OST-070: 7AGE for an N2 Levin

[banpei]

I think that's a good question. There is an issue with the 4AGE in transverse configuration where you get an oil surge on long right turns. That's why there are baffles available to stop the oil from being pushed in the wrong direction causing oil starvation at the pickup.
Can the same thing happen on a longitudinal installed engines?

[oldeskewltoy]

(08-15-2020 10:49 PM)Vaptor Wrote:  What is the advantage of the MRP's wet sump, compared to a normal AE86 sump?

3 distinct advantages: 1) Volume... the MRP pan holds 5 quarts, the largest stock pan holds 4, and some 4AG pans holds only 3.5. 2) built in windage tray as well as baffles/trap doors to keep oil around the pick up. 3) extra bungs built in.

The most important of these, without a doubt, is the extra quart of oil.




cleaned and prepped, and epoxied... note oil pan and oil pump have previously seen duty as painting fill ins




now the block waits 3 weeks for the coating to fully cure.





also re-did the crank pulley




more to come.......

[oldeskewltoy]

from another forum Wrote:Epoxy instead of paint?

Have you heard of ceramic coating a block, for shedding heat? I was talking to someone at a shop who has ceramic coated parts for me, was getting some ideas. I was thinking about ceramic coating the 4A block that I've been using as a guinea pig (smoothing out the inside casting, etc).

same product that I used on OST-050. It is far thinner than paint, and yet once cured far more durable. The look also replicates the original block when new.





I have heard of ceramic coatings on all kinds of engine parts. Typically the 4/7 A blocks don't usually have cooling issues. I have looked into other coatings as well, but this is the most cost effective for what I'm trying to deliver.


more to come...

[oldeskewltoy]

(08-13-2020 08:48 PM)oldeskewltoy Wrote:  

(08-11-2020 09:48 PM)Vaptor Wrote:  Looking forward to this build, please post as many details as possible, also about the block assembly, would be nice to have a good build tread about a 7AGE, as I am going to build one for my car

Will you be using a 4AGE Oil pump?

yes... with a few minor modifications (more later)

and now its later....

The OEM oil pump will have a number of modifications to help this mild mannered beast stay lubricated. As I've done before, this pump got mildly ported, smoothing the transition at the entrance to the pump(3), tapering the exit from the pump body(2), and gently working the inner radius of the pumps exit(1).

(photo from OST-053)

I also installed the SQ pressure relief valve spring kit (Australia)




Along with all of those mods, this pump also need one or 2 more......



The 7A block, being taller, has the oil galley slightly further out then the 4A. The 7A pump matches the outlet, but has a few "flaws", the pump gears are not as thick, (so they can't use Toda pump gears) and it fits the "wrong" lower timing cover.

The 4AG pump has a flaw as well....(when using with a 7A block), the outlet isn't in the correct location.


So beginning with a 4AG pump I added 2 more radii, one inner(on the block), and one outer( on the pump) to remedy that




more to come.....

[Vaptor]

Prepared my own Oil pump, with port matched it with the Block, and did Pos 2 and 3, also got the SQ Spring, but pos 1 I did not do.

As I understand it, you have rounded the inner rough edge, to get a smother rounding. Correct?

[oldeskewltoy]

(08-19-2020 08:54 PM)Vaptor Wrote:  Prepared my own Oil pump, with port matched it with the Block, and did Pos 2 and 3, also got the SQ Spring, but pos 1 I did not do.

As I understand it, you have rounded the inner rough edge, to get a smother rounding. Correct?

removing machining marks, and providing a "softer" radius at the entrance.



The head gets a deburr....

intake side...





and the exhaust side




more to come...

[oldeskewltoy]

Oh... and of course... big valves need big seats




more to come....

[oldeskewltoy]

So... after about 6 hours working #1 - all on the intake side.... I decided to do a casting for comparison










more to come.....

[oldeskewltoy]

... and an exhaust port capable of much greater flow........




more to come....

[Vaptor]

The Exhaust gasket you are using here, what specific model is it, and from what company?