jerryd87

iTrader: (4)

hate to break it to you but you should talk to nelson directly instead of quoting a magazine, i have and he runs much looser clearances then that add another .001 and thats his minimum clearances he runs on his high power twin turbo 427's. also shouldnt quote a build that didnt even last a full race season(that 388), i personally watched ashley forces team spec bearings mains to .0075 in 07 at night under fire right before loading the engine up with 75 weight, are you trying to say they have a **** machine shop?
not to mention the HUNDREDS of racers and builders ive worked with including bushur racing, switzer performance(i lived in oberlin) as well as sever other shops including paul cole engines in oberlin(retired) who had a several month waiting list for his meth motors, motorheads in legrange, and wallace and dewitt engines all of which built 700-2000 hp motors for dragway 42, norwalk dragway(now summit motorsports parkway), lorain county speed way and even further out for circle and drag racing with a few gt engines thrown in. not a single one of them used tight clearances and not a single one of them had issues with spun bearings coming back.

not only that but despite what you say about nascar they use 0w50 for qualifying and 15w50 for races and actually run around .0030-.0035 right where they should be for the power they make a friend of the familys owned one of the lesser teams before selling the team in 08.

the final nail in the coffin in the number of spun bearings here from "oil starvation" that come out of shops attempting to use tight clearances one of which is GTM despite having a state of the art engine machine center. yet none of the people with loose clearances and heavy weight oil have issues, ive said it since i joined and am repeatedly proven right every time someone trys tight clearances. hell i have more miles on a single engine then cass had in 4.

sorry you might make a ok amount of power for being super charged and come up with a solution to help with belt slip which is awesome but your running a stock block still and out of your league when it comes to engines, ive built way too many of them and i didnt just come up with some wild theory on my own and somehow it worked out.

jerryd87

iTrader: (4)

i will say the only people who i have seen try tight clearances where early 2000's pro stock cars trying to pick up a few extra hp with light weight oils, they tried it for a couple years and went back to heavy oils after the bearings looks like funny car bearings after a single pass and they saw significantly more engine failures on the track as a result.

it was amusing for me though, it usually was followed by pieces of the engine flying out of the hood after the engine locked up and some pistons kept trying to go.

OldManZ350

iTrader: (23)

You are talking about a motor that is an 8000HP Plus 500ci Big Block with a Dry Sump, And Runs for less than 4.00 seconds max under WOT, has huge Journals, and is torn down for inspection every run…….

Lets just Keep it to Vq35's then…….

OldManZ350

iTrader: (23)

Thanks for the Compliment! I've been around the Block a few times myself, but I'm not here to boast. I have a Fairly Heavy backround in Automotive Engineering as well.

So, instead of saying Loose or Tight, can you please Post up Your Numbers for Mains and Rods +/- .0002 in Vq35 Motors, for Street/Strip FI and Full Race FI.

Thanks
TimRod

jerryd87

iTrader: (4)

i think you would be suprised the big ends are big, but not much bigger then the vq, depending who is building it only about .25-35 inchs bigger diameter

OldManZ350

iTrader: (23)

Thanks for the Compliment! I've been around the Block a few times myself, but I'm not here to boast. I have a Fairly Heavy backround in Automotive Engineering as well.

So, instead of saying Loose or Tight, can you please Post up Your Numbers for Mains and Rods +/- .0002 in Vq35 Motors, for Street/Strip FI and Full Race FI.

Thanks
TimRod

jerryd87

iTrader: (4)

my personal engine i run .0035 on the rods and had one that came in at .0036 and .0038 on the mains with one .0037. For travis's engine the clearances where kinda all over between .0032-.0035 on the rods and .0033-.0036 on the mains wasnt nearly as happy with the machine shop i used here the second time(im guessing two different people did the work we had other things we wernt happy about either.

i prefer to spec things by power then track/street when you get to a certain power level its just a race engine that just so happens to be driven on the street. 500-650 ish i would try for .0030-.0033 rods and .0032-.0035 mains and run 10w30 rotella, as it neared 650 i would move towards the bigger end of the spectrum and possibly run 15w40. 650-950/1000 i would run .0033-.037 on the rods and .0035-.0039 mains and it would without a doubt get the 15w40 again moving towards the big end as goals neared the upper limit.

on a vq 1000-1300 i would run .0043 rods and .0046 mains and run 25w50 oil, past that i would swap engines, but thats because i feel past that their is too great of diminishing returns due to increasing power but reducing width of the power curve so i would move to a larger engine.

