t8fanning
8v are still cool, right?
- Joined
- Oct 10, 2010
- Location
- Vancouver, WA
probably a pretty good assumption
Our engine setups are pretty much the same, so I think I have a pretty good handle on how you think.
-
Hello Guest, welcome to the initial stages of our new platform!
You can find some additional information about where we are in the process of migrating the board and setting up our new software hereThank you for being a part of our community!
Mike K's '79 242 Barn Car Revival
- Thread starter Stiggy Pop
- Start date
Our engine setups are pretty much the same, so I think I have a pretty good handle on how you think.
Duder
Watch it man, there's a beverage here!
- Joined
- Dec 9, 2009
- Location
- Torrance, CA USA
Trying to sound as un-biased as possible, but a 70mm turbine wheel and 76mm compressor is definitely going to be overkill in terms of physical size, for 350whp at sea level on a 2.3L.If I could influence your decision at all without sounding like a corporate shill (which I'm not, at least not that I'm aware of... unless they have programmed me via rally car exhaust chemtrails), I would suggest looking into the G25-660. Turbine wheel is only 54mm inducer but is a high-flow, low inertia brand new design that is not a carryover from anything else. Compressor is 67mm exducer with a wide 79% - 80% peak efficiency island and enough flow to make 500 - 600bhp. I'll let you look into it and try not to influence your decision too much. But I'm here if you have questions (and I get no commission!).
Stiggy Pop
In the cool kids club
- Joined
- Feb 27, 2011
- Location
- Granville, MA
I wasn't holding any bad blood, hope you aren't either (if so apologies from my side).
Actually having you weigh in is very valuable to me. I reached out to Pat via PM but haven't heard back from him. You would suggest going back to a stock bucket and shim setup? That's disappointing for obvious reasons, but I invested so much in this casting that I just have to do what it takes to make it work for me. Any thoughts on the head being machined to compensate for the springs they used? Simple as putting a hardened .060" spacer in the bottom of the seat to get back to stock spring height?
getting that deep into the head might preclude me from budgeting in the turbo... harrumph
If I could influence your decision at all without sounding like a corporate shill (which I'm not, at least not that I'm aware of... unless they have programmed me via rally car exhaust chemtrails), I would suggest looking into the G25-660. Turbine wheel is only 54mm inducer but is a high-flow, low inertia brand new design that is not a carryover from anything else. Compressor is 67mm exducer with a wide 79% - 80% peak efficiency island and enough flow to make 500bhp. I'll let you look into it and try not to influence your decision too much. But I'm here if you have questions (and I get no commission!).
I'll reach out to you independently after I sit down and do some research. Obviously happy to hear your input. That is a new series of letters and numbers for me, just popped it into google and might head over to open a gofundme for that price tag
t8fanning
8v are still cool, right?
- Joined
- Oct 10, 2010
- Location
- Vancouver, WA
If I could influence your decision at all without sounding like a corporate shill (which I'm not, at least not that I'm aware of... unless they have programmed me via rally car exhaust chemtrails), I would suggest looking into the G25-660. Turbine wheel is only 54mm inducer but is a high-flow, low inertia brand new design that is not a carryover from anything else. Compressor is 67mm exducer with a wide 79% - 80% peak efficiency island and enough flow to make 500 - 600bhp. I'll let you look into it and try not to influence your decision too much. But I'm here if you have questions (and I get no commission!).
You're right. EFRs are physically large. I also agree that a G series would be great. The only issue is they don't have T3 inlet flanges as far as I know. He could use a T3-T4 adapter (like I do), but I don't know if he likes the idea of that. The only reason I didn't buy a G series (and didn't recommend one) when I was looking for a turbo upgrade was because they only had V band housings at the time.
shoot, I was replying on my phone while sitting in a car at work waiting on a scan tool to do its thing. I did not realize you had a shim under setup. What I would to in that case is put the Ferreas in, shim it for stock length valve springs, and then order the correct height shims for your buckets from SuperTech. They should be available in the thicknesses needed to throw the lash caps away. This is what Bergen ended up doing on his car (not the valve and spring part, but to get rid of lash caps). I think it might also be a combination of the lash caps not fitting perfectly and the **** Si valves which were cut down or something to make it all fit. Either way, new valves, better (proper) spring setup, and get rid of the lash caps and you should be good to go.
