ajrothm

In preparation for my Winter track visit, I managed to hurt the motor with a loss of oil pressure during a test pass, I had the data logger running and it lost oil pressure at 6000 rpms in 3rd gear...
I finally got it all out and to the builder today and we tore it down to find the issue. Before we started, the builder told me what he thought it was going to be, sure enough he was dead on correct. The Callies Compstar crank flexed and ate the number #4 main bearing. He said he has seen this 4 times this past year in over 900 rwhp cars, particularly blower cars.

So this thread will be the rebuild/rebirth, a few minor upgrades and a better foundation for more power down the road. But first, the death:

Oil pressure drop is the gold line in the middle of the chart..from 65 psi to 35 psi in a blink...And shes done...




The teardown begins:












Nasty a$$ cradle

ajrothm

Kill shots


#4 Main bearing




#4 Main journal with the wiped bearing, only on one side of the journal...(ie. flexed)


#1 Main bearing.. Starting to show some wear, figured it would be worse considering the blower belt tension on the snout of the crank.



Rod bearings looked 98% perfect, only minor scratches in the coating alone...(due to the floating debris)


Heads were perfect after tons of abuse at 900 rwhp



Pistons were perfect, cylinders just had some minor scratches from the imbedded copper bearing material





So aside from the obvious bearing damage, the rest of the engine looks like it had barely been ran, even though it had over 8k miles on it and countless high way pulls at 850+ hp minimum. Had the crank not flexed and wiped the bearing, this thing would be in great shape.

I had a conversation with Callies in regards to this issue, they basically stated that the Compstar line of products should not be used over 1000 CRANK hp, and he really didn't even recommend it at 900 crank HP.. (although 2 years ago they were telling me something else)... The Callies rep told me that flex is a pretty common issues with the Compstar cranks, especially with a blower driven off of it and pretty much said a Dragonslayer is the minimum they recommend for 800+HP blower applications.

Nice to know...NOW...

SBCGENII

Keeping the F1R?

corvette8189

That sucks, an all to familiar sight.

ajrothm

Build plan:

NEW:
Dragonslayer crank
Ultra H Beam rods
LS7 lifters
Melling oil pump
Roll Master double roller chain
New gaskets through out.
Custom BTR cam/PAC springs

Re-use:
Re-use my pistons but have them blasted/recoated, new Total Seal rings, hone the cylinders with the new 2.5" BHJ billet torque plate
Line bore and boil the block
Lightly surface the deck and heads
Clean, inspect and setup up the heads with new PAC tool steel springs.
Re-use my 7/16" double taper push rods and stock rocker arms

The whole engine will be blue printed to the T once again and the cam degreed in. I'll also be sending my balancer/direct drive out for the cog belt mod and installing new bearings in everything. Basically getting the blower drive system 100% perfect before the blower upgrade which will probably be later in the year to an F1X. I still want to get it into the 8s with the F1R before I change it... I'm hoping I get some power with the custom cam and see lower boost pressure, at that point I will over spin the blower a bit more to wring everything out of the F1R I can get. I'm hoping for a 155mph+ trap speed at 3600lbs.

4DRUSH

Well that sucks, but a least you caught it in time

Milan

You really think the double roller chain is worth it over C5R?

ajrothm

Grunt work begins... I've got a LOT of clean up to do on this this engine compartment.




Dropped the trans/diff so I could remove the TT to inspect the couplers and measure the input shaft for run out as I suspect its slightly bent. RPM poly couplers still look great after about 8K miles.


I'm going to clean and paint the engine compartment again, as well as shrink wrap some wiring. Last thing I want to research is an intake manifold swap, I know there is not a lot to gain in intakes but its something I'd like to do if I can for a bit more power and cosmetics. I'm not going to spend $3k on a sheetmetal or anything but...Maybe a holley mid ram or something...We'll see.

ajrothm

Billy I thought about you when this happened, I even mentioned your ordeal to my dad today while we hauled stuff everywhere... Yes it definitely sux... Especially since it was an "upgraded" part that failed.

