4age Block suitability

[306rwd]

I have just bought a low mileage second hand 4age to use as a basis for my competition engine build. It is a small port head, 7 rib block, no TVIS engine from a 1990 UK Corolla.

the difference between this engine and my previous competion motor is that this block has the oil squirters whereas my previous 7 rib block (the one with the big con rod hole in the side) did not have the squirters.

My question is if this block with the squirters is suitable, better, worse that the one without for a N/A engine revingto 8500 with about 185bhp? Or is there no difference?

The new engine will be running a dry sump system so volume of oil should not be a problem.

Thanks

[skiddz]

i was under the impression the oilsquirters made a difference, in keeping the piston skirt cooler, i dont really see how it could be detrimental to have oil squirters

[30psi 4agte]

It will be the same if not better. like skids said aids in keeping the piston skirts cool. This is not such a major think on a n/a motor but is very useful when forced induction is involved.

Im curious as to how you managed to throw a leg out of bed!
over rev on down shift ?or did a std rod bolt fail ?
--- they are not the easiest things too break.

[306rwd]

It will be the same if not better. like skids said aids in keeping the piston skirts cool. This is not such a major think on a n/a motor but is very useful when forced induction is involved.

Im curious as to how you managed to throw a leg out of bed!
over rev on down shift ?or did a std rod bolt fail ?
--- they are not the easiest things too break.

Oil starvation due to oil surge. Picked up on a b/e bearing which spun in the rod until the rod went black with the heat then bang!

Yes the sump was baffled. I have been using the same sump for years but I am driving and braking harder these days and out driving my baffled sump. I could baffle it better but have chosen to dry sump it to make sure.

The engine is in a forest rally carw that can be seen on my out of date website www.306rwd.co.uk.

[skiddz]

ouch...

i was gonna say that i dont think oil squirters would be a real problem but crank oiling would be an issue but with dry sump it probably wont

[30psi 4agte]

Oil starvation due to oil surge. Picked up on a b/e bearing which spun in the rod until the rod went black with the heat then bang!

Yes the sump was baffled. I have been using the same sump for years but I am driving and braking harder these days and out driving my baffled sump. I could baffle it better but have chosen to dry sump it to make sure.

306rwd.co.uk[/url].

ouch !! Thought it might have been something along those lines.

[TC1600]

The smallport block at worst will be equivalent to, and at best be better than your previous block, if the only difference is the oil squirters, then it will be as strong as what you had. As previously stated, the squirters will keep the pistons cooler, leading to better longevity. As the squirters run off the normal oil galleries, dry sumping the engine shouldn't affect how anything internal operates.

[306rwd]

The smallport block at worst will be equivalent to, and at best be better than your previous block, if the only difference is the oil squirters, then it will be as strong as what you had. As previously stated, the squirters will keep the pistons cooler, leading to better longevity. As the squirters run off the normal oil galleries, dry sumping the engine shouldn't affect how anything internal operates.

My concern was that the oil that is being squirted at the pistons could better be used going to lubricate the bearings.
Hopefully a dry sump system will have more oil pumping capacity than the standard pump and therefore be able to handle both.
The standard pump for the later engine is a higher capacity than the early pump where no squirters were fitted presumably to cater for extra oil requirement of the squirters.

[takai]

I run a smallport oil squirted engine in my race car with no issues whatsoever. The squirters are relatively small in size and shouldnt affect the pressure levels given in the engine at all. In addition the dry sumping system will be able to supply oil directly to the bearings under pressure without having to worry about surging.

Im suprised that you managed to destroy an engine in that method though, many people running a lot of sticky rubber havnt had much success in nuking engines in that way. Most of them just run winged sumps.

[306rwd]

I was suprised as well. I have been rallying using this sump setup with various spec 4AGE engines since 1995 and never had any poblems. Now all of a sudden I get 2 blow ups in 12 months.

[mullett]

i wonder if you've got a hidden problem...

RM.

[306rwd]

The first engine to blow ran from 2002 to 2005 competing in about 15 rallies before failing.

This latest engine to go was a fresh block, a new oil pump, the sump and pickup pipe are the same since 1995. Everything was properly cleaned with all the plugs out by my local engine builder before I assembled it as always.

I think it is just the lack of oil problem being caused by there being no oil at the pick up pipe.

[mullett]

Yup, sounds right to me...starting with such a fresh setup it really doesn't sound like it'd be some silly problem that killed both motors, more likely you're dead right, just a starvation problem...

RM.

[toddw]

FWIW I have a AE92 4AGZE block that I am building into a fairly serious N/A engine to go into my AE86. I have 11:1 Arias forged pistons and Pauter forged rods. My block only relies on the cooling from the hole in the rods squirting oil on the base of the piston. With the new rods there is no provision for this hole and hense no piston cooling. I contacted Pauter and Arias and the two answers were the same: That with a high RPM motor the spinning of the crankshaft is more than enough to cool and lubricate the piston an pin. Also Arias stated that being forged pistons they disapate any heat far better than cast pistons.

I was at first a little worried but these manufacturers are the best in the buisness and I guess they know more than I will ever know about rods and pistons. So I guess for a race/high rpm motor it is o/k to have no cooling. I guess Toyota design a motors for all driving conditions which include low speed/low rpm where there might be little piston cooling from oil splashing around.

So in answer to your question I would not be to worried using a block with little or no piston cooling via the oil squirters.

Hope this helps

Cheers
Todd