbo still an option?

.
.
.
.
Fifth, drop A/C and doing something completely unique.....Rotrex blower


Can't wait to see the finished project!!

Pistons are Endyn Rollerwaves, I'm not sure if I'm gonna coat them yet. Do you think it's really gonna help me??

As far as the blower porting helping me.... that's what I don't know. I haven't seen any real "data", nobody has before and after results. They just have "talk". Jeff and John don't like the thought of taking a perfectly good blower and porting it.

Turbo is no option.

Rotrex blower nah, but this is coming out next year from Eaton and suuposidly it will be a direct replacment for many models including M62. The wicked new TVS blower extremly efficeint and on a 2.0liter capable of about 18psi!!!




THE TVS SUPERCHARGER

[jadkar]

Originally Posted by njn63

do you by any chance know what his 60' was on that pass?

Good to hear everything coming together. Has anyone hooked up a M90 or larger blower on a Honda yet? I know they rotate backwards but there has always been talk about someone doing it.

John at LHT spent a lot of money modifing a M90 (NSX blower) to a CR-VTEC engine he built. It was the biggest waste of money! The M90 requires too much torque to spin it and he couldn't keep the belts from shreading. His best run only netted him 255whp

There's a guy on H-T who was trying to do this as well, but the dude he gave his blower to for modifiactions up and disappeared!! So he lost his blower!!


Veris's stats on that run.....

Slicks: 12.496 @ 108.66 mph 60ft: 1.843 (MT 24.5x8x15)
Air Density: 3300ft
Track Altitude: 1600ft
Race Weight: ~2670 (with driver) - passenger seat & sub box removed

[jadkar]

Originally Posted by Transparent

awesome man. glad to hear that things are coming together for you.

did you find a buyer for your itr crank? or are you gonna keep it. I remember you telling me that you had a lot of people interested when you were trying to find an ls crank

I still have all my stuff sitting in the garage. I really haven't been very proactive in trying to get rid of it. I had two guys from H-T that low balled me on it. I'm in no rush though.

[sloganish]

well damnit im very happy to see you staying true to the SC, just cant stop thinking of how much power there is to be had in the form of a snail....:/ it is a road race car thoug...:b

[88 rex]

Originally Posted by jadkar

Pistons are Endyn Rollerwaves, I'm not sure if I'm gonna coat them yet. Do you think it's really gonna help me??

I don't think you'd need to coat the tops. The rollerwaves have all the sharp edges grinded down to help eliminate hot spots. Coating the tops does the same thing. I think T-bone on H-T knows quite a bit about it though if you've got questions. He does the coating.

[triniskill]

Sounds good you got the build coming together soon..
as for he blower..i wouldnt port it..it would be a waste of a blower to do that to it.
just wait and check out that new tvs blower..looks pretty interesting

good luck on everything..