I have been chasing poor oil cosumption for a couple of years. All my tests I thought pointed to rings. I was wrong. Here is a picture of the intake valve in cylinder #4. I have a nightlight up the intake port. Compresssion was 125 and leakdown was 65%. The rest of the intakes are similar. This was a 2.0 l head with no cracks when rebuilt.

Here's the solution

It doesn't look like an intake valve issue, it looks like the head has allowed the seat to droop- a common occurance with a 30+year old head casting.. When the head starts to droop the seat follows it and you get poor sealing..

It's easy to check the valve, pop it out and chuck it up in a drill and see if it turns true, if it does its the head...

Some heads are wose about this than others, generally we see this on the exhaust side of things when the EGT exceeds 1350F. Kevin Groot had the same issue at last years runoffs when Len and I did a valve job for him in the paddock- it didn't last long, about 2 laps at mid ohio..
Another reason why we don't use old castings any longer-

You've seen the light!

No more rebuilt heads for you I imagine... How did the seating get so poor on those intakes???

oh, Jake answered whilst I was typing.

Dave, remember a year ago when I told you to look at the heads for some symptoms to the "issues"??

I told ya so!

But I got a sweet set of Nickies for my drag race engine out of the deal :-)

Yep, I remember. Truth is I probably ran a half a dozen leakdown tests during that time and I thought I was getting results that pointed to the rings. That's a classic example of why good studies are set up as double blind experiments. That keeps the experimentor from biasing the results. I was looking for results that pointed at the rings and I got em.

Any body have any suggestions about how to fix crow so it tastes OK.

Dave

drink lots of rum then it tastes fine.

Dave: Salt,Pepper and a little Barbecue Sauce,
or so I have been told

Dave

Now you know.. You learned the same way I did! I made the same mistakes, but I was only 15...LOL

Looks like I need to do an article on the proper way to do a leak down test...LOL

I am really glad that you found this....

BTW- Len can repair that head, but it might happen again down the road..

i'm suprised that engine wasn't fart'n and spitting through the intake.

It is a funny how one only sees what one is looking for.


John

P.S. No one tell Charles....

Yeah, it only cost him 4,000.00 in replaced components and consulting trying to figure out the problems..

I have less than that in it, but months of nights of lost sleep...

How did you miss the massive air leak back through the intake and carb?

The engine has EFI.. He left the air filter on during the tests based on what he told me earlier in the week via telephone..

Dave - I've heard that Miracle Whip, Bleu Cheese and tabasco sauce make a tasty sauce. Then deep fry in Coca Cola. Bon apetit.

Looks like I better start shopping for a good Christmas gift for my favorite cylinder supplier.

Dave

Didn't the motor have an oil consumption issue? I don't see how the valve/seat problem would cause that. Am I missing something or might there be two problems.

Yeah Jake, please explain this whole oil burning issue?

An intake valve (or any valve for that matter) can certainly cause oil consumption..

If the valve is leaking down it can allow pressure past it during the compression stroke and a portion of that can pass right by the guide. That pressure can pressurize the valve cover area and then the crankcase. When this happens oil is further forced past the other valve guides that may be on the intake stroke, this contaminates the intake mixture that enters the chamber with oil. What makes it worse is a piston heading to BDC on the power stroke with a valve thats not seating draws OIL past the guide and right past the leaky valve into the chamber. This made WORSE because the opposing cylinders are PRESSURIZING the crankcase/valve covers making the oil fly by the valves with ease.

Chances are that since this valve didn't seat well that it REALLY worked on the valve guide because the valve was bouncing sideways every time it tried to seat. As the guides wear they let MORE pressure by them on the intake and power strokes, worsening the issue..

So there ya have it, this type of issue happens all the time and head issues are initially troubleshot as cylinder/ring issues when they really are not... Every action has an equal reaction elsewhere within the engine..

My hat is off to Dave, he has stayed with it and his perseverence is noted. He has to be the most hardcore engine kit customer I have ever dealt with. He is treating his son to a righteous education in engine operation..

BTW- Dave what all of this tells me is the power you experienced with this engine on it's BEST day was no where near its potential. The intake mixture was being contaminated and efficiency suffered from that... Now that you are adding the LE 200 heads you will be a totally different world...

Dave put that engine back together very carefully. do not put it in your car!

i'll be down next week and we can swap my little 1.8 in yours and i'll take that lemon of yours off your hands free of charge! that engine will be just to much trouble and have to much power for you and your son, i'm putting myself out here like this because you folks are good people and i'm just trying to help out.

and just think how nice it will be to have a worry-free L-jet running all by itself with no tinkering and tuning to have to do!

Hands off clutch killer

the one spring off intake valve i saw rattled around in the guide like crazy. literally rocked back and forth. the new heads sure look swell dave. the oil burn pattern on the pistons was like a trail on the piston top. do you have some of pistons 1&2 dave?

k

Jake, you're right. Dave definitely has some serious potential left on the table in that motor. I drove it before the Bug-O-Rama you were at and while impressive, I could feel that it wasn't living up to its potential.

Dave, get ready for some serious power. Gerry is going to have to learn how to AX again.

I smell a speeding ticket as a result of this build.

Hey Jake did you include a free get out of a ticket card with those heads?
You know the one like you used on your trip.


Jake since you have my parts in your shop I might be lookig at a set of heads too. Do you have any LE190's on the shelf to ship this way when all is ready?

Just getting ready to head out in the garage. I'm gonna CC the heads swap over hardware and study how to vent the valve covers. These head have the CHT threaded into one of the holes for the tin near the intake for #3. Unfortunately thats right were the boss is for the rocker ventilation. I'm not sure if all that won't be just too tight.

Another option might be to put the sensor somewhere else or use a different sensor and recalibrate the fuel injection.

Dave

Are you going install the new heads and recheck leakdown ?

I WISH we could keep heads in stock, thats something we just can't do no matter how hard we try... Between the engine shop eating them up and the craze currently happening with engine kit sales on top of individual orders for them we have a 3 month wait, it'll be 4 months soon if we keep selling kits at the current rate.

Joe, I do think that you'd benefit from a LE 200 head if you bump the CR up a tad. I base this on some recent findings that really woke up the 2056 line of engines..

Jeff

I was sure thinking about it before I split the case. A good set of numbers would sure feel good.

Dave

not to hijack...can i have the mods done to my set? i'm not worried about the shipping or addition labor. i feel the other minor matter might be addressed at that time as well. back too your regularly scheduled programming.

k

Right about now someone like JP will chime in '..now don't you wish you'd gone SIX'

Shoot, sixes break too!

There are always some problems when building an engine, 4 or 6.

Who did these heads? Local guy?

Len did the heads 2.5 years ago...They were based on 039 cores that Dave sent in for the purpose...

Issues like this are not common, but 2 liter cores do sometimes have issues similar to this, no matter who does the work to them. Some 2.0 castings are worse about this than others...

The issues could be repaired, but Dave did what a wise man would do and bought a set of brand new castings- it'll take them 30 years to get to the point of his old castings :-)