Plastic Fantastic 2

VetteMod - Corvette Restoration, Modding & Performance Forum

Help Support VetteMod Forum:

the biggest 'it sucks' about living where I do is I'm the only guy who's building his own stuff.... when I get the wrong parts or whatever, I'm days from a retail solution.... which usually isn't a problem.

but problem
ixv7odjh.jpg

and the other 'issue'... the intake pushrods, I ordered the wrong ones... should have ordered 3/8"x8.350x.135.....edited
DBoImIRh.jpg

bright side is the girdle seems to fit.
FqbUkNah.jpg

I may have a solution tomorrow - there is one store that's 1 1/2 hours away - but stocked? yeah, we will see.... if not, Summitedited
 
Well I’m impressed, I know I would not have tried an engine build.

Have you searched to see if these heads are prone to causing the issue? The C6 z06 was plagued with valve issues and someone mentioned there was also a head machining error compounding the problem.
 
Well I’m impressed, I know I would not have tried an engine build.

Have you searched to see if these heads are prone to causing the issue? The C6 z06 was plagued with valve issues and someone mentioned there was also a head machining error compounding the problem.

The LS7 Z06 problem was indeed a machining issue. Some of the heads coming from the Canadian company that cast and machined the heads had some of their equipment out of calibration and, for a period of time, some valve pockets were not concentric with the valve guides. This caused the valve stems to wear excessively, and in some cases, would put enough strain on the valve head that it would fail. I have 2 sets of LS7 heads - one was perfect and the other had to be re-machined to center the valves. GM estimated that one out of every ten heads built between 2008 and 2010 had this problem, but the failure rate seems a little higher than that to me. My heads that required re-machining were built in late 2010 (Sep) and factory installed on a 2011 motor. I pulled the heads with less than 3000 miles on them when a "wiggle" check revealed excessive valve guide wear.
 
Well I’m impressed, I know I would not have tried an engine build.

Have you searched to see if these heads are prone to causing the issue? The C6 z06 was plagued with valve issues and someone mentioned there was also a head machining error compounding the problem.

The LS7 Z06 problem was indeed a machining issue. Some of the heads coming from the Canadian company that cast and machined the heads had some of their equipment out of calibration and, for a period of time, some valve pockets were not concentric with the valve guides. This caused the valve stems to wear excessively, and in some cases, would put enough strain on the valve head that it would fail. I have 2 sets of LS7 heads - one was perfect and the other had to be re-machined to center the valves. GM estimated that one out of every ten heads built between 2008 and 2010 had this problem, but the failure rate seems a little higher than that to me. My heads that required re-machining were built in late 2010 (Sep) and factory installed on a 2011 motor. I pulled the heads with less than 3000 miles on them when a "wiggle" check revealed excessive valve guide wear.

Thanks for mentioning what the LS7 head problem was. I've read no shortage of posts (elsewhere) complaining about problems with those heads, but I never saw a single post that actually identified the cause/reason for the issue.
I appreciate it. :thumbs:
 
As an Amazon Associate we earn from qualifying purchases. Product prices and availability are accurate as of the date/time indicated and are subject to change.
Great updates- sorry been away a bit - in Annapolis - trying to pass the sailboat along to another cruiser. Been in the 30s here - even tho the wx has improved in Fl I could be making some progress.:noworry:

The grills look nice - have you considered using some flat black rattle can?
The Australian outfit that makes "mini-lite" replicas may be back in the swing of building wheels. You could probably specify the offset/BS - and they look sooo cool and old-skool racer.

Cheers - Jim
 
why am I taking a picture of the oil pan? to show I managed to reattach it without a leak? uh. no.Ever wake up in the middle of the night and think "did I tighten the oil pump bolt?"then spend a solid 3 days deciding whether it mattered or not..... it was snug, not 65 ft lbs
7ImWNebh.jpg
and I'm not blowing another motor on an oil issue... at least not a preventable one
last time I got it apart without having to change the gasket... not so much this time
Qa2x4nkh.jpg
I think I figured out the problem with the lifters... look at the wear marks at the end.They would have been fine if they were the 210 degree tips but because that tip.... also see the wear mark in the exhaust rods? I also ordered adjustable guides... and longer pushrods (intake, I already have longer exhaust)
Mzjrv7wh.jpg
then signal time
iEIGPnxh.jpg
5NzcM4Th.jpg
all pretty
3fjEYQOh.jpg

and there we go
DdxzKemh.jpg
​​​​​​​
 
Great updates- sorry been away a bit - in Annapolis - trying to pass the sailboat along to another cruiser. Been in the 30s here - even tho the wx has improved in Fl I could be making some progress.:noworry:

The grills look nice - have you considered using some flat black rattle can?
The Australian outfit that makes "mini-lite" replicas may be back in the swing of building wheels. You could probably specify the offset/BS - and they look sooo cool and old-skool racer.

Cheers - Jim

I decided I didn't like them 'flush' so onto the next revision

I love mini-lites but not sure I like them in an 18" or larger size.

