1st 212 predator hemi build

[rickyhigbee]

Ok so im doing some mods to my motor that ive never done before. Has a header and stock carb with pod filter and rejetted 140 etube 36 or 37 now. I just ordered billet flywheel(with 8degree timing built in) and rod since the governer has never worked on this since i bought it, and mod 2 cam and 22lbs springs. Is there any special tuning needed with the cam installed. Thanks in advance

 

[CarPlayLB]

When you install the cam, do it with just the crank in, no rod/piston/lifters, put side cover on, and rotate the engine. I am seeing quite a few hemi engines that the crank throw will hit the exhaust lobe of the cam. Just grind the crank counterweight and NOT the cam! You need .030-.050 clearance between the two. This will not affect the balance of the engine at all. make sure your lash is correct at .003. After I adjust the valves, I rotate the engine and check them again. Nothing else "special" is required! Easy install and will make a nice engine!

 

[rickyhigbee]

Ok thanks for the input is there any gains by adding a bored carburetor to this build down the road

 

[rickyhigbee]

Ok i got the parts put on i noticed a few things.
1st the pull start does not engage every time with the billet flywheel is there a spacer i can put between the flywheel and the cup to help this?
2nd it is harder to get started, but idles normal once running and is it common to loose some low end power with these mods?

 

[DeadPixel]

If it were me I would raise compression a lot. Your stock compression is about 8.5:1 which is way low for the cam.

 

[rickyhigbee]

Ok i can get higher compression by using a thinner head gasket right?. I have to tear engine back apart any ways because im getting lots of gas in my oil after get a couple hours run time. Any ideas on what would cause this to happen?

 

[trinik7597]

A lot of fuel in your oil is carb related .. on a stock carb your float is probably sticking or needs adjustment if you are running a pump it could be pushing fuel past the needle valve . Running very rich will cause your motor to be a dog on the bottom end.. I don't know what rod you ordered and I don't know how many times me and ole have said this ... But you can not just throw a thinner gasket on your head !!! You have to check to make sure you have 30 thousands piston to head clearance .. milling or swapping in a smaller cc head is how you add compression as well as trying to achieve zero deck height and using a flat top piston ... There are a few new members here that are offering up advice when they themselves have never built a motor ... At best they would be assemblers not engine builders .

 

[DeadPixel]

I would try to get compression around 10:1 if you could. That would probably require more than a thinner gasket. If you have the room to use a thinner gasket to raise compression though I would do it. Maybe some one else can correct me if I am wrong but I calculated your dynamic compression at around 5.9:1 which is low. Your calculated or whats called your static is 8.5:1 on a stock motor. I would shoot for 7.0-7.5:1. dynamic.

If you had 10:1 static compression it would put you at 6.8: dynamic compression which would be a lot better. I used 82* ABDC from the mod2 cam card to calculate this if any one wants to double check.

Your motor dose not start to build compression tell the intake valve closes and being that you added a lot of duration the cam now closes the intake valve a lot later. You need to raise compression to compensate for this. Raising the compression should give you some of the lost low end back and add power to your mid and upper end.

 

[DeadPixel]

A lot of fuel in your oil is carb related .. on a stock carb your float is probably sticking or needs adjustment if you are running a pump it could be pushing fuel past the needle valve . Running very rich will cause your motor to be a dog on the bottom end.. I don't know what rod you ordered and I don't know how many times me and ole have said this ... But you can not just throw a thinner gasket on your head !!! You have to check to make sure you have 30 thousands piston to head clearance .. milling or swapping in a smaller cc head is how you add compression as well as trying to achieve zero deck height and using a flat top piston ... There are a few new members here that are offering up advice when they themselves have never built a motor ... At best they would be assemblers not engine builders .

Hey trinkit how about when I post something saying it is BS you call out the BS. Never told him to put a thinner head gasket. Been around racing my whole life. Raced mud drags for 3 years and know my way around motors just fine. Might be a noob to lawn mower motors but I build the motor sitting in my 4x4 and had a lot of street strip stuff growing up. I wrote the cam card for the cam sitting in my truck and no that't not the first motor I have built or worked on. Don't take genius to know that 8.5:1 compression is too low for a cam that has 245* duration @0.050. He might have a fuel problem but his motor is going to be a turd dog with that cam in the bottom end know mater what. I have had you say BS a few times but never explain what is BS once...

