X overthrottle Boddies

[phazed]

77racing said:

if you are interested in the JE 5.2 bottom end. I can post up the graph from my griff 5.2 which I used to use on the road and trackdays. just had one done as I plan on getting it back on the road in the next few weeks.Phazed will tell u how it goes, as he spent three years trying to get past it on track LOL

Soooooo, how was it?

[77racing]

eeerrrr except that lap then.

[77racing]

Slow M said:

Why don't you just press (or epoxy) a couple of inserts into the manifolds' bolt holes? you could even offset drill them, if required.

Best regards,
Bernard.

Yep never thought of that and easy to do.

[77racing]

Not much progress but the thinking is almost done .Thought been " measure twice, cut once" The bolt holes are not uniform so inserts are not possible as suggested to stop the front to back movement, so we have decided to put a small 4mm bolt tapped in each corner avoiding the water way allowing the manifold to be correctly repositioned every time. we are going to a lot of trouble to get the ports to match up with the least amount of restrictive overlap as possible. Hoping to maximise the flow benefits, after all I am chasing the top step of the podium at Spa Summer Classic later on in the year, no mean feat.

[MPoxon]

Looking good!

[77racing]

So Finally got the locating bolts done and on Monday I can drop heads off at Devon Racing for Chris to finish of and assemble the engine. As you can see I have a fair amount to take out of the casting to get it all matched up right. Looks like one side of tunnel more than the other that just needs a tickle. The four mil bolts you can see are my mounting bolts tapped into the casings but of course they go in from the other side on assembly. They are just in the wrong side at present to hold the template in place for the porting.

[77racing]

So after a lot of time filing and grinding the Manifolds now match the heads and the bodies, all apart from a good blow off and clean up ready to assemble.

[Matthew Poxon]

Wow they needed quite a lot of porting! Looks like you are getting there. Really nice piece of kit that crossover manifold.

[77racing]

Yep they needed quite a bit of work to get the best from them but I have a good feeling they are going to bring quite a bit to the party. On reflection i'm now not surprised they needed a fair amount of work to get everything to line up we are talking a Rover engine after all hopefully I can get the car a bit further on soon else the race season will be over before I know it. Only 12 weeks to Spa where I need what the set up will bring, fingers crossed.

[carsy]

Looking forward to seeing the results of this one.

[Kokkolanpoika]

Some porting work.. Near all done now.. Maybe some finnishing still..

My camera is not good enought to take better pick of valve seat.. Or my hand is shaking to mutch.. Will try to take another camera someday..

But here you can see idea to try take all out of rover original heads..

Some offset porting work to valve seat/valve pocket.. Approx 1mm offset. Throat diameter 90% 43mm inlet valve.





Exhaust short side radius is also fully ported ovality to valve seat is approx 1mm. Now it will flow without any turbulence..



Inlet flow will increase approx 35-40hp over stock 3 angle valve seat when make a test after porting.. But that flow bench testing is not the point. Only i want to show how this make a difference.. It is only some theoritically number. But now it will flow ~200cfm if some one is intresting.. Now it will use short side mutch mutch more than STD 3 angle valve seat/85% throat diameter.. Theoritically my flywheel power 393hp + 40hp more head flow + more agressive cam, it could be produse 40hp more.. + some home made merge collectors.. Those are ready now, in the pick they are still in progress..

[rev-erend]

Nice job on the collectors but you can buy Moroso 1.75 inch collectors in the USA for about $40 a pair ..

[Kokkolanpoika]

Cheapest what i found are approx 1x 85$ + vat and freight. Total over 250$ to Finland.. Those will cost me approx 120$ inc vat, 8x springs etc..
I think those 40$ merges are not real merges?

Can you post a link, ifthey are real..

[rev-erend]

It's the post cost that makes it expensive.

I put them in my suitcase when I went over there last..

I found these at JEGS for $69.99 - they even have a hole for the lambda

http://www.jegs.com/i/Dynatech/329/783-31230/10002...

[Kokkolanpoika]

In my mind those look like cheap STD slip on collectors..

Here you can see idea of real merge collector.






http://cdn.mandrelbends.com/media/catalog/product/...
Not mine, but this is what it should look like inside.. There must be a spike in the centre on collector..

Edited by Kokkolanpoika on Thursday 19th May 19:45

[77racing]

Kokkolanpoika said:

http://cdn.mandrelbends.com/media/catalog/product/...
Not mine, but this is what it should look like inside.. There must be a spike in the centre on collector..

Edited by Kokkolanpoika on Thursday 19th May 19:45

I can tell you the spike is worth about 4bhp.

[rev-erend]

My collectors have a spike just like that but a bit smoother..

[77racing]

Time to update this as it has been quite a while. I Have been waiting and waiting and waiting for the chap who I commissioned a 4.8lt short engine build, to deliver on the promises but having now missed a whole year I have decided to give up on that route and have had my hand forced higher up my back now as the original 4.5lt engine I have been racing with decided to drop a valve head in at Thruxton four months ago and the engine will take a fair bit of time and money to repair as you can imagine.

So I have now purchased a 5lt all singing and dancing full engine from JE which was a cancelled order sat on his shelve ready for dyno work. He is going to finish off the work and change a couple of things for me and we should take delivery mid January. In the mean time I have been very busy with other things on the car such as repairing some accident damage down one side and decided to refresh the whole car so have re-sprayed the whole car and now I am nearly ready to paint the front engine bay chassis area while I,m at it. It is an original 1989 challenge car so after all these years been thrashed round a race track I thought I would give it a bit of TLC without loosing the patina of an old race car.

[phazed]

Why the so-called engine builders mess around, I really don't know.

It only takes a few days to build an engine and in fact, a competent professional with all the gear in front of him will have it built in a day.

Those same few words, promises, promises, promises and promises.

Would you like to share the specification Perry?

[Boosted LS1]

^ The main delay with a custom build will be waiting for the pistons to be produced and delivery. That can be 3 months and then 3-4 weeks for crank balancing while the blocks being bored/honed. After that the engine can be built.