big intake valve

[Typhoon-Dennis]

Hey, i can get L35 with big intake valves.

Problem is: i have a nearly stock engine (only complete MSD ignition, Kenne Belle Intake, fuel regulator)

Which other parts i have to change when i will drive them?

 

[jpalmer]

Re: big intake valve

In reality, none. L35's are a direct swap. Only thing that could be off is your tune.

 

[Typhoon-Dennis]

Re: big intake valve

In reality, none. L35's are a direct swap. Only thing that could be off is your tune.

i mean the big intake valves...

 

[It's just a six]

Re: big intake valve

What size is big? 2.02"?

When you install the 2.02" valves on these stock type heads, they will have a tendancy to crack between the intake & exhaust valves.:2cents:

 

[Typhoon-Dennis]

Re: big intake valve

What size is big? 2.02"?

When you install the 2.02" valves on these stock type heads, they will have a tendancy to crack between the intake & exhaust valves.:2cents:

I can get this heads from a friend, has to ask him which size.
Thanks for that Information, so if they are in this size i wouldn't buy them.

What size would you think is maximum for the L35 and Stock heads?

 

[midnightbluS10]

Re: big intake valve

What size is big? 2.02"?

When you install the 2.02" valves on these stock type heads, they will have a tendancy to crack between the intake & exhaust valves.:2cents:

I thought that was only when you went with the bigger int and exh valves, because it leaves very little material between them.

 

[Windedv6]

Re: big intake valve

Stick when valves no larger than 2.00 to be reliable in L35 or Vortecs, unless they have valve seats like the marine heads do.

John

 

[HopnDude]

Re: big intake valve

^ x2

If you look around and research the Mercruiser Heads/Block they are completely different than the Automotive version. Same mechanic's, but blocks/heads are different aside from the regular moving parts. Boats are ment for long periods at WOT, not cars; thus needing something with higher tolerances.

 

[wildphil]

Re: big intake valve

Stick when valves no larger than 2.00 to be reliable in L35 or Vortecs, unless they have valve seats like the marine heads do.

John

How are the valve seats in the marine heads different?

 

[It's just a six]

Re: big intake valve

What size would you think is maximum for the L35 and Stock heads?

Generally, I would not go any larger than a 2.0" intake & 1.60" exhaust to be safer than a 2.02" 1.60" ex, that leaves little material between the valves.

If you are going for an all out race type porting, larger valves etc, then sure, but reliability will not be good, the head castings do not have much material to remove before you port into a water jacket.

If you are going to install larger intake valves to increase the flow, you should install 1.60" exhaust to improve the exhaust flow also.

I never heard of anyone just installing a 2.02" intake valve & stock sized exhaust valve, you would show a gain but not as much if you increased both valves.:2cents:

 

[Typhoon-Dennis]

If you are going to install larger intake valves to increase the flow, you should install 1.60" exhaust to improve the exhaust flow also.

I never heard of anyone just installing a 2.02" intake valve & stock sized exhaust valve, you would show a gain but not as much if you increased both valves.:2cents:

Thats something i'm also thinking about.
So i have to Proof if there are larger exhaust valves...

 

[Davemc1963]

Re: big intake valve

^ x2

If you look around and research the Mercruiser Heads/Block they are completely different than the Automotive version. Same mechanic's, but blocks/heads are different aside from the regular moving parts. Boats are ment for long periods at WOT, not cars; thus needing something with higher tolerances.

Does this mean Mercruiser 'L35' type heads are an upgrade to the regular 'car type' heads then? Are they a straight swap? and if so, what are the casting numbers to look for? I know these have been mentioned before, but I cant remember any conclusive or compelling reasons to hunt them out. I think they have screw in studs from what I have read. I know you can get Mercruiser Vortecs as well. Anyone using either of them over regular 'car types' ?