Pulling Forum - want opinions on motor build

want opinions on motor build

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Forum Name: Pulling Forum
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URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=68138
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Topic: want opinions on motor build

Posted By: CAL(KS)
Subject: want opinions on motor build
Date Posted: 04 Apr 2013 at 9:09pm

this is all for Div 2 and 3 Natpa legal 38 WC

My brother and I decided to go 5 3/8 x 4 1/8 in our motor. 287 cubes i feel is enought to compete but not blow the retirement account.

Reason being, H farmall rods will clear and we shouldnt have to do any block clearencing. I am in the process of locating some H rods. Is there a certain casting # that is preferred? I have been told there are several different rods for H farmall.

I can get new 4 1/8 sleeves for $60 each. Is that a good price?

We would like to be in the 10:1 compresson range to stay with pump gas and not have to buy racing fuel. not any locations nearby. given our bore and stroke with H rod, can you recommend a piston? what compression height piston do we need to be in the 10:1 range. I have summit racing catalog and most pistons are listed by cr but that # will mean nothing in this combination. what wrist pin size do i need to fit H rod?

Who does cranks? murphys said im looking at $1100 for crank work. i dont know of anyone in KS that is closer that i would trust for this kinda work.

What specs should the cam grind be? 175, custom?

also have a Tsx 464 to work over for fueling.

should the mains be line bored? or is that for convenience

wheeew.....im sure there is more but this is what i can think of right now.

thanks

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Me -C,U,UC,WC,WD45,190XT,TL-12,145T,HD6G,HD16,HD20

Dad- WD, D17D, D19D, RT100A, 7020, 7080,7580, 2-8550's, 2-S77, HD15

Replies:

Posted By: DrAllis
Date Posted: 05 Apr 2013 at 6:35pm

I have one nearly identical to what you're proposing. Buy a complete set of new 4 1/8" pistons and sleeves and use Buda rods and grind the crank accordingly to get the compression ratio you want. In my case it was 12 to 1 and the 5 3/8" stroke was perfect for my pistons (which had Power Crater bowls). The piston pins are .990", so my machine shop installed new pin bushings and sized them accordingly so it required heating the rod end to install the pins (like most automotive engines). You could also make piston pin buttons to keep the pin where it belongs. Regardless of the bad reviews Buda rods seem to get on this Forum, I have personally built 12 to 15 short blocks with these rods and NEVER had a problem. The majority of these wound up in the state of Ohio. This conn rod and stroke will require some clearancing of the oil pan rails, if I remember right, but pretty sure the camshaft isn't a problem at 5 3/8" stroke. The camshaft is a problem at 5 3/4". I could be wrong about that, as my engine is now 15 seasons old, and been down the track hundreds of times. Now, there are better custom made rods. Fifteen years ago, there wasn't.

Posted By: WCCLASON
Date Posted: 06 Apr 2013 at 12:28am

Thank you for the Good info Drallis.....Its hard to find good info on this site now a days!.....I will put that in my notes. Thinking about building a bigger motor to pull at sigourney ia. next year.....without dropping a ton of money. I know i need a stroker crank of some size but after that im not sure what size or anytihng i want....There is alot of options and Ideas people have on here but who to listen to is getting crazy. i guess i will have to see what the summer brings....

Posted By: wi50
Date Posted: 14 Apr 2013 at 9:18am

I have the blocks line bored, I feel that it is stronger with a surface ground cap bolted tight and square to the block. But I've done them both ways and I'm sure there's lost of them running makeing much more power that still have a stack of shims under the caps.

Probably won't make any difference, with 3 mains and these cranks whipping and flexing around anyway you're not going to wind the engine up fast enough to bust the mains as long as the bolts get tightned.

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"see what happens when you have no practical experience doing something...... you end up playing with calculators and looking stupid on the internet"

Posted By: mlpankey
Date Posted: 14 Apr 2013 at 9:53am

The connecting rod bushing dr.allis is mentioning is a federal mogal part number fed1619y20. Works great with buda rods and 990 wrist pins.

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people if they don't already know it you can't tell them. quote yogi berra