Stiggy Pop
In the cool kids club
- Joined
- Feb 27, 2011
- Location
- Granville, MA
OK thanks for this, it really does help. I'll admit I only pulled the one bucket and it's the first time I ever had the head apart. There was no shim, just the bucket and the lash cap. I made the assumption that valve clearance was set by swapping out the lash caps. I'm on the supertech site now and see caps and shims. I need to get a bucket, cap and shim in my hand so I can understand how that interface works without the lash cap there to seat into the bucket. Not able to picture it behind the desk right now..
What you are saying about the lash cap fitting the tip of the valve makes sense to me. An ill fitting cap would certainly create some issues even if the valve wasn't necessarily floating.
When I bought the head I did go back and forth with Pat, who was extremely helpful as well, and have more or less been prepared to replace the valves if needed based on his feedback. Glad to hear there is a path that retains the shim-under setup.
mikezohsix
Active member
- Joined
- Jan 6, 2008
- Location
- granville ma
we're talking replacing both the intake and exhaust valves, or just the exhaust valves?
Sorry I'm not up to speed on what Pat said, but I'm sure I'll learn.
iirc, both the intakes and exhausts in the Stage 3 heads were the crappy Si valves. I would throw them all in the scrap bin and get some higher quality units in there. I know for sure that the exhausts definitely had issues, but upgrading the intakes was so few and far between that I don't remember the story on them for sure (its been almost 5 years since I worked there, so I am working off of faint memories at this point). I know for sure that Ferrea has designs for the exhaust on file and I am pretty sure that they should have them for the intakes as well. Again, I don't remember the exact specs on the heads, but I think they had different intake valves installed (not stock).
- Joined
- Jul 30, 2002
- Location
- Rockville, MD
Definitely ditch the RSI junk valves. All 8 of them before they take out the rest of your engine.
If you order buckets to size from supertech... it will be money well spent.
Also verify the spring setup.
The RSI heads have decent porting but alot of the internal upgraded components were junk, if you upgrade the consumables you will still have a nice flowing unit that will be more reliable.
-Ben
If you order buckets to size from supertech... it will be money well spent.
Also verify the spring setup.
The RSI heads have decent porting but alot of the internal upgraded components were junk, if you upgrade the consumables you will still have a nice flowing unit that will be more reliable.
-Ben
iirc, the buckets should actually be supertech units...the question is whether they are the type meant for lash caps or the proper ones with the recess for 8mm shims in them.
Duder
Watch it man, there's a beverage here!
- Joined
- Dec 9, 2009
- Location
- Torrance, CA USA
I'll reach out to you independently after I sit down and do some research. Obviously happy to hear your input. That is a new series of letters and numbers for me, just popped it into google and might head over to open a gofundme for that price tag
Happy to answer whatever I can. Yeah, can't escape the alphabet soup apparently. Shop around a bit, there will likely be some difference in pricing at various distributors and retailers. There's an internal wastegate version as well which adds more cost, so the v-band / sans-gate housing versions will be a little less.
It's a new family of turbine housings and I'm guessing the majority of customers likely asked for v-band; I'd suspect that's why you are not seeing a T3 flange option. I'm not directly involved with the aftermarket products anymore but I have used these same turbine & compressor wheel designs in other projects and can say performance is quite impressive compared to older stuff. I can see how the absence of T3 flange housings would add some complications here though.
You can get different lash caps that will fit tighter on the valves. I have a set of CB Performance ones that are incredibly hard to remove. The lash caps/shims that you have may not have a deep enough bore to properly locate on the valve, which will cause issues if there is any valve float or bounce.
The cut down triple groove VW valves don't leave enough material past the top of the keeper and create all kinds of issues when setting up the head if you're using a stock base circle cam. I've done it, I don't recommend it.
My go-to setup is to use quality single groove VW valves and a KL Racing cam (that uses a reduced base circle). The VW valves, springs, and retainers are all drop in with the reduced base circle cams, no need to cut the spring seats .060" for proper seat pressure.
The cut down triple groove VW valves don't leave enough material past the top of the keeper and create all kinds of issues when setting up the head if you're using a stock base circle cam. I've done it, I don't recommend it.
My go-to setup is to use quality single groove VW valves and a KL Racing cam (that uses a reduced base circle). The VW valves, springs, and retainers are all drop in with the reduced base circle cams, no need to cut the spring seats .060" for proper seat pressure.
mikezohsix
Active member
- Joined
- Jan 6, 2008
- Location
- granville ma
on the lash cap issue.
Here's my thinking...
