How difficult is it to change the valvesprings with the head on the car. I've done valvesprings before on a Chevy V8 on the car. Is it similar? Can you use one of these?


If that sort of tool doesn't work, what do you need to change them on the car. Thanks.

 

...you would also need the air fitting to pressurize the combustion chamber to keep from "dropping the valve".

 

OK.... again - lets show everyone how we quantify the contact.

First we measure the length of exposed valvestem from the valveseal to the tip with valve in closed position (as shown below) 24.42mm


then we subtract the length from tip to the bottom of the retainer 14.27mm



what we are left with is 10.15mm of useable valve travel before the retainer will contact the seal.

for reference........ HKS cams have how much valvelift?
so yes all HKS cams run without a spring and retainer upgrade will see interference between the OEM retainers and the valvestem seals.

Jason, Beau and the whole Revolver team

 

that one doesnt work for the EVO

this is the one we use click me

nice and easy - with plenty of room for tweezers and magnets (for the keepers)

 

ogvw,

for all the calculations .. seems like your measurements also doesn't stand for stock cams .. since at 10mm lift with a rocker ratio > 1:1 .. it stands to reason that stock cams will also exceed 10.15mm (your measurements)..

Care to comment on this ??

 

ogvw,

Nice to see you and I can have an intelligent conversation here.

I see how you measured it, which is basically what I outlined above. Difference was we measure the tip to seal and then pulled the valve and marked the stem. Then installed the retainer/keepers and measured the difference. We came up with .471 and you come up with .399. As we all know that isn't even enough for the stock cams to work as stock lift is .393 plus the rocker arm ratio which easily will take it over .400. In your theory you are telling us that Mitsubishi themselves are assembling and building these heads with a retainer to seal contact problem. I don't believe that. Something else is wrong with the head you are taking measurements on.

Looking at the picture you posted the valve itself does not look like it has ever been machined properly. Has anyone there checked the installed height of the valve? There is a spec for the spring seat to valve tip height, if your valve stem hasn't been machined on the tip end yet for installed height this could throw off what you are trying to do. Most of the heads that come through here from other shops have never had this done and it is critical. it is something we do on every single head that is done here.

The .072 difference in what you are measuring and what we are measuring is the problem and we are both measuring the same way basically. We just need to find what the difference is.

As you all know I will admit it if I am wrong and I am not liar. I don't believe ogvw is a liar either, as he is showing proof of what they are saying. Something is up with the head/valve though as there is no way Mitsu is putting these heads together from the factory with a clearance problem, agreed?

David Buschur
www.buschurracing.com

 

All the measurements I have givin are AT THE VALVE. The only time you need to do the rocker arm ratio calculations are when you are trying to figure out "valve lift" by measuring from the camshaft. FWIW the OEM rockerarms have a 1.7 to 1 ratio.

 

We measured tip to seal....then subtracted the distance from tip to bottom of the retainer (I measured this on 7 or 8 different valves - all the same dimensions were found) Are you sure that you are measuring a stock EVO retainer?



The stock cam has 10mm intake (.393") and 9.5mm exhaust (.374") lift AT THE VALVE!!!

to figure out the actual lift on the cam you DIVIDE valve lift by 1.7..... giving you 5.88 mm for the actual lift on the cam. Go ahead, try it - first measure the base cirsle of the cam (smallest OD) then measure from the tip of the "nose" on the cam to the bottom of the "heel" - subtract these two numbers and that gives you the cam lift, multiply these by 1.7 and that gives you lift at the valve. It is quite simple really.....


Do the math David - there is nothing wrong woth the heads as sends them out. As I have said before this head is completely stock and low mileage. I have tested and measured at least 5 different heads off the car and many many more on the car - ALL WERE THE SAME.


This head came off of a running car........ making about 300+whp (no internal mods)

CORRECT!! Mitsubishi does not put these together with a clearance problem.... stock lift at the valve is 10mm/9.5mm and the contact only happens at 10.15

David please understand that this has nothing to do with you or your shop, hell even HKS says its ok. The simple fact is that they must have neglected to check for it. We do this for a living, so we HAVE to make SURE that there will be no problems by checking and double checking our measurements as I have proven by taking pictures of the whole process. Please feel free to PM or call me with any questions - Id love to get you guys on board with some of our products.

Jason

 

A bit off topic, but Jason, do you guys sell the springs/retainers separatly or only as a package with your cams?

Thanks,
Terry S

 

We sell them seperately also......

I believe ZEUS is organizing a discount purchase, PM him for details

Thanks

Jason

 

Maybe I am misunderstanding here, but I believe from OGVW's posts, he is saying that a factory head is fine UNTIL you add cams. Once cams are added then there is an issue with the contact.

Am I off base?


PS---We just wrapped up our HKS 264/272 cam install on a client's EVO, also using Revolver's springs and steel retainers(sent to us via next day air because of the information Revolver has brought forth in this post). Everything installed like a gem(first time we've done springs in an EVO but it was cake). Now our client is glad he waited the extra day for the Revolver goods--no headaches for down the road.

 

So you can use the revolver springs & retainers in combination with the HKS Cams?? This is good. What does a set of spring/retainers go for? i did not see it on your site

 

Our new site is making it's way up this month.

Here is pricing;

Revolver high rev single spring set(set of 16) and steel retainers for EVO8;
$249

LMK if I can help at all.
Best,
Jeremy

 

You are correct about lift at the valve, I realized it after I typed the above paragraph and called the machine shop to verify. The intake valve on the HKS cams is the higher of the two lifts and measures .424 lift, at the valve.

Regardless, we came up with .471 from the bottom of the stock retainer to the top of the seal.


Not sure what the differences are or why we are coming up with two different things.....

David Buschur
www.buschurracing.com

 

I'll just say for now that the first 10 people in the group buy will get the spring/retainer set for less shipped than anyone is advertising their pricing at now(PM for details)... This group buy will bring me no profit at all as I'm just organizing it for us, the members... not as a vendor.

I'm still waiting for my vendor packet from Mark before I will attempt to make any money.