new build, starter cant turn against compression

[ravivos]

Hi,
So i've finished assembling a new T3 engine,
2021cc (76X92)
CB044 heads
CR 9.1:1
1.25 rockers on a Norris 336s cam

The starter turns the engine nice an easy when the spark plugs are removed.
once the spark plugs are been reinstalled, the starter cant turn the engine due to compression.
if i try rotating the crank by hand (using a wrench), i can turn it without it been mechanically locked... although rather difficult to turn .
valve lash is set correctly.
no fuel in carbs so its not a hydraulic lock.

any ideas on how to address this subject?
Thanks
Ravivos.

[Quokka42]

Check your earthing and battery. A stock starter should be able to turn that engine. Many pros use a truck battery or second battery in parallel when starting new engines.
_________________
There has only ever been one man who was perfect, and they nailed Him to a cross.

[raul arrese]

If your starter is good then you need a better battery with more cold cranking amps , and also make sure your cables are good ... I always over kill my cable sizes .

[[email protected]]

[mcmscott]

If your starter, battery, cables and everything associated are good, then that motor is building way too much cylinder pressure. If it runs it will detonate itself to death. Have you calculated dynamic compression? Not static.
_________________
There are no stupid questions, only stupid people,

68 Ghia
67 T-1
65 Notch
02 Mexican beetle
74 Thing
15 Long travel rail
07 Nomad
05 f-250

[ravivos]

Well,
this is a first start on a test stand that i build.
cables are good, battery is new, but i suspect the the starter is shot, got it in a swap and i was skeptic about it from the beginning.

will try taking the starter off my transmission and bolt it to my test stand.
further investigation shows that the copper/bronze starter shaft bushing is too thin, so perhaps the starter gets into a bind when loading it.

as for dynamic compression ratio, i've calculated it to 6.8:1, so i guess thats not the problem.

Will go over the entire starter assembly to make sure it is straight and true.

Thanks.

[mark tucker]

make sure the cam is degreed corectly too. and that the sparking bolts are not contacting the piston.(kinda hard to do with the cr you have&the heads you have. make sure there is greessee on the starter bushing,I also like some antiseezzee on the ringear&starter gear.be sure you have the oil system full&working, compression agnist a dry bearing wont work.I also use a thin oil for breakin....well I use thin oil all the time in my stuff.

[esde]

Will it turn he engine over if you have the coil unplugged? If so check your firing order and ignition timing..

[Dale M.]

IF you are going to replace (in future) the dedicated starter on engine stand, get starter for auto-trans (SR 17) they have a little more muscle to turn over motor and do not require any bushing in bell housing as they are self supported...

Dale
_________________
“Fear The Government That Wants To Take Your Guns" - Thomas Jefferson.

"Kellison Sand Piper Roadster" For Street & Show.
"Joe Pody Sandrover" Buggy with 2180 for Autocross (Sold)
============================================================
All suggestions and advice are purely my own opinion. You are free to ignore them if you wish ...

[stevecul8er]

I encountered a similar problem with my rigged engine stand and thought the compression was the problem, then starter, and battery. With plugs removed the engine would over real freely-once spark plugs back in it wouldn't turn over. I even tried to jump start with no results.
MY solution was to make sure all electrical connections and cable and wire sizes are large enough to carry the electrical current to the starter.

[Danwvw]

Last time I test started and engine that way using jumper cables, I had to try 3 starters before I found one that was good enough to crank it over. Those Automatic Transmission starters are much stronger. SR17.
_________________
1960 Beetle And 1679cc DP W-100 & Dual Zeniths!

[ravivos]

after going through 2 starters that didnt turned the engine, i took the starter off of my transmission and mounted it onto my engine stand.
instantly, i could see it is much better.
but then i realized that the main problem was that the starter wasn't aligned with the designated drill for the bushing, and all of these weren't aligned with the correct position for the flywheel.
it seems that the entire starter mounting plate got distorted, probably when i welded it.

eventually, manage to find the correct position for the crank and bushing, so now the starter turns the engine with a nice authority (not as much as i wanted, but it will be enough).
the only problem is that now after all these attempts, the battery is drained, so starting the engine will have to wait another day or two.

i have to get me a different starter, the one with the self bushing sounds fantastic and will be perfect for my stand.
will look for one.... thanks.

so. engine gets cranking, oil pressure increased, but it seems i am unable to properly prime the fuel pump (mechanic)... any recommendations on that?

Thanks

[Danwvw]

The mechanical fuel pumps should self prime if you hold the gas your using for gas up above the pump (crank a little) then they are ok, once primed the gas can be several feet below and they will pull it fine.
_________________
1960 Beetle And 1679cc DP W-100 & Dual Zeniths!

[jfats808]

As mentioned check ground. Then recheck static timing. Prime fuel, sometimes opening and closing the throttle a lil helps it along. Finally, hooking up a starter charger helps a low cca battery. Someone can come along and verify the part number in that bosch starter. I think its something like and sr71 or sr something..
_________________
2276 IDA's 86C 11-1 DD !
2017 48 Trijet DRLA's W125

[Dale M.]

[Dale M.]

[Bajaman65]

I bought a pre-made engine run stand online and it is very nice except for the starter bracket. It will not handle the torque from an SR 17 without bending and the gears climb on top of each other. It came with a mount for a bushing type starter and now I know why. I only build big engines and was worried about cranking, turns out that a stock starter can crank over a 2387 wit 9.5cr with no problem. I still run the High Torque Starters in my cars but they are very solid on the tran's.
One thing to be careful of is if your timing is to advanced it will make the engine kick back hard on the starter.

[ravivos]

o.k.
so i took the fuel pump apart, cleaned it and now it works fine, the carbs are full and the accelerator pump works good an all four carbs, they are the HPMX 40 with 32 vents.

set my static timing (cyl. no 1 fires) at approx 7-10 degs.

here are some pictures of the stand, it is fantastic to build engines on, and i add another leg to support the engine for starting and running on the stand.

spent too much time fiddling with this thing, will just get me the SR-71 and be done with it...

Yes, i know... i have a total mess in my shed...
it happens when you restoring 2 cars and 1 bike in parallel...
maybe one day ill have a bigger place for all this stuff...

in the photos you can see my T3 engine, i've built a custom exhaust system for it (Stainless) and the muffler.
the engine will have an air conditioner.
already have the MegaJolt in a box waiting for me to mess with it.

[jfats808]

Kick ass job on the exhaust brutha. Make sure u get adequate venting/fan in there on start up.
_________________
2276 IDA's 86C 11-1 DD !
2017 48 Trijet DRLA's W125

[Dale M.]

Its SR 17... SR 17X if reman....

f it were my engine stand I would drop motor down lower to ground and add 002 bus bell housing....

Dale
_________________
“Fear The Government That Wants To Take Your Guns" - Thomas Jefferson.

"Kellison Sand Piper Roadster" For Street & Show.
"Joe Pody Sandrover" Buggy with 2180 for Autocross (Sold)
============================================================
All suggestions and advice are purely my own opinion. You are free to ignore them if you wish ...