Issues with my Motor need help

[93ls1rx7]

I have a Solid Roller 408 iron motor running 14 to 1 compression, a vacuum pump, Victor JR, Race Demon carb, AFR 225 heads ported by TEA (Flowed over 330 at .600).  It a an LS1 SBC motor.

CAM is a 268/275 .715 lift and I believe a 112ICL

Here is the issue.

The car made right at 500rwhp through a powerglide and a 5300 stall on the first full pull. First issue is that, EVERY pull the car has done, the HP curve is climbing fast until it hits 6200rpm where it goes dead flat and wont rev any higher. (Motor was built to spin to 8000rpm) Never peaks and just flat lines everytime at 6200rpm. When the car was EFI we (Mikey from Rapid Motorsports) thought we were running out of intake. Thats why I went to the carb setup. She was on the Dyno this week and did exactly the same thing. Pulls up to 6200 rpm and will NOT go any higher.

No idea why? Maybe cam is wrong??

Engine builder sent me a complete long block that they said they checked everything on assembly and they spec'd all the parts so it wasnt me picking mismatched parts.....

Second issue is almost more disturbing. The first pull the car made on a dyno jet it made right at 500rwhp at 6200rpm. Next pass it made 486, next pass 466 and so on. Mikey tried everything possible and by the last pull the car was only making 410rwhp with a solid 12.8ish AFR.

Mikey thought maybe the lash was off or the Cam sensor was bad. Well I checked the lash and it was off a little so I reset the lash to .023 cold and .018 hot (What builder told me to do) and replaced the cam sensor.

I took it to the dyno this week and the car STILL wont make it past 6200 rpm with a nice 12.8 to 13.2 AFR.

It also only made 385rwhp on a mustang dyno which is probably right around the 410rwhp it made on the last pull on the dynojet, maybe a tad higher.

I am so frustrated. It has been over a year farting around with this motor and I feel like I am farther away from being done no than I was a year ago.

Anyone have any ideas?  I WANT TO RACE AND STOP WASTING TIME AND MONEY!!!

[Randy H]

Have you checked the valve springs?

Randy

[fastfairmont]

have you checked p/v clearance on overlap? mine would get to 7300 and just laydown like it was on the rev limiter. found that it was the intakes hitting the pistons, had to replace all 8 valves and change the cam. it had plenty at full lift but when the exhaust is closing and the intake is opening and the piston is on it's way up to tdc it only had .028 on the intake. also your lash seems to be backward. normally you set them tighter when cold because the lash will loosen when the motor is hot, especially with aluminum heads. also i would not worry too much about the dyno numbers. it can be real hard to get accurate, repeatable numbers with an automatic with a loose converter. do the math after you can run the car and you will get a better idea of what kind of power you are making from your et and speed related to your weight, tire and gearing. good luck

[LarrySantucci]

Pull the chip out of it and see what it revs too.

[Richard Maitre]

Yea I would check the springs first, make sure they are all above 240-250 on the seat. Has it been to the track yet? Thats your real test.

Rich

[93ls1rx7]

Yea I would check the springs first, make sure they are all above 240-250 on the seat. Has it been to the track yet? Thats your real test.

Rich

How would I test seat pressure?

It hasnt been to the track yet.  I was going to go today but the weather is junk.

The rwhp isnt so much of a concern.  The concern is that it lost 80rwhp over the course of the pulls and that it wont spin past 6200.

[93ls1rx7]

have you checked p/v clearance on overlap? mine would get to 7300 and just laydown like it was on the rev limiter. found that it was the intakes hitting the pistons, had to replace all 8 valves and change the cam. it had plenty at full lift but when the exhaust is closing and the intake is opening and the piston is on it's way up to tdc it only had .028 on the intake. also your lash seems to be backward. normally you set them tighter when cold because the lash will loosen when the motor is hot, especially with aluminum heads. also i would not worry too much about the dyno numbers. it can be real hard to get accurate, repeatable numbers with an automatic with a loose converter. do the math after you can run the car and you will get a better idea of what kind of power you are making from your et and speed related to your weight, tire and gearing. good luck

I may pull the heads.  Like I said I am not worried about the dyno numbers I am worried that I cant get the motor over 6200 rpm.