Resmarted

iTrader: (2)

I would agree. Although one could argue that due to the less traction on the street you have a lower load on the engine allowing for tighter tolerances/weaker parts on the street. Generally though when people refer to street it just means the equipment won't see the powerband often.

jerryd87

iTrader: (4)

ehhhhh that would depend alot on setup and tires, i would rather not risk a customer ruining a engine on the basis i THINK they might see less load im going to build it so i dont have them coming back with a spun bearing or blown up engine.

OldManZ350

iTrader: (23)

So with your specs, on a 650-1000 motor, how many miles would you expect to get out of it?

Also how many miles on your personal engine?

Resmarted

iTrader: (2)

It's going to vary obviously for the bearing material, driving style, track miles etc...

I know mine is supposed to last 15k ish. 20 wouldn't be too unreasonable.

jerryd87

iTrader: (4)

on a 650-1000 motor i would expect 20-30k miles depending how often its pushed into that range, if its only raced once a month or something like that i would expect at least 50k and then bring it in for fresh bearings and check the compression.

my motor is somewhere around 10-13k miles now i dont know exactly since i dont have an odometer any longer, it was about 9kish on the motor when i pulled the stock cluster about 9ish months ago and all 9k of that it saw 600whp at a bare minimum every other day with every weekend seeing 30 minute sessions of repeatedly doing 20ish-170-020ish with 30-45 minute cool downs and that would happen about 4-6 times. would also see some regular fun at high boost which is ~850whp based on fuel consumption just for fun since it just burns the tires off the car, im not easy on it at all

bjmax

Some extra info

bjmax

Ok. I think 0.003 is better. But can some of you who have high HP and some mileage on his car put it in a list then we know...

Name…………….Clearance main / Rod …………..Oil W and / oil temp F / Standard oilpump..…Miles……....WHP…………… still running ……….Cause
jerryd87………...… 0.0030 / 0.0030 ………………………………..…………………………………………….......….10-13k …...600………………...... Yes …………….
BJMax1………………0.0017 / 0.0018 …………………………………....10w40 / 266 / Yes………………….. 1.5-2k …..…630 ………………….… No ………………… Rod bearing.
BJmax2………………0.0028 / 0.0030 ……………………………..……..10w50 / 230 / Yes ………………… Zero New ..>650 …………………Waiting to start on this topic.



This is only for the VQ35DE I think this can safe us towing cost for all who is going for high HP. So Help out..

jerryd87

iTrader: (4)

im actually running a bit more clearance then that .0035 rod and .0038 main with the one flyer on each. with 15w40 rotella for oil, 140-180 degree oil temps depending on what im doing(once in awhile it hits 190) with the revup pump

jerryd87

iTrader: (4)

btw modifying the block to accept the HR pump will also allow a higher volume since it has a thicker rotor and rotor/gear thickness is what determines the volume of a pump, its something im going to be looking into when i have my engine apart this coming winter and hopefully by then i also have a mill so i can determine if building a new pump is better or if the HR pump and be truly converted. my only real concern is the crank snout and timing components.

bjmax

Wow 190.. That's hot the oil is than almost as thin as water and at fp.

str8dum1

iTrader: (11)

170-190 is pretty standard operating temp that the oil needs to get to burn off the water and carbon. 140 is too cold.

bjmax

190F i think 190 degree not.. He is talking About degree or Iam mixing it up.

bjmax

Update

Name…………….Clearance main / Rod …………..Oil W and / oil temp F / Standard oilpump..…Miles……....WHP…………… still running ……….Cause
jerryd87………...… 0.0035 / 0.0038 …………...…………………….15w40 / 320 /revup.……...…...….10-13k …...600………………...... Yes …………….
BJMax1………………0.0017 / 0.0018 …………………………………....10w40 / 266 / Yes………………….. 1.5-2k …..…630 ………………….… No ………………… Rod bearing.
BJmax2………………0.0028 / 0.0030 ……………………………..……..10w50 / 230 / Yes ………………… Zero New ..>650 …………………Waiting to start on this topic.