I still have the bent wheels - timing to get them back is problematic.... and I do like the look.... be pretty easy to get them straightened now...
 
next day means next day if there isn't someone else to blame.... which means I don't have pushrods or valve covers... but I have plenty to do.

I worked on the trailer a minute - but mostly it just needs a bath and it's ready to go.. in other news

linkage needed adjusting.edited Love how easy Hurst is to adjust
stick a 1/4" bolt in the middle
hSTB1tUh.jpg
then find out why your reverse doesn't go easily (that was the only issue other then a linkage spring has joined the nether.
qjpsm3Fh.jpg
next was bleed the brakes with DOT 4 fluid
TiD3ICYh.jpg
thankfully my tools suck
MTLXwADh.jpg
what was interesting was the front system was a bit low.... no leaks, so probably just residual air bubbles...edited
akQXgJoh.jpg

I also got as far as I could without the intake pushrods
fbB4Fiqh.jpg

hopefully tomorrow ... UPS claims there was severe weather in Illinois but whatever it was didn't make it to news here...editededited
 
I always thought those funny circular spring clips for the linkages were a weak link, i am actually surprised they didnt fall off more often
 
thankfully, the parts arrived today - and I quickly got to painting them....edited
8VRUzfuh.jpg
dNzKA1oh.jpg
then toss in the pushrods - finally, even a blind squirrel finds a nut
CQITxNeh.jpg
I was a bit concerned after the fiasco of the other rockers not fitting that it would be chinesium measurements... nope, fits just fine
YM34qVAh.jpg
thick cork gaskets
YOc7Y6Uh.jpg

and they don't fit
APTrcach.jpg
P03g8dih.jpg

thankfully I have hammer and fire
M7NMIB6h.jpg
uTN2xePh.jpg
and epoxy - I could attempt to weld them but with the paint there and unknown metallurgy, epoxy is the best option
pkTiXlLh.jpg

tomorrow, noise
​​​​​​​
 
i like the valve stud girdle, how does the attachment work?

does it bind down on the jamb nut or does it have its own valve adjusting system as part of it?
 
i like the valve stud girdle, how does the attachment work?

does it bind down on the jamb nut or does it have its own valve adjusting system as part of it?

there are 'special' poly locks that come with the girdle. basically, they're just a taller poly lock.

it works by interference .... I probably should have shown that step - the girdle floats on the poly locks - because the rocker studs are at different degrees to each other, there's a float point which then mechanically holds the girdle in place (imagine a V with a bar across the legs - there is a point where the bar would naturally stay).

Why I should have video'd it.... the driver's side basically slipped into place, but two studs on the passenger side, rear, were slightly askew.... not much but enough that it made it a challenge to get it in the right spot.... I won't say I used a slide hammer to move it to where the clearances were right, but you wouldn't be wrong to assume I did.... on that side, it is interference fit.... but optimally it'd be like the driver's side where it floats just at the right spot....

the other issue was the valve covers were only tall enough with the cork gaskets and some quality hammer time.... I swear they should say "will 'fit' rather then fits"
 
thanks for the explanation, thats interesting letting the studs creating the binding point. What do they get torqued down to 40-50 ft lbs?
 
thanks for the explanation, thats interesting letting the studs creating the binding point. What do they get torqued down to 40-50 ft lbs?

the rocker studs? I dunno, to 'that'll hold' or 'good enough'? I suspect that's fairly low number because it's a 3/8" bolt in the aluminum head... 25lbsish?

the poly locks get adjusted to whatever the spec is for the cam, my case, .016 cold lash, then tighten the allen bolt then tighten the bolts that through bolt the girdle.... to be honest, I'm not sure why they need to clamp. Side benefit is the poly locks can loosen under use so the clamping adds a layer of protection against that....
 
Tonight's story... don't cheap out, or avoid Speedmaster... sorry Aussie friends, this stuff is junk.

for a complete score: Number of parts from Speedmaster (rockers, guides, intake, valve covers, pan)... number of those parts that didn't work.... all of them, in tonight's update
Rockers

I got the car back together but the rockers got noisy just after I started it.edited The Speedmaster valve covers were leaking too...edited
but first, rockers
see the machined point in the trunion?
P8hrLeMh.jpg
now look at the poly lock - see how it's worn - the hole is interference fit (including for the poly locks sent by Speedmaster).... turned them over and hopefully there's enough thread to hold them in place for the weekend - but when the weekend is done, I'm replacing the rockers maybe even screw in stud
ld2dAFsh.jpg

a nice picture of it apart for posterity - I had to turn the trunions over to the 'wrong' side
7fHxRVbh.jpg

in other news, chinese heads.... I still think the casting is worth it, but next time I send them for a quality build.... this hole (of course the rearmost, wasn't fully tapped)
Qj9dJIgh.jpg

they are cheap valve covers.edited They fit, but they used tubes to inset the bolts.... not exactly sure why but the problem is due to the tube's thinness, the head of the allen bolt deforms the tube (thus loosening the cover over time - 3 ugga duggas for the win)
Js8bSpUh.jpg

this wasn't Speedway's fault, but there was a major amount of clearancing that happened
P03g8dih.jpg

it really seems like the Chinese companies have given up - it used to be you could carefully pick but now? I haven't gotten a part from a Chinese company which didn't require work to make it even work....edited
 
