aluminum rod tall dart honda

[dart2.2]

im going to be putting aluminum rods in place of my eagles that are currently in there. im using the eagle 95 mm stroke and am going to have to do some notching and am wondering if ill run into any water or oil passages. thanks for you help. i also heard dart leaves the deck a little tall and decking is required. is this true?

[kevin@dart]

Actual deck height will be .001” - .005” taller for additional machining requirements.

SEATING THE SLEEVES :
Before honing sleeves or decking block you MUST install a torque plate using a head gasket. This will assure the sleeves are seated in the block. The sleeves should be above the deck .002" when new and .000" - .002" above when used. After block has been decked it should be at 0.000”.


Clearancing for the aluminum rod is a touchy subject. You do have room to clearance however, alumunum rod sizes on the big end can differ quite a bit.

After speaking with an engine builder who uses our block he said he has buildt steel rod combinations at 95mm with little to no clearancing but thinks the aluminum rod might be tough.

He suggested you mock it up to see just how much material would need to be removed. You may actually have to cut into the bottom of the cylinder and the rod may interfer with the windage tray.

If you can come up with a measurement of what you need to remove and where we may be able to tell you if you are going to poke through anywhere.

[dart2.2]

Actual deck height will be .001” - .005” taller for additional machining requirements.

SEATING THE SLEEVES :
Before honing sleeves or decking block you MUST install a torque plate using a head gasket. This will assure the sleeves are seated in the block. The sleeves should be above the deck .002" when new and .000" - .002" above when used. After block has been decked it should be at 0.000”.


Clearancing for the aluminum rod is a touchy subject. You do have room to clearance however, alumunum rod sizes on the big end can differ quite a bit.

After speaking with an engine builder who uses our block he said he has buildt steel rod combinations at 95mm with little to no clearancing but thinks the aluminum rod might be tough.

He suggested you mock it up to see just how much material would need to be removed. You may actually have to cut into the bottom of the cylinder and the rod may interfer with the windage tray.

If you can come up with a measurement of what you need to remove and where we may be able to tell you if you are going to poke through anywhere.

ok thanks for you help. the area im questioning is the oil galley for the piston squirter. is there anything that relays on the oil that would come through here or could it be pluged/welded shut? and i relied on my builder at the tim and he said he didnt use a deckplate to seat the sleeve nor did he have the deck machined. my engine is apart now so im thinking that it needs to be decked as im having head gasket sealing problems.i talked to my machine shop and asked him to keep the big ends on the smaller side and asked if i could get a template or some kind of comparison in size. thanks again.

cole.

[Awesome Bill]

The aluminum rods will not be a problem but will also add nothing to your rotator or help with sealing anything. Your head gasket problem is the deck and your old engine builder. I don't think he would still be my engine builder is he did not torque plate and deck the engine before assembly. He is the reason you have head gasket problems. If you want to pay him to learn on your stuff, that is great news for him, but we don't learn @ your expense.

We toruqe plate overnight then deck then plate hone for 0% leakage with these engines. You don't even need a vacusump system.

[dart2.2]

yeah, he is no longer doing anything for me. this was 3 years ago and i just recently got the car tuned and racing. i want to go with the aluminum rods due to the fact that they are cheaper and turnaround time is faster. id also like to rev the engine higher so im gonna decrease the stroke from 95mm to 89mm. that should give me plenty of clearance inside and still allow room for the alum rods so hopefully i wont havr to clearance anything inside or atleast kepp the notching to a minimum. i guess you get screwed and learn to assemble engines on you own. live and learn. thanks for you help guys.

[Awesome Bill]

Machine shops and engine builders are 2 different things totally. You need an engine builder who is a and has a machine shop with dyno to really get your money and piece of minds worth. Call Keith Groden and tell him Awesome Engines told you to get his rods. He makes the best Honda Aluminum Billet Rod going. He is sharp and won't break the bank. You get what you pay for nothing else.