 

[DeadPixel]

A lot of fuel in your oil is carb related .. on a stock carb your float is probably sticking or needs adjustment if you are running a pump it could be pushing fuel past the needle valve . Running very rich will cause your motor to be a dog on the bottom end.. I don't know what rod you ordered and I don't know how many times me and ole have said this ... But you can not just throw a thinner gasket on your head !!! You have to check to make sure you have 30 thousands piston to head clearance .. milling or swapping in a smaller cc head is how you add compression as well as trying to achieve zero deck height and using a flat top piston ... There are a few new members here that are offering up advice when they themselves have never built a motor ... At best they would be assemblers not engine builders .

Here is the last motor I built trinik. This was before it was dropped in my truck.
This was when it was new and was still being tuned.
You get on my nerves...

https://youtu.be/NWU3ZqmDS08

 

[trinik7597]

The comment was not directed at you specifically !! @ least you are doing the research and asking the questions .. if he has a significant amount of fuel in his oil with a mild build like this there is an issue ... Other than compression

 

[trinik7597]

The mod2 cam is a stock class cam !! It doesn't require increased comp to do what it was designed to

 

[SAS289]

Here is the last motor I built trinik. This was before it was dropped in my truck.
This was when it was new and was still being tuned.
You get on my nerves...

https://youtu.be/NWU3ZqmDS08

Wow. I haven't seen a mid 80's Camaro for years. In the early 90's a guy in one of those wanted to race me from a stop light. I didn't race him but could have probably kept up or beaten him with my mildly built (or should I say "mildly assembled"?) 289 Ford. :smile:

 

[rickyhigbee]

The rod is a std length arc billet rod, and il have to check the carb and see if the float is not closing and its still factory gravity feed not fuel pump

 

[Phil1958]

I would try to get compression around 10:1 if you could. That would probably require more than a thinner gasket. If you have the room to use a thinner gasket to raise compression though I would do it. Maybe some one else can correct me if I am wrong but I calculated your dynamic compression at around 5.9:1 which is low. Your calculated or whats called your static is 8.5:1 on a stock motor. I would shoot for 7.0-7.5:1. dynamic.

If you had 10:1 static compression it would put you at 6.8: dynamic compression which would be a lot better. I used 82* ABDC from the mod2 cam card to calculate this if any one wants to double check.

Your motor dose not start to build compression tell the intake valve closes and being that you added a lot of duration the cam now closes the intake valve a lot later. You need to raise compression to compensate for this. Raising the compression should give you some of the lost low end back and add power to your mid and upper end.

correct me please but to get that low of a dynamic compression the intake valve needs to be open
for ~45 degrees after bottom. how are you calculating this??? 82 degrees after bottom places the piston
at the top minus 98 degrees??!!?? maybe i am missing something here. please explain this.

thanks :thumbsup:

 

[DeadPixel]

correct me please but to get that low of a dynamic compression the intake valve needs to be open
for ~45 degrees after bottom. how are you calculating this??? 82 degrees after bottom places the piston
at the top minus 98 degrees??!!?? maybe i am missing something here. please explain this.

thanks :thumbsup:

Used a compression calculator on line and the cam card for the mod 2 cam. Wallace Racing: Dynamic Compression Ratio Calculator

Got 82 from cam card. The cam is a stock lift cam but its a cheater cam. Its for stock appearing motors and dose not say to raise compression because that is not allowed in the class it is designed for. Dose not mean it dose not require more compression to perform at its best. I have had a lot of friends put large cams in cars with stock compression and it makes the car faster in the mid range and top end but dose not mean the compression is correct.

 

[Phil1958]

Used a compression calculator on line and the cam card for the mod 2 cam. Wallace Racing: Dynamic Compression Ratio Calculator

Got 82 from cam card. The cam is a stock lift cam but its a cheater cam. Its for stock appearing motors and dose not say to raise compression because that is not allowed in the class it is designed for. Dose not mean it dose not require more compression to perform at its best. I have had a lot of friends put large cams in cars with stock compression and it makes the car faster in the mid range and top end but dose not mean the compression is correct.

thanks!

i was lost trying to figure out why would you want a valve open past BDC on a naturally aspirated motor, you
don't! i believe that since the calculator asks for boost pressure it assumes you are running a turbocharger or
supercharger to take advantage of adding pressure past BDC.

 

[trinik7597]

The rod is a std length arc billet rod, and il have to check the carb and see if the float is not closing and its still factory gravity feed not fuel pump

Didn't mean to jack your thread ... The hemi's generally sit about 25 in the hole stock .. but they do vary ... If you went stock legnth on the rod a ten thousands gasket is probably safe . Increasing your comp is a good idea but not necessary with a stock cam . It should still perform well ... How much fuel are we talking about in the crank case ?

 

[super nate]

milling the hemi head takes some thought to, the valve to piston clearance has to be checked!!! depending on cam lift and rocker ratio you can hit a piston on a hemi very easily.