I have done a little research. And what I have found doesnt exactly ring true, compared to my personal experience.
From:
Performance Tuning in Theory and Practice, by A.G.Bell.

Stock Motor - 3,500 fpm (cast crank, stock rods and cast
piston)
Heavy Duty Motor - 4,000 fpm (forged crank, peened rods w/ good
bolts, forged piston)
Drag Racing Motor - 5,000 fpm (forged crank, alum rods, lighweight
pistons, etc.)

Now I have personally built 95mm motors that see over 5500 fpm, for quite some time, and assume that some of the full race motors see around or over 6000 fpm.
(100mm stroke at or above 9000rpm.) So other that good rod bolts, what can be done to make these last? Or do have to tear them down every 50 passes or something? Or is all of this info for v8 guys and does not apply to inline 4's?

 

Big stroke = big headache if you are not prepared for disaster.. 50 passes?? Your lucky to see half that if your making serious power and turning high rpm.

 

i had piston skirt proplems with the 95 stroke thats about it the bearings had about 30 passes on them and still looked good 9500 rpm shifts

 

keep it all light weight and have a good piston design.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MHRacing-310 &raquo;</TD></TR><TR><TD CLASS="quote">Big stroke = big headache if you are not prepared for disaster.. 50 passes?? Your lucky to see half that if your making serious power and turning high rpm. </TD></TR></TABLE>

Thats what I am asking, what can be done to prepare for disaster?
Any insight?

 

I know from directly questioning a builder/tuner that was running a B motor with a REALLY big stroke (bigger than 95, thats all I can say) in a record-setting A/M car (went 9s ) he said he changed the bearing after every event which is probably like ten passes tops, more likely less...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b18pwr &raquo;</TD></TR><TR><TD CLASS="quote">

Thats what I am asking, what can be done to prepare for disaster?
Any insight?
</TD></TR></TABLE>

Just make sure your pockets arent scared.. Or go with a setup that will last longer.. Not much you can do. Its still going to happen either way.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MHRacing-310 &raquo;</TD></TR><TR><TD CLASS="quote">

Just make sure your pockets arent scared.. Or go with a setup that will last longer.. Not much you can do. Its still going to happen either way.</TD></TR></TABLE>

Thats what I am thinking, I will try not to cry when my 100mm time bomb goes boom!

 

http://www.calicocoatings.com

 

Is that 100mm stroke in a stock deck? One of those PS cars was running 101 in a stock deck and it was ready to come apart every 6 passes. They had better luck with 103 and a 3/4 raised deck.

If you want a motor to go 50 passes you better start looking to a 95-97 stroke with a raised deck. There is only so much you can do to help. The maintenance takes a bit of time and money but skipping the maintenance will cost you a grip.

 

The problem with building a large stroke B motor is that the b blocks are very short in comparison to the H and K blocks. To stuff anything more than a 98 stroke in a B block with out a deck plate your giving yourself an absolutely horrible rod angle and a piston too short to stabalize itself in the bore. Large stroke motors arent time bombs, they are just motors with a short life expectancy. They are purpose built, that purpose being to produce as much torque as possible and to propel you down the 1320 as fast as can be allowed by your set up. If you look at it like that and realize that this will only last you, say, 4-10 passes before tear down and maintenance is required than youll be ok. Top fuel, Funnycar and pro stock tear down every run. you never see those guys worried about getting longevity because they know those motors are good for 1 pass at a time. purpose built. Thinking that your going to get a full season from one single motor isnt the best way to go about building a race car IMO. I guess it has to do with who you talk to. I dont believe in building race cars to run on the street. I think you should have one or the other, or, if you cant seperate the 2, prepare yourself to spend a lot of money and time to keep it doing double duty.

NA race cars need big stroke/big bore race motors to compete in todays fields, Big stroke/big bore race motors only live a few passes. Thats it, thats all.

 

we run our 99mm motors to 10,300-10,800(k24 engine). I have 80 dyno passes and 4 events(to the finals every event so at least 5-7 passes per event). It has had the same bearings in the motor and has not been taken apart except to switch heads around. It has pistons over 325 grams and steel connecting rods with 3/8th A-1 bolts. I am confident these motors will last without any issues. It is all in the engine build for longevity. I'm sure people will argue about what I am saying but we have the fastest all motor street car in the country(10.89@124 this weekend at Nopi MIR 2200lbs) and we haven't had an engine failure yet this year if that tells you anything.

 

Pro Stock (nhra and Ihra mountain motors) certainly DO NOT tear down after every run. Pro Stock is high compression and gasoline--they check valve springs every run because of the rpm they turn (10,000+ in 500 inch Nhra and 8500 in 820 inch Ihra). Funny Car (fuel) and Top Fuel do tear downs every run simply because of the ridiculous power they make--8000 + is the current estimation--and with the obscene cylinder pressures parts can and do break almost every run. They run oil pressure upwards of 175 psi, and timing over 65 btdc.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jeremyinlinepro &raquo;</TD></TR><TR><TD CLASS="quote">we run our 99mm motors to 10,300-10,800(k24 engine). I have 80 dyno passes and 4 events(to the finals every event so at least 5-7 passes per event). It has had the same bearings in the motor and has not been taken apart except to switch heads around. It has pistons over 325 grams and steel connecting rods with 3/8th A-1 bolts. I am confident these motors will last without any issues. It is all in the engine build for longevity. I'm sure people will argue about what I am saying but we have the fastest all motor street car in the country(10.89@124 this weekend at Nopi MIR 2200lbs) and we haven't had an engine failure yet this year if that tells you anything.</TD></TR></TABLE>

hey Jeremy what was the most HP you guys made out of a 95mm Bseries NA build? if you dont mind sharing

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jeremyinlinepro &raquo;</TD></TR><TR><TD CLASS="quote">we run our 99mm motors to 10,300-10,800(k24 engine). I have 80 dyno passes and 4 events(to the finals every event so at least 5-7 passes per event). It has had the same bearings in the motor and has not been taken apart except to switch heads around. It has pistons over 325 grams and steel connecting rods with 3/8th A-1 bolts. I am confident these motors will last without any issues. It is all in the engine build for longevity. I'm sure people will argue about what I am saying but we have the fastest all motor street car in the country(10.89@124 this weekend at Nopi MIR 2200lbs) and we haven't had an engine failure yet this year if that tells you anything.</TD></TR></TABLE>