1.7 Rebuild First Start Up Advice, 1.7 Start Up on stand Options

[Superhawk996]

It looks like a ton of work for a little old 4, tell you what, why don't I just take that off your hands? I have a old bus engine fully assembled that I could give you instead.

Oh. . . So now you want to build a motor. (IMG:style_emoticons/default/poke.gif) (IMG:style_emoticons/default/biggrin.gif)

[emerygt350]

It looks like a ton of work for a little old 4, tell you what, why don't I just take that off your hands? I have a old bus engine fully assembled that I could give you instead.

Oh. . . So now you want to build a motor. (IMG:style_emoticons/default/poke.gif) (IMG:style_emoticons/default/biggrin.gif)

Well, I think I would be doing a guy a favor! (IMG:style_emoticons/default/wink.gif)

[technicalninja]

Support mods that I think are important for this level of motor.

Big exhaust! You have DOUBLED the heat output; you need a serious exhaust to not "back up the sewer" with heat.
Raby himself suggests 4 into one with short collectors for his stuff.

@Literati914 has a nice set of short collector 4/1 set up that I'm hoping he will post a pic of.

Then there's the Tangerine stuff...
https://tangerineracing.com/shop/ols/produc...eet-system-1-58

His systems are what is referred to as tri-y and have two distinct collectors 2-1 than 2-1 again. There are good reasons to do it this way. You end up with two negative pulses at the exhaust port exit this way at different rpm ranges.

Pricy but very nice! I'd go Tangerine is cost wasn't an object.
That used set up was a good deal!

There is a BUNCH of good stuff out there! You CAN use the normal SSI heat exchangers, but they will be a bottleneck at high flow rates.


Because of doubling the heat output, you also need good temperature tracking.

Oil temp is important. Don't trust the original gauges. An accurate temp gauge is a requirement long before ANY oil cooler is warranted. You MIGHT need the cooler as well; the gauge will let you know if you do.

More important is cylinder head temp. Best to have sensor around #3 spark plug.
Lots of threads on here, many different was to go. I actually bought a 4-channel gauge from a member on here as I'm prone to gather WAY MORE data than I really need.

Then there is wide band O2 sensors. If you're not using these, you are back in the stone age of reading plugs for tuning data. Wideband is PARAMOUNT in any build IMO.

Oil mods, your oil pump can be a weak point. I'm an absolute bitch about "sucking air" which is possible with a stock oil pump. Pumps are made with dedicated O-rings that stop that shit. Lots of threads about pumps as well.

Then there's the oil pick up. A "tuna can" is the minimum IMO. Lots of threads again...

Fuel supply, you need to be able to deliver at least 200hp worth of fuel at all times.
At this level of engine, I'd be running a 7-8psi pump under the tank and a fuel pressure regulator to reduce this to 3 psi right before the carbs.
Overkill, but if you run lean EVER it will GO BANG and you will be sad.

Ignition: No points for this, modern electronic distributor. Many are available but the current "King of the hill" is the 123 blue tooth model.

I'm actually a fan of full-on stand-alone modern EFI with sequential injection and sequential coil on plug but you already have the proper sized carbs, and this jump is every bit as big a jump as the 1.7 to 2.255 jump you lucked into.

Even I would fire what you have on carbs first.

Talking about that...
I'm using the lowest of the low induction system for initial run in/cam bedding.
My 75 came with a brand new progressive 2bb. This is a single carb in the center over a plenum that feeds all 4 cylinders. This thing is SUCK CITY for performance but it is beyond easy for initial set up.
I'd use the baby single Weber to get the engine through the first CRITICAL run in period. I'd bed the cam and make sure the thing is proper before trying to add ITBs.
The ITBs can have initial teething issues and I don't want to be jacking around with that type of shit while the cam is bedding in.
Baby Weber for an hour and then the REAL carbs...

You shouldn't have to purchase this puppy, lots of us have one and most would be willing to let you use them for a short period of time as the ONLY time we use them is for run in as I have just described.
They REALLY do SUCK but they are drop dead easy to make work!

Enough for now...

[emerygt350]

I have an old progressive solex in the basement. The opel gt community had shot put contests with them back in the 80s....

[Robroe]

On balancing...

Pistons/rods I will balance to +/- 0.5 grams

But the entire assembly I will accept +/- 2 grams.

Doesn't have to be super close!

When an engine runs it ends up with oil entrained on all of the parts and this oil "ropes" differently on different parts.

Due to the amount of oil hanging on the parts the engine will NEVER be in "perfect balance".
It CANNOT happen unless you get rid of the oil!

Dry sump has less of this happening but it's still significant.

When someone tells me the entire assembly is +/- some tiny amount it just means that they don't understand what is happening inside an engine while it's running...

When a good machine shop calculates "bob weights" for a V engine they should ALWAYS include 5 grams for this entrained oil in each bob weight.

