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Calling Cooter

899 views 14 replies 3 participants last post by  crazycooter 
G
#1 ·
Cooter, wasn't it you who said that the older and newer 1300 zooks have different ratio rocker arms?
What was the outcome of your testing?
Is it worth the effort do you think?
TIA
Alfie.
 
#3 ·
As far as I know , all Samurai 1324cc engines used the same rocker ratio of 1.6 from '86 - '95 . Now , as far as the worldwide market , who knows ? You can check yours to make sure with a dial indicator and a few minutes of time . Measure the actual lift at the valve and divide that amount by the lobe height of lift on the cam , that is the ratio ....
Sarge
 
#4 ·
I took all my stuff to a local place called "Rocker Arm Specialists" to get it checked out.

My 92 Zuk came with 1.3 ratio arms.

MY 88, 89, and all other early Zuks I have worked on, have had 1.45 ratio arms.

From what I havce found, the EFI cam has taller lobes and smaller arms. The carbed cam has smaller lobes and larger arms. The difference is obvious when put next to each other.

I put the larger arms on the larger EFI cam. Now I have a good idling engine that passes smog and kicks butt! Just check for clearance on the valve springs.

This netted me .375" lift @ the valve.

For the guys who are running regrinds, those cams have a smaller base circle. This changes where the wear pad on the rocker arm the the cam lobe meet....reducing the arm's effective ratio.

I don't know if the arms on my Zuk were changed? I bought it in 97 with 58,000 miles on it, so I could only assume it was stock.

Hope this help someone.
 
#5 ·
Good info , I totally forgot about the difference in the EFI models . All the rockers I've had are 1.6 ratio , even the new replacement ones from Suzuki . And yes , any regrind removes some of the base diameter and effectively changes the ratio a bit . This is why I won't run regrinds just new billet units with the correct base diameter .
Sarge
 
G
#6 ·
Thanks Cooter and Sarge. I don't understand Base circle, but it sounds important.
We never received the EFI model here. Only the carbed 1324, and then the carbed 1298, which is what I have.

If I can deduce correctly here, it sounds like a new billet cam and some 1324 rockers would be an advantage?
Some engineers blue and a file on the headers and inlet manifold too ?

Sorry if I sound dumb, but I am.
TIA
Alfie.
 
#7 ·
I'll try to post some pictures to help indentify the two.

Been slammed at the shop, so it may be a few days.

I was also working on roller rockers. I could not find anything off the shelf that would work, so they would have to be custom. Since most of these guys won't spent that kind of money, it would cost way too much money for just a few sets.
 
G
#8 ·
Thanks Cooter, I'd appreciate that.
Yeah, I know what you mean about Zookers, tight as I reckon.
I'm thinking I might go for a 272 grind (New billet) cam and try to source the 1324 arms.
My motor is an interference motor anyway, so a heap of lift won't matter at all.

TIA
Alf.
 
#13 ·
cooter, that is some great tech you have provided. thanks.

if i am following this correctly, for an efi zuk you can simply install the old larger style rockers and get more lift?

so if you have an older carbed zuk, would you get the same gain by running an efi cam with the old larger rockers?
 
#15 ·
Yep, that's right.

I have found the best performance with the EFI cam and early rockers.

I have enough bottom-end torque to bust a Dodge motor mount every couple months!

A new shop in town put in a dyno. I want to get some real numbers.

The local dragstrip just opened too.
 
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