[dart2.2]

ive allready placed an order with mike at r&rconnectingrods.com. ive also heard good things about groden though.thanks for you help guys and ill keep this site in mind for tech help from you guys. just a quick question. is the compresion height the same meaning as wrist pin height?

[Awesome Bill]

compression height or pin height is the amount of distance you need from the center of the pin to the top of the piston to make your stroke and rod length come out to what ever you need. We generally add .020" for aluminum rods and sometimes a lot more depending on rpm

[dart2.2]

ok thanks. i need to contact je pistons to find out the pin height on my pistons. once i find out that what measurements are needed to figure out what rod length. my deck height,pin height,stroke, and? thanks again. cole

[want-a-be]

ok thanks. i need to contact je pistons to find out the pin height on my pistons. once i find out that what measurements are needed to figure out what rod length. my deck height,pin height,stroke, and? thanks again. cole

You need to know the deck height of you block. Center of the cranks main journals to the deck of the block.

from there Piston pin height, rod length, and half the cranks stroke needs to add up to the deck height of the block. Actually it's usually about .005" to about .050" less then deckheight.

Need an example? lets use a SBC block that usually has a blueprint deckheight of 9 inches. I have a 350 ci crank, which has a stroke of 3.5 inches, and 6" rods. Frm these numbers we can figure out piston pin height.

Take your 9" block height. subtract the 6" rod length. leaves you 3" subtract half the stroke, half of 3.5 in this case, which is 1.75" which leaves you with 1.25 for the piston pin height.

Said a bit differently it is
half the stroke + rod length + piston pin height = deck height of the block.

Remember to factor in a good safe piston to head deck clearance... but this should be able to tailored to your needs with head gaskets.

Hope this wasn't more confusing then it is helpful.

Don

[dart2.2]

yeah im new to all of this and want to learn as much as i can. i know my deck height is 226mm and stroke of 89mm. once i find out what the pin height is there any calculation to give me a correct rod length. i was running the 95mm crank and a 5.967 rod length. ill be reducing the stroke to 89 mm and want to reuse the pistons with a new crank and longer rods. so i wanna make triple sure i get the rod length right. again im new so any help is appreciated.

[want-a-be]

,.....I just gave you the math. Just manipulate it around for any numbers you need. once you get the pin height of your pistons you'll be able figure the rod length. When you get the numbers post them here and someone will help you with them. I'll bet good money that who ever helps there will be someone else checking their math.

You'll need to convert everything to metric.

Don

[dart2.2]

,.....I just gave you the math. Just manipulate it around for any numbers you need. once you get the pin height of your pistons you'll be able figure the rod length. When you get the numbers post them here and someone will help you with them. I'll bet good money that who ever helps there will be someone else checking their math.

You'll need to convert everything to metric.

Don

ok i found out that the pin height is 1.045". the deck heght is 8.897" and the stroke is 3.504". im still confused on how to figure out rod length. math was never good to me. so if i take the deck height if 8.897" and subtract the pin height of 1.045" that gives me a center of the writst pin of 7.852". then divide the stroke by 2 and that comes out to1.752". i then subtracted the half stroke of 1.752" from the center of wrist pin from the top of the block at 7.852 and came up with 6.1, is this correct and being that the rpms are gonna be at 10.5k with the aluminum rod should be .003"-.004" shorter than a steel rod correct.im running a .030" head gasket and when i measured with a straight edge i had the top of the piston at .015". all of that need to be taken into consideration as well right? so a rod length of 6.095" would be right?

[want-a-be]

Hey bud,...let me tell you, my math suck,...but I've developed a good solid understanding of practical math. Which I consider this to be. That being said.....

Your math looks pretty solid. The only problem I see is you were a bit wrong, or misinformed, I think with the how much shorter the aluminum rod should be then the steel rod. In your example you're using .003"-.004". Thats a lil' shy of where it should be. The aluminum rod should be more like .010" to .015 shorter then the steel rod. I'd lean towards the .015"-.020" since your rpm is going to be in the 10.5krpm. Which would put your rod length at about 6.085" to 6.080" in length.

