Friday, June 02, 2006

Engine is near done!

Needs the flywheel bolt holes enlarging and the head refitting. Took me most of the evening to complete. Still concerned about the 0.040" regrind on the crank now I have fitted a race cam...But my rods are 8% lighter than any others I could find so might help, gonna try and break it anyway, probably cap revs to 7000 with 7250 for emergencies. I didnt actually build the engine for this purpose so were into unknown territory!

TH7 is in and sump and timing cover back on.

Incidently I will be making a timing cover with a removable window for the next engine, ie you can tweak the cam on the rollers for max HP, might even forget that and covert the engine to a timing belt not a chain....easy!

Basically plan has changed I am now aiming for as much power at 5000-7000 rpm as possible, no messing with road cams, 7300rpm rev limit, I want 120HP or more?!

About time I added some images so here ya go!

"Standard 10" gasket set, our engines came from this motor, got more and bored out!! contains OE spec gaskets, I will use nothing else, no grey cheap rubbish. dont buy them all!!! I need some left!

I used Wellseal on the sump and timing cover this time, it doesnt come off and you can slap it on - doesnt end up filling the oil gauze on the pump, it stays where it is, I noticed a dribble on the back of the cam core plug was still in place from fitting the plug! It doesnt go hard it clots ! Its gummy horrible stuff, its no fix for warped over torqued sump trays etc, its liquid and works as a sealer not a bodging tool. Used it before, good stuff! Flange sealer is the devils work, if your needing that get off your ass and straighten out your fittings on a mirror.

Basically I save the rear main oil seal housing gasket, front engine plate gasket, sump and timing gaskets the rest is given back to the guy I brought it off or sold on ebay! I do not use silver-faced exhaust gaskets either, only grey on both sides, silver things are useless, another example of junk for sale. This kits very old!!!

When timing cams I make sure the number ie 103 install is set under straight chain on the loaded side -press as hard as physically possible on the area the tensioner runs in with a special tool, my thumb, this mimmicks the load/drag of the cam and drive train under load, you can't set a cam with a loose chain, flapping all over the gaff!! My cam is timed to 103.2degrees, its meant to be 103 - I couldnt get it more accurate for obvious reasons 8-) it took me 1hr and mulitple checks! It was 101 then 104 then 103.5 then 102.5 then 103.2 and I thought this obsessive enough! With a floppy chain you'll be 2degrees off, pissing in the wind -unless by pure luck you get it right, two deg can cost you 2hp or give you 3-4lbs of torque lower down etc...advancing and retarding cams has a marked effecr on the power character.

Here's my Cam Collection. Top to Bottom - TH7-TH5-Large journal Fast Road 89! I studied them a bit, guess what they're all different!!

Cheap cam lube, any Halfrauds etc...Does a billion cams for £4.50. Its not cam lube but its just good, sticks and clings to anything! Always use lube! Cam lobe loads are simply tremendous, one dry moment on startup you have seeded a lobe failure in the future.

TH5 lobe this is a new cam from a blank.

This must have been down to some grit or swarf in a hasty past rebuild, old engine, this was the Fast road 89, shame as it had been 30000 miles and been thrashed to 6500-7500 an awful lot! Great cam! Was mint bar this the lobes unmarked and followers had ZERO marking on them, luckily the journal in the block still had a firm press fit on the cam bearing, so saving my block for one last go its on + 60 anyway. Be like loosing an old friend when its had enough this time.

Bit more lift on the TH7!, this a new cam from a new blank the shaft thickness is far fatter than a reground and ramp angles more progressive, never bother with a regrind just buy new, the state of most old cams etc....

Time for some Marmite on toast then better get to bed before the twinkies come out and make me go mad!

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