- The lash cap could only be displaced/come lose, if the gap between the valve tip and the inside of the bucket opened up. Otherwise, how would it have ended up not on the valve tip? Stiggy has the numbers, but I think we measured the lash cap at about .080 deep. Would have to look at the geometry, but I'm guessing we'd need around half that to get the lash cap off the valve stem.
- How does the gap open up? By the bucket losing contact with the valve tip at high rpm as the cam sweeps past tip. Essentially the bucket is "thrown" away from the lobe.
- why/how does the bucket lose contact with the cam lobe tip? Because the valve spring is not controlling the valve motion, and at the point where the valve is supposed to change direction (max open) from opening to close, the valve continues to open, the valve gear has now "floated".
-why did the valve float? Because the spring is not controlling the valve motion relative to the cam lobe.
-what are the possible reasons for the spring not controlling the valve motion?
I think this is the real question.
Stiggy has had the springs checked previously and was told they met the specs for the heavy springs using stock valves. Need to confirm that is still the case.
If the valves that RSI put in the head were heavier than the Volvo valves, then, at least the way I'm seeing it, you would need a heavier spring (one with a higher K) to control the valve motion at the max opening transition point. Seat pressure could still be set at the 95 pound target, but a higher K will give you higher spring pressure when the valve is open.
I'm convincing Stiggy to pull an intake and exhaust valve and weigh them.
Does anyone have the weight of the stock valves? Which I believe are what these springs are designed to control in high rev environments.
Admittedly, I'm no Volvo valve train expert, but I do have a 7.0 L engine that spins at the same 6800 - 7000 rpm, and I have spent way too much time on that valve train. I know that for my car, when you go away from the titanium intake valves or the hollow sodium filled exhaust valves to a heavier (more robust?) all stainless valve, that spring rates need to change or the rev limit has to be reduced. Could this be the same thing on his 2.3?
whadda ya tink?
Here's my thinking...
- The lash cap could only be displaced/come lose, if the gap between the valve tip and the inside of the bucket opened up. Otherwise, how would it have ended up not on the valve tip? Stiggy has the numbers, but I think we measured the lash cap at about .080 deep. Would have to look at the geometry, but I'm guessing we'd need around half that to get the lash cap off the valve stem.
- How does the gap open up? By the bucket losing contact with the valve tip at high rpm as the cam sweeps past tip. Essentially the bucket is "thrown" away from the lobe.
- why/how does the bucket lose contact with the cam lobe tip? Because the valve spring is not controlling the valve motion, and at the point where the valve is supposed to change direction (max open) from opening to close, the valve continues to open, the valve gear has now "floated".
-why did the valve float? Because the spring is not controlling the valve motion relative to the cam lobe.
-what are the possible reasons for the spring not controlling the valve motion?
I think this is the real question.
Stiggy has had the springs checked previously and was told they met the specs for the heavy springs using stock valves. Need to confirm that is still the case.
If the valves that RSI put in the head were heavier than the Volvo valves, then, at least the way I'm seeing it, you would need a heavier spring (one with a higher K) to control the valve motion at the max opening transition point. Seat pressure could still be set at the 95 pound target, but a higher K will give you higher spring pressure when the valve is open.
I'm convincing Stiggy to pull an intake and exhaust valve and weigh them.
Does anyone have the weight of the stock valves? Which I believe are what these springs are designed to control in high rev environments.
Admittedly, I'm no Volvo valve train expert, but I do have a 7.0 L engine that spins at the same 6800 - 7000 rpm, and I have spent way too much time on that valve train. I know that for my car, when you go away from the titanium intake valves or the hollow sodium filled exhaust valves to a heavier (more robust?) all stainless valve, that spring rates need to change or the rev limit has to be reduced. Could this be the same thing on his 2.3?
whadda ya tink?
It can also happen with fast ramps on the cam at higher RPMs...especially when bounced off of the limiter. A similar thing happens with cams that have super steep ramps when people try to use them with stock buckets...they kick the shims off of the top of the bucket.
dbarton
Dejected by Volvo Corp.
- Joined
- Nov 17, 2002
- Location
- Prosper, TX
I agree 100% with this. In this case it certainly appears the spring pressure is not strong enough to prevent the cam follower from separating from the lobe surface. And the higher inertia generated by a heavier valve (if that's the case) needs to be overcome by more spring force.
Dave B
Dave B
dbarton
Dejected by Volvo Corp.