Went to the Optima Challenge at Las Vegas and checked out your GTV competition. Camaros with LS7s pretty much ruled. As a side note, Chris Ramey who had dominated GTV with his C-4 switched to GTL (less than 3200#). He had to remove his wing since it did not fit the GTL rules, and he pretty much got his lunch handed to him. Not sure it was the wing, but he didn't fare well against cars he used to beat when he ran GTV. How did you autocross sessions go?
 
I'll debrief later... hopefully this link will work. Just mark me 'done'.... up at 5:30, Ax in the morning, shag cones for group B.... drive 5 hours home through a 65 mph dust storm then snow in the mountains.

my Corvette is not waterproof... heck, I'm not even sure water resistant... I guess I got 2nd in novices....I'll post that up later too :zzz:

https://onedrive.live.com/?authkey=%21AFlIYrV45G0Nt4g&v=photos&cid=CC18730F4D55AA7B&id=CC18730F4D55AA7B%2182050&parId=CC18730F4D55AA7B%2182049&o=OneUp
 
To Do - while I remember

1) fix the sticking clutch
2) connect the speedo sender
3) firmly attach overflow
4) better throttle cable (sticking)
5) fuel leak out the top of the gas tank
6) better gears.... 3.42 or 3.73.....
7) trailer ramps
8) tire rub front.... thinking much stiff springs all the way around
9) front signals
10) fix oil coming out on hard left handers

11) figure out if someone let the air pressure out of my tire... right rear was flat when I got to the track... filled it, it's remained up ever since....
 
Last edited:

That looks pretty good - you were smooth! Body roll appears to be well contained and there isn't too much dive under hard braking. I am impressed with the way the rear suspension appears to be working. I did see a little fender rub on the right front. Did you feel any tendency to understeer/oversteer? Next step needs to be some higher speed stuff on a road course.
 

That looks pretty good - you were smooth! Body roll appears to be well contained and there isn't too much dive under hard braking. I am impressed with the way the rear suspension appears to be working. I did see a little fender rub on the right front. Did you feel any tendency to understeer/oversteer? Next step needs to be some higher speed stuff on a road course.

Oversteer when I started pushing it.... but I'm mostly certain that was 90% steering/throttle meat-sack 10% car.

yep, it rubbed on both sides when turning - not a lot, but a bit... I need to check the spring rates - I may have put a higher rate on the back... I'll upload the video from inside the car where it got a bit wild (my last run)

now live
https://youtu.be/fNEQn1CE75I
 
Last edited:
nice ....was the smoke the tires rubbing or the oil burning off?

i need to do that with my adult kids that looks like a blast
 
nice ....was the smoke the tires rubbing or the oil burning off?

i need to do that with my adult kids that looks like a blast

I can correct my earlier statement... brake fluid was the culprit (and it 'should' be sealed now)


Buy a Miata, put them in it, they'll never get back out. I love my Corvettes, but if I was only doing autocross.... Miata or even better, Honda2000 - but they're a lot more money to get into (2k v 10k in comparable condition).
 
you know that list.... well, there's 14 items on it after completing 2..... ah well, ordered more bits to knock the list down
first things.... all 4 springs are 12" 400 lb springs.edited So the hope of changing springs... nope, even my spare springs are 350 lb... ah well, 4- 500# springs on their way
Z31mGbfh.jpg

where is the tire hitting... on the right... here (between the tape marks)
7drLfqvh.jpg
on the left... just a light rub where the tape is - this is the wheel I had to fix the opening....
B26EdQDh.jpg
the worst of the bunch
2ocBK41h.jpg

clearly I don't have control over the rear tires.... but I do have the poly bushing so this will be ended...
IbSiKydh.jpg
there is a clank problem as well - but I'm beginning to think it's just a noisy limited slip

the other issue is spring bind is stopped the tire... there needs to be a progressive stop installed... so that's a new item to the list
om2d9nch.jpg
where the bump stop needs to be....edited
N6mAaf0h.jpg

I'll take the springs out completely when I set the bumps in place so no more rubbing.... and travel.editededited


hmm... fuel leak
8PjFKpPh.jpg
I'm starting to suspect the leak is the fuel pump seal.... that's a lot of money and work to replace something that should never have this issue... not 100% sure, but ...hmm
FJHzVcmh.jpg
UJQnORvh.jpg
maybe you folks see something I'm missing
TzkyEHjh.jpg
YjHkpc7h.jpg
 
You need to get on a road course at some point. The downforce (and spring loads) will be higher at 130 mph than at autocross speeds, but you will turn the front wheels a lot less - unless you are already in big trouble LOL. If you add any aero, that will also change things and require higher spring rates.
 
Back
Top