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Discussion Starter · #1 · (Edited)
Well, after going around and around with this thing for the past two years, buying and reselling numerous combinations of parts, my build IS going to happen. So much thanks to all the patient "helpers" here!
I do have one last question.
I want to use perfect fit pushrods but if I use my stock height heads and .030head gaskets which pushrods do I use? what about if I use .040 head gaskets? can I get away with stock length pushrods or am I going to need a different shorter length? If a different length is needed, which length? Seems to me that a -.030 perfect fit would be to short. I am using tw37 cams which have a stock base circle I already have the stock length perfect fits and the cometic .040 head gaskets in hand but would actually like to use the .030's to get my compression exactly where it should be.
Any help and guidance on this issue appreciated.
Build is on for this week, virtually all of the parts are in hand just wanna make sure I use the proper pushrods and I really do not wanna use adjustables.
:dunno: :dunno:
 

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Hello adlerx, if your heads are stock then your stock pushrods will still be ok as there is around .100 thou of movement in the lifter.

It is important to set your valve train geometry correct though and your builder should be able to set your valves to the correct height so that the rocker arm is at the inner side of the valve when closed and rolls across valve tip equally on both sides during full cycle of valve.............................

Getting your squish band set by using a .030" gasket is just as important for producing power as most other mods...........

Dont forget to index your plugs when she goes back together, improves your burn, which improves performance/efficiency.....

All the best, Ozzie
 

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Discussion Starter · #4 ·
Thanks alot guys! I guess I got everything I need sept those .030 cometics. Build will be done this week! FINALLY!! WOOHOO!!
 

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Maybe I missed something but I think your compression will be too low for the TW37 cams to run anywhere near their potential. Ideally it should be a minimum of 9.6 to an ideal 9.8:1. Stock heads that are not decked will not get you there.

Stock pushrods for non-decked heads and .030" gasket will work fine.
 

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Discussion Starter · #6 ·
toddlerp said:
Maybe I missed something but I think your compression will be too low for the TW37 cams to run anywhere near their potential. Ideally it should be a minimum of 9.6 to an ideal 9.8:1. Stock heads that are not decked will not get you there.

Stock pushrods for non-decked heads and .030" gasket will work fine.
Yeah, you missed the part where I mentioned the rest of my build, cuz I didn't! Sorry, my bad! If I use SE Hi Comp Forged and .030 head gasket, I should be at 9.8 or pretty darn close since HD lists them as 9.6 with stock heads and stock head gaskets.
 

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adlerx said:
Well, after going around and around with this thing for the past two years, buying and reselling numerous combinations of parts, my build IS going to happen. So much thanks to all the patient "helpers" here!
I do have one last question.
I want to use perfect fit pushrods but if I use my stock height heads and .030head gaskets which pushrods do I use? what about if I use .040 head gaskets? can I get away with stock length pushrods or am I going to need a different shorter length? If a different length is needed, which length? Seems to me that a -.030 perfect fit would be to short. I am using tw37 cams which have a stock base circle I already have the stock length perfect fits and the cometic .040 head gaskets in hand but would actually like to use the .030's to get my compression exactly where it should be.
Any help and guidance on this issue appreciated.
Build is on for this week, virtually all of the parts are in hand just wanna make sure I use the proper pushrods and I really do not wanna use adjustables.
:dunno: :dunno:

LOL, there is never one last question. :thumbsup:
 

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Discussion Starter · #8 ·
:roflback: :roflback:
vafatboy said:
LOL, there is never one last question. :thumbsup:
You are so right!! I just posed another in my new thread where I actually reveal my build!
 

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Hey adlerx,

In your other post you mentioned maybe taking out the chain drives and swapping to gear driven in the future. With the perfect fits I believe you'll have to pull the heads to do that. With adjustables you won't.

darrell
 

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Discussion Starter · #10 ·
Ironrdr said:
Hey adlerx,

In your other post you mentioned maybe taking out the chain drives and swapping to gear driven in the future. With the perfect fits I believe you'll have to pull the heads to do that. With adjustables you won't.

darrell
thanks Iron. yeah, I am aware, if I decide to put the gears in later, I'll just cut the solid ones and go with adjustables at that time
 

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adlerx said:
thanks Iron. yeah, I am aware, if I decide to put the gears in later, I'll just cut the solid ones and go with adjustables at that time

Gotcha :thumbsup:

darrell
 

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adlerx said:
Yeah, you missed the part where I mentioned the rest of my build, cuz I didn't! Sorry, my bad! If I use SE Hi Comp Forged and .030 head gasket, I should be at 9.8 or pretty darn close since HD lists them as 9.6 with stock heads and stock head gaskets.
Is there a difference in the cylinder head/piston combination compression ratio you are referring to, and the CR porters refer to when they talk about milling the heads and using a specific head gasket to get a desired CR?
 

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Discussion Starter · #13 ·
dcfatboy said:
Is there a difference in the cylinder head/piston combination compression ratio you are referring to, and the CR porters refer to when they talk about milling the heads and using a specific head gasket to get a desired CR?
Well, I guess there's would be alot more accurate since they actually measure and match the combustion chambers and know the exact measurement and conversion formula for calculating the compression ratio. In my case, I am just using claimed published numbers from HD but I assume I'll be in the ballpark plus or minus a tenth or two. Trust me, had I asked the correct questions or even had anywhere near a clue of what I have learned since, I would have had the heads CC'd and milled to an exact CR when I had them worked on and it would have been alot cheaper to do then and I would have stuck with the cast flat tops. Since I didn't do that at the time, it becomes economically advantageous to obtain the proper compression ratio using forged SE's instead of having the heads disassembled and milled and re-assembled locally.
 

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Adlerx,
I hope you didn't take my post as a dig. I was just curious. The SE catalog lists the CR for my combo as 9.4:1, but I know think it should be the same as stock since I have the stock heads and gaskets (~8.9:1).
 

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dcfatboy said:
Adlerx,
I hope you didn't take my post as a dig. I was just curious. The SE catalog lists the CR for my combo as 9.4:1, but I know think it should be the same as stock since I have the stock heads and gaskets (~8.9:1).
The stock heads and gaskets with flat top pistons is 8.9:1 (HD claims). When you go to a Big bore (95") and use stock heads and gaskets along with flat top pistons, the compression is 9.4:1. The reason the compression goes up is because the larger cylinder displacement 95 ci (1550 cc) is compressed into the same 85cc stock combustion chamber as was the 88 ci.

You have the flat tops, 95" and stock heads so according to the Moco, you have 9.4:1. But realistically, you have flat tops and larger than 85 cc chambers and that compounded with the Moco generous CR figures, and probably closer to 9.1:1.

Hope that helps clear some things up for you.
 

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Thanks, Springer. Is there some sort of calculator available to compute ball park CRs?
 

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Discussion Starter · #17 ·
dcfatboy said:
Adlerx,
I hope you didn't take my post as a dig. I was just curious. The SE catalog lists the CR for my combo as 9.4:1, but I know think it should be the same as stock since I have the stock heads and gaskets (~8.9:1).
Not at all Dc I know I didn't give much actual build info.
 

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Thanks ViennaHog.
 
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