- Joined
- Nov 17, 2002
- Location
- Prosper, TX
And not only do the valve weights need to be compared, the combined weight of the stock valve with the stock follower/shim assembly needs to be compared to the new valve and follower assembly that's in there.
mikezohsix
Active member
- Joined
- Jan 6, 2008
- Location
- granville ma
Absolutely agree, the cam profile should be decelerating the valve prior to the valve reversing direction. The RSI cam lobe is very "pointy" compared to the cams I typically deal with, which means they're spending less time decelerating the valve, which in turn means the spring has more momentum from the valve system to overcome. Valve speed is directly proportional to RPM, so high RPM becomes the issue. Force is not proportional to RPM, it's going to be squared. Relatively small changes in RPM are going to have a big effect on force.
Agree 100%, it's the mass of the valve train that is being countered by the spring.
Don't understand where that comes in to play, can you explain?
I'm sure there's a engine builder formula out there that you plug valve speed, valve train mass, RPM, cam profile and who knows what else into and it provides you with a target open spring pressure. Will have to do some digging...
Stiggy Pop
In the cool kids club
- Joined
- Feb 27, 2011
- Location
- Granville, MA
Good conversation, glad I got the right people engaged. This will be a good learning experience for me to take forward.
It looks like this will see me getting pretty involved with the head. If that nets me a reliable and higher quality piece all the better. It's tough considering the money I laid out for the head, but no reason in stressing it at this point.
I've heard the advice on the valves, and it's been on my mind since I first bought it and spoke with Pat.
Looks like the former. The buckets have a raised pedestal which matches the lash caps, no recess for a shim.
We had the buckets as an OD of 1.454", height of 1.023"
The depth of the lash cap lip, pertinent to the float convo, is ~.103"
The lash caps are around .181" in total height with minor variation, so appears the top of the lash caps were machined to get clearance specs.
Spring seats are cut, that ship sailed in 2011 when RSI had the head machined. We're going to try and drop a pair of valves tonight to see what I've got in there.
Re: the cam - as I think we all know the RSI Stage 3 cam isn't a well known quantity. My current thinking is to ask the machine shop to get a real profile off of it. If I have to, I'll move to something different.
My plan is to fix it right, and make the head better than it was new. Whatever that takes, we'll figure it out.
It looks like this will see me getting pretty involved with the head. If that nets me a reliable and higher quality piece all the better. It's tough considering the money I laid out for the head, but no reason in stressing it at this point.
I've heard the advice on the valves, and it's been on my mind since I first bought it and spoke with Pat.
Looks like the former. The buckets have a raised pedestal which matches the lash caps, no recess for a shim.
We had the buckets as an OD of 1.454", height of 1.023"
The depth of the lash cap lip, pertinent to the float convo, is ~.103"
The lash caps are around .181" in total height with minor variation, so appears the top of the lash caps were machined to get clearance specs.
Spring seats are cut, that ship sailed in 2011 when RSI had the head machined. We're going to try and drop a pair of valves tonight to see what I've got in there.
Re: the cam - as I think we all know the RSI Stage 3 cam isn't a well known quantity. My current thinking is to ask the machine shop to get a real profile off of it. If I have to, I'll move to something different.
My plan is to fix it right, and make the head better than it was new. Whatever that takes, we'll figure it out.
dbarton
Dejected by Volvo Corp.
- Joined
- Nov 17, 2002
- Location
- Prosper, TX
Can you tell me the height of the stock bucket without a shim compared to that 1.023" height?
The reason I ask this is I saw the reference to Supertech buckets and I should say something.
Here's the story:
Years ago I put together a big 2-valve head with Ferrea valves and a ton of port work (work was done by Peter Linsson at MVP) and then another person talked me into going the Supertech bucket route with custom top hats. I never got to actually installing that head and later sold it to the guy who talked me into the Supertech buckets. The Supertech buckets I recall were SHORTER than the Volvo buckets, which seemed ok since he was going to run a pretty tall cam. I don't recall the measurements now.
After he got it running the engine shredded the timing belt. He replaced the belt and couldn't find the problem until after it shredded the second belt.
It turned out the problem was the SHORTER buckets in combination with a custom cam that had a slightly shorter baseline. As the buckets came up to the top, there was not enough skirt in the bore to keep them aligned and a bucket jammed and stopped the cam. After the second incident he went back to stock (taller) buckets with a little machined off the bottom and it was fine.
If yours hasn't done THAT, you're probably ok.
Dave B.
Last edited: