54 replies to this topic

[hotwheels]

Specs
A+ 1275 +60 freshly bored and running mini spares flat top pistons

286 kent cam and double springs with 4 degree offset key 105.5 degrees

Not sure what type of head

Single HIF 6 1.75 carb with bbc needle



Issue is after first start up and about 10 mins later, started getting smoke out the tail pipe. There is oil resido in cylinders 2 and 3 and a little bit in 1

I was tryin to set the static initial timing between 6-8 and thats when it started smoking, also it was running rich. Still having trouble setting the carb

My main concern is the oil im finding. Any ideas

Should i rip the head off and check the valves?

[Dusky]

Id check your cr ratio. Flat tops in a 1275 +60??

[blacktulip]

Did you stagger the ring gaps? Also would like to know what cr you are running as you would need a lot of chamber enlarging if using a normal 12g940 casting.

[hotwheels]

The machine shop are the ones who installed the main crank, conrods, and fitted the pistons to the block. So i figured they new what they were doing because thats all they specialize in. Compression ratio i believe is 10.1

Right now i dont know what castin it is but i would assume its the normal one.

What do you mean by chamber enlarging?

Thanks for the reply

[hotwheels]

The machine shop are the ones who installed the main crank, conrods, and fitted the pistons to the block. So i figured they new what they were doing because thats all they specialize in. Compression ratio i believe is 10.1

Right now i dont know what castin it is but i would assume its the normal one.

What do you mean by chamber enlarging?

Thanks for the reply

[hotwheels]

https://www.minispar...|Back to search These are the pistons i got

[dyshipfakta]

Worth taking the head off to check valves and check your comp ratio. Hopefully just valve stem if you didn't do anything to the head or don't know it's condition.

[Spider]

Have you had any load on it at all yet, or just idling / running in the garage?

[hotwheels]

i did not mention but the machine shop put new valve guide and seals in also, i have not put any load on it yet and i was still trying to adjust the carb and static timing

[Spider]

 i have not put any load on it yet

 

The advice I give when I build an engine for someone else is to NOT run it at all UNTIL it can get load on it RIGHT away. Not even run it for 1 minute.

 

With my own cars, I position them such that even before I get my hand off the key, I'm driving it right away, I doubt that they'd have 1/2 a second of unloaded run time.

 

Without load very very early on, the bores glaze very easily and then a hone is needed again to remove the glazing.

 

Once glazed, they will always smoke and never break in.

 

I'll stress, that this is the advice I give for engines I've built.

[absx2]

I totally agree with Moke Spider as I was told years ago to run them in how you want them to go and I have had no problems since cocking up my first rebuilt motorcycle engine about 30 years ago by not using the revs.

There are many discussions on the web about running motors in and the main theory is that the rings need to be forced against the bores to avoid glazing. This can be done immediately on a fresh build by brief acceleration followed by overrun. If using a new cam and followers you should run the motor at 2-2500 rpm for 20 minutes or so to break the cam in then take it down the road using short bursts of 70% load.  Anyway its worked for dozens of my motors, mainly motorcycles with a few crossflows and A series.

The pistons on a briskly run in motor show no signs of blow by but an unloaded motors pistons are black.

I worked in a dealership a few years back and was initially horrified at the abuse the brand new motors would get in the hands of staff especially when collecting a vehicle from another dealership as it was more of a drag meet than a car collection. 

Funny old thing is the courtesy car was always the fastest and more economical due to its hard life from day one.  

Enough said. 

Edited by absx2, 19 June 2016 - 09:21 AM.

[hotwheels]

Quick question took the valve cover off. Notice intake valves has stem seal but exhaust vakves did not. Should they have?? Idk the machine shop did this.

[cal844]

General recommendations is to fit valve stem seals to all valves

[blacktulip]

 i have not put any load on it yet

 
The advice I give when I build an engine for someone else is to NOT run it at all UNTIL it can get load on it RIGHT away. Not even run it for 1 minute.
 
With my own cars, I position them such that even before I get my hand off the key, I'm driving it right away, I doubt that they'd have 1/2 a second of unloaded run time.
 
Without load very very early on, the bores glaze very easily and then a hone is needed again to remove the glazing.
 
Once glazed, they will always smoke and never break in.
 
I'll stress, that this is the advice I give for engines I've built.

I'm glad I read this, I'm just about to run a fresh engine build in. Can I ask how would you set up the engine so it's ready to go right away if the engine is modified? Sorry to hijack.

[hotwheels]

i ordered all new guides and seals and bringing it back to the machine shop, they did not now the exhaust valves needed stem seals, so after all this is done hopefully it will fix my oil problem, 

 

also what would be a good break in oil to use?