As far as the lash, I thought the same thing.  I called the builder MANY times to double triple check....maybe I will pull the heads and call COMP cams and ask them what to degree it at.

Any other ideas?

[93ls1rx7]

have you checked p/v clearance on overlap? mine would get to 7300 and just laydown like it was on the rev limiter. found that it was the intakes hitting the pistons, had to replace all 8 valves and change the cam.

Well it looks like you win the prize.

http://www.torquecentral.com/showthread.php?p=335841#post335841

If you look in that thread you can see the #2 and #4 intake valves were hitting the pistons.  #6 and #8 look to be ok.

Time to go pull the drivers side and see if I find any more.

[fastfairmont]

sorry to hear that. you may be able to fix the problem by re-timing the camshaft. if you retard the cam a couple of degrees it is possible to gain some intake valve clearance but you will lose some on the exhaust. with the cam i was running that caused my valves to hit i was unable to get adequate clearance and i changed cams rather than cut the pistons.

[93ls1rx7]

I am up in the air on wether to degree it and hope or flycut the pistons.

One other thing, should I replace ALL the intake valves?  4 are hitting for sure.  Best to replace all of them I assume.

[Richard Maitre]

Sorry to hear sir, let me know if I can be of any assistance.

Rich

[93ls1rx7]

Rich
I may give you a yell.

Hey with the valves kissing the pistons is there a chance that the guides got damaged?  How about damage to the valve seat?

If the builder wants a shop that specializes in "Heads" , I may bring them up to you to check them out.

[fastfairmont]

have them all checked. i thought that mine were just 'kissing' the pistons and then found that seven of the intakes were bent. bought all 8 and had them lapped in. it was an unexpected expense but now i know it's right and not going to hurt anything else.

[93ls1rx7]

The builder is saying is CANT be valve float. :roll:

[Richard Maitre]

Most likely the seats arent hurt, but if the guides did get tweaked you are gonna need another valve job anyhow. With them just kissing they wouldnt have broken maybe just pushed. Have no fear its all part of this stuff, sorry. And you can never say its not float, depending on the cam profile, it may be agressive to where its hard to keep the follower on it.


Rich

[93ls1rx7]

The head builder thinks the rod bearings are wiped.  

He said that even if the valves ARE hitting it woudnt cause a 100rwhp drop on my car.  I cant see any gap between the valve and seat so he thinks improper rod bearing clearancing.

The builder is going to look at it and make any issues right that may be wrong.

[fastfairmont]

when we looked at my valves you could see on the seat that they were'nt seating evenly all the way around. i did a leakdown on mine before i pulled it apart and it did all single digits even though the motor was cold and there was no air past the valves. with 250 lbs of seat pressure it will still look good but when you pull the valves the seat on looks like shit. i think if the rod bearings were out of it it would make noise and be losing oil pressure and then seize when it got hot. if the valves are hitting the pistons you have probably also bent the pushrods and if they are bending more as you make all those pulls it may explain why the power is falling off. roll the pushrods on a piece of glass and see they are straight or not.

[nova10sec]

That rwhp looks good, mine made 444 with a loose converter and ran a best of 10.2's, so with 500, I would think you have a good 9sec run in her.

Did you check the lifters, I wouldn't think you could hurt the cam so easily but the rollers may have suffered..

Good luck

[fastfairmont]

good idea

[93ls1rx7]

I dropped the pan last night and there were a lot of BIG chunks of aluminum.  Pieces probably a quarter of the size of dime.

I didnt pull the main caps or the rods but something aint right in kansas.

The side clearance on the rods was only about .013 which seems tight to me.

[fastfairmont]

it seems like you have a lot of problems. maybe your p/v problem was also related to your aluminum rods growth noy being allowed for. i hope that your builder does right by you. good luck.

[93ls1rx7]

Thanks.  And thanks for the ideas/help guys