Yeah tell me about it... Now after building this engine twice, I'll have a TON of money in it, yet its still a stock 4 bolt block..

I had the Roll Master double in it previously, it had a little more slack in it then I preferred so we ordered a new one...Not to mention the copper bearing material that is impregnated into every freakin thing in here.

Chris Stewart

Yeah that sucks, thanks for reminding me I'm still running a stock crank.

winters97gt

Me too, but you're not yanking on it Chris with your setup.

Good luck Alan. My girl stopped by the shop and my junk is stuck in a corner, no work being done. Bit frustrated but I'm sure it will be worth the wait.

slow ride

That sucks, I've heard about that more and more lately. I wonder if it's only the 4" crank or longer that has the problem.

I always have to bug my machine shop guy and sometimes go in to his shop and do it myself. I don't save any money, but it's the fastest way to get something in and out.

robert miller

That is crap man. Glad you got off of it in time to safe parts. Looks like you have a good hand on her. Robert

blown81bu

Im in the same boat..i like how the coils are off the engine and in the fenders such a cleaner look..one more mod i will add to mine..stock engine mounts?

Is it easier to pull it from torque tube or bell housing bolts?
I lowered my cradle some removed heads and got at bell housing bolts

We have alot of similar parts..very cool build

ajrothm

Mark didn't they already have the engine back from Thompson? Wtf are they doing? Put the b*tch in and get it running already.

After the conversation I had with Callies about the Compstar line, I would never buy them again, I think your better off with a stock crank.

Apparently crank flex is the real deal tho..

Proace4

Why make the jump to an F1x? I had a thread awhile back and the consensus of the cf, was that while it may make power, its not a reliable/efficient choice. That it's not designed for a "street car". Why not switch to a YSi pullied to the max? Just curious as I know you have a well thought out build...

ajrothm

Well honestly, I go back and forth.. The quest for more power, yet tired of breaking crap all the time and sinking my life savings in this car. The F1X is plenty reliable when it's not over spun way past its max.. (Which isn't needed really anyway given the power it's capable of). My F1R has been a very reliable head unit, I have done nothing but oil changes to it for 8k miles. The F1R hits hard and makes a bunch of boost quick..but it peters out early on air flow and doesn't support enough power at 7k. With my setup, I could throw an F1X on in about an hour and change nothing else.

A YSI swap may make a tad more power to the wheels then the F1R due to its efficiency and less parasitic drag but, not enough to warranty swapping brackets/other components.. If I went to the trouble/expense to swap, I'll go to the F1X. My problem with the X is restricting it enough to keep the boost down to 25 psi or so on a 402" without running a big *** pulley and making the blower lazy from under spinning.

That is a decision for the future, right now it's going back together with the R, hoping the BTR cam will gain me some power.. If I can go 8.80@155-156, I'll be content. I really just want the car reliable and stay off Jack stands for more then 6 months at a time.

ajrothm

What happened to yours? Didn't you just have it at the track a month ago with Doug when the TB acted up? Don't buy a Compstar crank, I'll tell you that.

Proace4

I understand completely. My reasons for switching from a YSi to the X were similar. Plus with the great deal I got, it was a no brainer. I will be running a 4.0/8.0 setup and trying to keep my boost to 25# as well, also on a 402.

I loved the YSi but it wasn't making enough jam anymore and the bearing replacements were getting old. I should be able to make the same if not a little bit more with the X and have it not at full capacity risking failure all the time. I put just over 10k miles on my car last year between all the events and plan to hit just as many this year plus some new ones.

Very excited to see your build progress, it's always been a well thoughtout combo. Goodluck man and save for the X, hopefully I will have some good info to provide come spring.

blown81bu

Im freshening up my engine like u just adding a set of wiescos( still waiting) and updating to 10rib and cog flip drive with a whole bunch of bling