4k

[joshz18]

my 4k in my ke70 keeps f@$king these since the twin 40mm solexs were fitted, My theory is due to it having a stock exhaust and exhaust manifold is that its getting all this air and fuel in so quickly but it can;t get it out, causing extreme heat and pressure, there for blowing out the weakest link. Am i just full of shit or could i be correct. Also to fix this problem i have considered putting extractors and a 2 inch exhaust system on it,

Do you think this will solve my problem? also where can i purchase extractors for these from at a resonable price

 

cheers josh

[Taz_Rx]

I reckon your problem is 2x different thinkness mounting flanges on the weber manifold and ex minfold.

The weber manifold is probably slightly thicker, hence the ex manifold isn't getting pressed up to the head at tight as it should be. This is pretty easily fixed by skimming the bigger one so they're both the same thinkness.

 

I had the same issue with a 7ke manifold which was 12mm, and my turbo exhaust manifold flange was 10mm think. Didn't realise until I tried to assemble it. Inlet mani was firm and the ex mani wobbled around.

 

Saying that, extractors still wouldn't be a bad idea. They're going to give you better flow and release some more potential from the sidies. :y:

You will still need to check the above when doing this though.

[Taz_Rx]

Oh and if you're using shitty 2x piece ACL gaskets then that would also be half your problem, cause I'm guessing it burns out between ports 2 & 3 where the gaskets but up.

Go to Bursons and order a permaseal EM30 which is a 1x piece steel gasket. If you get a "valued customer"/trade price you should be able to get one for around $12, which is actually cheaper than the shitty ACL ones. :y:

 

Not the best pic, but the top head still has an old EM30 stuck to it. Note the inlet ports are big-port sized, but this doesn't in any way effect using one on a small port head......

 

Edited June 18, 2009 by Taz_Rx

[joshz18]

ahk thats awesome thanks for the info, i didnt even think about that, and yeah its used to acl 2 piecers, will have a good look at it on the weekend and grab one of those gaskets. you don't know of any extractors floating around being the k series wizz in tassie? haha

[Taz_Rx]

Nah not local sorry mate. They always get snapped up pretty quick.

 

They do come up for sale on the mainland quite regularly though like the link I put in your wanted thread. :y:

[philbey]

I'm running the 2 piece gaskets with my twin carbs and haven't had issues yet, not to say I wont in the future though. While you have the manifolds off, get the single piece.

 

Definitely take a look at the thickness of each of the ears on your manifold. If it's a lynx item, you can garauntee that they will vary significantly, they'll probably even have some taper on them.

 

It's not hard to fix, just get a file onto them, not on the Head side of the manifold obviously. Your exhaust manifold should be quite accurate.

 

If you get extractors you'll likely find they have a thinner flange and you'll need more filing.

[rob83ke70]

Your car isn't running too hot? check it with an infrared thermometer. Also, make sure that the manifold bolts or studs/nuts are clamping the gaskets tight enough. Then make sure the inlet/exhaust flanges are the same thickness.

 

I found the only way to make them seal properly and last on the ke55 (twin su's and extractors) was to coat both sides of gaskets (2 piece cheap shitty ones) with silastic and then assemble using allen headed bolts (the diameter of the head fits beautifully in the space provided by toyota to clamp the manifold flanges) and check tension a few times after you've run it for a bit.

 

I would HIGHLY reccommend using allen headed bolts to secure the manifolds, the studs were a pain because the nuts would bottom out on the thread and then the manifolds would not squish the gasket tight enough. Aftermarket bolts have too big of a hex head (automotive bolts are smaller heads for same size shank) and the allen headed high tensile bolts are easy enough to get, weren't really dear, and work absolutely spot on and look neat as. The only downside is it takes a little bit more time/effort/care to line up manifolds and put all bolts in and get them started before you clamp anything down really tight.

 

Robert.

[Felix]

I'm a fan of using manifold studs, just use enough washers to stop the nuts bottoming. Saves stripping the threads on the head.

 

The studs can be a pain though. I have to remove manifold side engine mount/xmember nut and jack the motor up a bit to be able to slide my extractors off to remove them in my ke15. It sux but I would rather do that than have to remove the head to helicoil it due to stripped threads. No biggy, just adds a few extra minutes, but the bonus is the manifolds slide straight on when you put it back together.

 

The best manifold gaskets ever were the old asbestos based one piece extractor gaskets. They were great as they were resuable and sealed really really well. The current metal ones just aren't in the same league, though are better than the two piece ones. Guess a lot of it has to do with how accurately the thickness of the manifold and extractors are matched.

 

Filing or dremeling the manifold ears as Philbey stated is the best way to go. Dummy them up with the engine on a stand if you can, rather than in the engine bay. Makes life so much easier.

 

In the past I've used the pressed metal manifold washers from holden red motors, and filed one side of them to account for varying flange thickness. While it works it is fiddly.

[rob83ke70]

I drop washers and nuts and fight with them a bit. I seemed to get along better with the allen head bolts. Standard studs/washers/manifold nuts are good, but the allen bolts worked for me. That is a concern about stripping the threads if I don't start them properly, but a little bit of patience, its all good.

 

Robert.

[Felix]

Yea do whatever works for you.

 

I guess a lot of it has to do with the extractors you run. If the extractors run a one piece flange bolts are fine, and you don't really need to worry too much about cross threading. If however the extractors don't run a one piece flange then over time you may have to contend with a bit of warpage which can make alignment and getting the bolts started a lot more dicey.

 

My ke15 has a set of Pacemakers and they have warped over time due to not having a one piece flange, plus age. They were a bitch to get manifold bolts in straight, hence the move to studs. One piece extractor gaskets are a must with these. Inlet manifolds have to have the ears ground down to the extractor flange thickness.

 

My ke16 on the other hand has a set of Perry extractors with a one piece flange, they are easy as to line up, and have the same thickness as standard k series inlet manifolds. They are happy to run the two piece gaskets and the standard manifold bolts.

[philbey]

Seriously josh, don't silastic up your manifold gasket - It's a poor solution! There is a reason your gaskets aren't sealing, and silastic is a poor answer to the problem.

 

Get the 1 piece gasket, make sure all your manifold ears are flat, planar and the same thickness and you won't have a problem.

[Taz_Rx]

No matter now!

 

Josh is a car-slut so he's already sold the vehicle in question. :bash:

[rob83ke70]

The silastic wasn't the ideal solution, but cheaper and quicker than pulling the head off and the manifolds apart to get everything machined.

 

My extractors have a once piece flange the same thickness as the manifold ears. Easy as. I'd get the shits if the extractor flange was two pieces and a different thickness..... thats poorer engineering than my silastic solution lol.

 

Robert.

[SLO-030]

My 4k had blown the gasket around EVERY exhaust port. I found that when i did the HG. But It was due to my diff hitting an squashing up the exhaust where it passed over.