One thing I do have to question though is your piston pin height. Are you sure that your pin height is 1.045". This would mean that your wrist pin is well into your oil ring. Not uncommon by any means. But I wouldn't have used that kind of pin height in a piston is I had a rod stroke ratio like you're going to have. Just asking that you be sure that measurment is correct before you comit to anything.

Why are you wanting to go to the shorter stroke again? What is the older stroke, in inches?

Hope this helps out. Might have someone else check my math also.

Don

[dart2.2]

Hey bud,...let me tell you, my math suck,...but I've developed a good solid understanding of practical math. Which I consider this to be. That being said.....

Your math looks pretty solid. The only problem I see is you were a bit wrong, or misinformed, I think with the how much shorter the aluminum rod should be then the steel rod. In your example you're using .003"-.004". Thats a lil' shy of where it should be. The aluminum rod should be more like .010" to .015 shorter then the steel rod. I'd lean towards the .015"-.020" since your rpm is going to be in the 10.5krpm. Which would put your rod length at about 6.085" to 6.080" in length.

One thing I do have to question though is your piston pin height. Are you sure that your pin height is 1.045". This would mean that your wrist pin is well into your oil ring. Not uncommon by any means. But I wouldn't have used that kind of pin height in a piston is I had a rod stroke ratio like you're going to have. Just asking that you be sure that measurment is correct before you comit to anything.

Why are you wanting to go to the shorter stroke again? What is the older stroke, in inches?

Hope this helps out. Might have someone else check my math also.

Don

the pin height was raised to accomodate the 95mm stroker kit i had in there and was going to reuse the pistons, but i think ill just get new pistons while its out as i dont like the pin going though the oil ring. the new pin height is 1.181. so with the new pin height and the formula you provided i came up with a final rod length of 5.943". on eagles website i put all these numbers into the calculator they have and it gives me .02 deck clearance. and with my .030 head gasket would you recommend having the rod made 5.933" or is the 5.943" ok? thanks again for your help.

[dart2.2]

just wanted to say thanks again to you that chimed in and helped me out in my answer for my rod length. cole

[want-a-be]

No big deal bud...we are more then happy around here to help out when possible. Let us know how this turns out for you.

I'd still stay with the longer stroke if this were my build though. What was the stroke in it again?...in inches that is. What was the reasoning with going with the shorter stroke again?

Bill, who posted on this thread also, would more then likely be more then happy to help out with the machining of this block. You ought to give him a call and check him out.

Don

[Awesome Bill]

Your exactly correct but that would put you right @ the 8.897" deck height and with maybe a .040 head gasket and an aluminum rod, you would loose about .020 more and most likely the piston would contact the head and blow up. So you always have to add .020 more with aluminum rods is very safe. So that would mean you would subtract the .020 from the rod putting the rod @ 6.080 or 6.075 putting you about .020 to .025 in the hole so your piston will not hit your head. So where ever you want your deck height to be always remember to put a little more with aluminum rods. We use a standard of .040 with steel rods and .020 with aluminum rods. HTH

[dart2.2]

ok cool. i spoke to mike at r&rconnecting rods, ill have to open up the email again for the exact length but with the .030 gasket ill have .060" piston to head clearance. mike asssured me that should be plenty of clearance. thanks again for your help. are we ok to post a build thread?

[want-a-be]

are we ok to post a build thread?

I don't see why not...I'd like to see how things progress with your build.

Don

[Awesome Bill]

Yep he is right

[vin2911]

HI i am looking for the above block but what is the different between the 2 block ,which block is better for drag use,do any can adv me with the above block can i used 98mm stroker kit with 86mm piston...pls adv the maxi spec for this block .

[Awesome Bill]

HI i am looking for the above block but what is the different between the 2 block ,which block is better for drag use,do any can adv me with the above block can i used 98mm stroker kit with 86mm piston...pls adv the maxi spec for this block .

just saw a rotary engine run 7.27 at the shakedown, you got some catching up to do for sure!