Clevo120Y

Hey guys, now that another race car that I developed the engine for is up and racing I thought I would start a new thread for it to update it's progress.
This is another XF but in the production class which is the next step up from the street stock cars. Another carby crossflow but SO much more freedom in development, modified intake manifold, ported head, balanced assembly, aftermarket ignition, electric water pump, 350 holley (modified), roller rockers etc etc but must be pump fuel.
So most of the stuff I have shared with you before but I will go over it again, this engine runs a 86da block, EF crank, 200 rods with 13cc pistons, ported XD head with 1.86in intake valves, 1.6in exhaust valves, yella terra adjustable rollers, head flows 212cfm. Comp is 10.5/1 with 6al msd ignition off XE dizzy, electric water pump, 1 3/4in long tube header. I ported the head, modified the intake manifold and built/modified the carb. I also speced out the bottom end but it was put together by the owner
The cam is a solid flat tappet that the owner already had so all my calculations are based around that. Cam specs are: In lift 562, ex lift 571, duration at 50 in 251 ex 254, ICL 105 LSA 106.5
 
So here are some pics of the head, manifold and carb work.
 

 

 

 

 









 

Hey guys, now that another race car that I developed the engine for is up and racing I thought I would start a new thread for it to update it's progress.
This is another XF but in the production class which is the next step up from the street stock cars. Another carby crossflow but SO much more freedom in development, modified intake manifold, ported head, balanced assembly, aftermarket ignition, electric water pump, 350 holley (modified), roller rockers etc etc but must be pump fuel.
So most of the stuff I have shared with you before but I will go over it again, this engine runs a 86da block, EF crank, 200 rods with 13cc pistons, ported XD head with 1.86in intake valves, 1.6in exhaust valves, yella terra adjustable rollers, head flows 212cfm. Comp is 10.5/1 with 6al msd ignition off XE dizzy, electric water pump, 1 3/4in long tube header. I ported the head, modified the intake manifold and built/modified the carb. I also speced out the bottom end but it was put together by the owner
The cam is a solid flat tappet that the owner already had so all my calculations are based around that. Cam specs are: In lift 562, ex lift 571, duration at 50 in 251 ex 254, ICL 105 LSA 106.5
 
So here are some pics of the head, manifold and carb work.
 

 

 

 

 









 

At the moment the workshop is getting a makeover for the relaunch of "Stumpers Heads & Manifolds" early next year. Something had to go to make room so the XD wagon got the chop for now, it's out at Wombats property, new shelving going up, some new tools on the way and some mould making gear to make carby tops that will be dyno tested and developed for sale later, hopefully a big year coming up.
Also the production XF that I did the head, manifold and carb for last year will have it's first run this weekend so I'm excited to see how that goes as well, this XF has been a back of the field car for years so let's see if we can get it up near the front.

On a better note the production XF went well for a first untuned run, it was the southern production series round so the states best came out to play, even tho the car ran middle to back of the pack it finished on the lead lap every race and it's lap times and top speed were competitive. Wolfy is the old boy driving it and he had a blast, he thinks it's fast and with more seat time should be right up there, he hasn't raced for a couple of seasons now so he will get better and he has never had a car this fast before either so looking good when I get some tuning time into it.

On a better note the production XF went well for a first untuned run, it was the southern production series round so the states best came out to play, even tho the car ran middle to back of the pack it finished on the lead lap every race and it's lap times and top speed were competitive. Wolfy is the old boy driving it and he had a blast, he thinks it's fast and with more seat time should be right up there, he hasn't raced for a couple of seasons now so he will get better and he has never had a car this fast before either so looking good when I get some tuning time into it.

Lmao, that sucks. Sure you'll have her ready and racing for the 3rd mate. Best of luck to you and the Wombat.

A small update, the 302 went 11.4 down the quarter and is now having the exhaust valves changed to a different shape, also the 750 carb is being replaced with an 850 unit. I am hoping this old girl gets to bottom 11's, he hasn't run it up to full revs yet so here's hoping she gets quicker.

I know but the thread needed at least one pic of an engine hahaha

The time this thread has been going a bank deposit would have cleared in my account for my engine

I know but the thread needed at least one pic of an engine hahaha

I know but the thread needed at least one pic of an engine hahaha

LOL I don't doub't you building em it's usually the OP... 

Here you go Rob
 

I put the same effort and detail into a stock engine as I would a race engine, it is the only way you can make sure an engine will last and that you can demand something from it.

Yeah have to agree with you there Sean...but again this argument is 100 years old and will still be going while ever there is oil fuel and these old shit boxes around to play with.
 
After all is said and done what you never see @ the end of threads is a actual engine. 

Don't know if I agree with stock springs being okay in any application.  this comment can lead to the impression that you can just leave the unknown quality factory valve springs in place and away you go. 
 
These engines are getting seriously on a bit now - yes some may have been replaced along the way - but who knows unless you actually check the tension of the springs. 
 
At the very least throw a new set of 'stock' springs in it but in reality why wouldn't you just throw in a good spring like an isky 235d and set them at 95 on the seat and never ever worry about valve springs again.  This way if you decide to up the ante a bit you don't ever have to fork out for springs up to .580" lift.
 
Towing demands reliability - reliability comes from using good parts and correct tolerances.  Sure as shit is good for the garden - the one part you skimp on will be the one that bites you in the arse. 
 
I'm with you Sly - less talk - more engine building - which reminds me I have a sump to build - see ya.

Built properly IS checking every clearance, on a slapper you can get away with chucking it together.

Cut it out will ya!! We have to race tomorrow night

You lot jinxed it, no racing tonight the car is broken, the diff and front end still need work and they run out of time. Next meet is the 3rd of Jan

Mossy revs his to 7500 and runs 120mph...guess they can rev

Cut it out will ya!! We have to race tomorrow night

As Stumper has proved by his detailed thread.

Also on what wagoon said, the stock rotating assembly is good, the street stock engine has stock crank and rods with arp rod bolts with no balancing, stock harmonic balancer and stock rockers. It gets spun to 6000 lap after lap without a failure, if it's put together nicely and tuned well they last fine.

This is the thing about a "mild" engine build...to do it properly costs the same as to make it a screamer. Thing about a xflow is they take bigger than what people think to work. Bigger carb bigger cam more compression more timing...they just have a stigma about been a 6cyl so you shouldn't put too much in it for some reason ? 

Don't use crow springs, half a season of racing and the crows went soft, set at 110lbs they were 85lbs when I tested them again, crap crap crap don't use them.