Head porting photos. Just ordered AA 2 arm bench mount yoke. Looks pretty solid but will weld additional material if it looks questionable.

Facet fuel pump mounted under fuel tank in Frunk and Exhaust. 2.0 stainless heat exchangers

[Robroe]

On balancing...

Pistons/rods I will balance to +/- 0.5 grams

But the entire assembly I will accept +/- 2 grams.

Doesn't have to be super close!

When an engine runs it ends up with oil entrained on all of the parts and this oil "ropes" differently on different parts.

Due to the amount of oil hanging on the parts the engine will NEVER be in "perfect balance".
It CANNOT happen unless you get rid of the oil!

Dry sump has less of this happening but it's still significant.

When someone tells me the entire assembly is +/- some tiny amount it just means that they don't understand what is happening inside an engine while it's running...

When a good machine shop calculates "bob weights" for a V engine they should ALWAYS include 5 grams for this entrained oil in each bob weight.

Head porting photos. Just ordered AA 2 arm bench mount yoke. Looks pretty solid but will weld additional material if it looks questionable.

Facet fuel pump mounted under fuel tank in Frunk and Exhaust. 2.0 stainless heat exchangers

Cylinder shims. Trying to use just one instead of the 4 stacked that the engine builder used. The shims added up to .150”. Closest single shim I can find is .160” from type 4 store. This will add .010” to my deck height bringing it from .052” to .062”. This brings compression to just around 8.0. Rim o used to do custom shim thickness but looks like they are out of business. Any sources for shims at .150”?

This will be a fun weekend car and probably not going to the track.

[Superhawk996]

Food for thought:

Shims - call Type 4 store / LN Engineering about what shim you need made. Shims are Blanchard ground for precise thickness and uniformity. A 0.160” shim can be ground down to exactly what you want. If Type 4 store can’t do it, find a local machine shop with a Blanchard Grinder and have it done there.

Stroker with cast iron cylinders and higher compression ratio is going to generate more heat - what is the plan to keep the engine cool? Is this engine set up for external oil cooler?

What oil pump is being used? Be aware that if a Type 1 oil pump has been substituted, you need to carefully measure the pump OD vs the engine case pump bore ID. Type 1 pumps are often grossly undersized allowing internal oil pressure leakage between pump outlet and case inlet. Likewise this can lead to sucking in air into the oil. Both of these will lead to low oil pressure especially when the engine is hot. Finally, Type 1 oil pump inlet / outlet location are slightly misaligned to the type 4 case - may need some custom port alignment to get things matched up properly.

Was the case machined with the Raby style rear main seal drainback to help reduce RMS leaks? Probably want to look into that while engine is apart.

Stock or SSI heat exchanger is going to limit your HP as Ninja already pointed out. Inability to quickly & efficiently move hot exhaust gasses out of the engine will lead to increased engine temperature as well.

[Jack Standz]

Pretty sure the Type IV Store can make you some custom spacers for your cylinders. It just takes a little longer.

You can get an o-ringed type 1 pump from Gene Berg Enterprises in normal or full flow versions with either 26mm or 30mm gears.

[technicalninja]

On balancing...

Pistons/rods I will balance to +/- 0.5 grams

But the entire assembly I will accept +/- 2 grams.

Doesn't have to be super close!

When an engine runs it ends up with oil entrained on all of the parts and this oil "ropes" differently on different parts.

Due to the amount of oil hanging on the parts the engine will NEVER be in "perfect balance".
It CANNOT happen unless you get rid of the oil!

Dry sump has less of this happening but it's still significant.

When someone tells me the entire assembly is +/- some tiny amount it just means that they don't understand what is happening inside an engine while it's running...

When a good machine shop calculates "bob weights" for a V engine they should ALWAYS include 5 grams for this entrained oil in each bob weight.

Head porting photos. Just ordered AA 2 arm bench mount yoke. Looks pretty solid but will weld additional material if it looks questionable.

Facet fuel pump mounted under fuel tank in Frunk and Exhaust. 2.0 stainless heat exchangers

Cylinder shims. Trying to use just one instead of the 4 stacked that the engine builder used. The shims added up to .150”. Closest single shim I can find is .160” from type 4 store. This will add .010” to my deck height bringing it from .052” to .062”. This brings compression to just around 8.0. Rim o used to do custom shim thickness but looks like they are out of business. Any sources for shims at .150”?

This will be a fun weekend car and probably not going to the track.

Better check your math...

Flat top 2255s run 9+ on compression ratio. I bet you forgot to add the 1

You'll be at 9 not 8

Swept volume divided by clearance volume + 1

Or (swept volume+ clearance volume) divided by clearance volume.

Both equal same numbers...

2255 strokers are usually ABOVE 9.0-1

I LIKE it there! I'd be hunting 9.5-1 but I'd also be doing full on EFI and running E/85 which most of the members on here would "Burn me at the stake" for.
(IMG:style_emoticons/default/ninja.gif)